std 147 2002r ppr2 (chair approved r1)

BSR/ASHRAE Standard 147-2002R

Public Review Draft

_____________________________________

ASHRAE Standard

Proposed Revision of Standard 147-2002, Reducing the Release of Halogenated Refrigerants from Air-Conditioning Equipment and Systems Second Public Review (May 2011) (Complete Draft for Full Review) This draft has been recommended for public review by the responsible project committee. To submit a comment on this proposed addendum, go to the ASHRAE website at http://www.ashrae.org/technology/page/331 and access the online comment database. The draft is subject to modification until it is approved for publication by the ASHRAE Board of Directors and ANSI. The current edition of any standard may be purchased from the ASHRAE Bookstore @ http://www/ashrae.org or by calling 404-636-8400 or 1-800-527-4723 (for orders in the U.S. or Canada). The appearance of any technical data or editorial material in this public review document does not constitute endorsement, warranty, or guaranty by ASHRAE of any product, service, process, procedure, or design, and ASHRAE expressly disclaims such. May 13, 2011. This draft is covered under ASHRAE copyright. Permission to reproduce or redistribute all or any part of this document must be obtained from the ASHRAE Manager of Standards, 1791 Tullie Circle, NE, Atlanta, GA 30329. Phone: 404-636-8400, Ext. 1125. Fax: 404-321-5478. E-mail: [email protected]. AMERICAN SOCIETY OF HEATING, REFRIGERATING AND AIR-CONDITIONING ENGINEERS, INC. 1791 Tullie Circle, NE Atlanta GA 30329-2305

BSR/ASHRAE Standard 147-2002R, Reducing the Release of Halogenated Refrigerants from Refrigerating and Air-Conditioning Equipment and Systems (Second Public Review Draft)

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BSR/ASHRAE Standard 147-2002R Reducing the Release of Halogenated Refrigerants

from Refrigerating and Air-Conditioning Equipment and Systems

CONTENTS SECTION PAGE Foreword......................................................................................................................................... 3 1 Purpose.................................................................................................................................... 4 2 Scope .......................................................................................................................................... 4 3 Definitions.................................................................................................................................... 4 4 Design......................................................................................................................................... 7 5 Product Development................................................................................................................. 9 6 Manufacture............................................................................................................................. 10 7 Installation................................................................................................................................... 11 8 Service/Operation/Maintenance/Decommissioning.................................................................. 12 9 Refrigerant Recovery, Reuse, and Disposal................................................................................ 14 10 Handling and Storage of Refrigerants ....................................................................................... 15 11 Normative References.............................................................................................................. 16 Annex A: Recommended Procedures and Practices...................................................................... 17 Annex B: Training of Personnel.................................................................................................... 34 Annex C: Informative References ................................................................................................ 34 Annex D: Bibliography.................................................................................................................. 35


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(This foreword is not part of this standard. It is merely informative and does not contain requirements necessary for conformance to the standard. It has not been processed according to the ANSI requirements for a standard and may contain material that has not been subject to public review or a consensus process. Unresolved objectors on informative material are not offered the right to appeal at ASHRAE or ANSI.)

FOREWORD When the potential link between release of chlorofluorocarbons (CFCs) and depletion of stratospheric ozone was first discovered, ASHRAE appointed a task group to study the issue and to develop appropriate policy and program recommendations to the Board of Directors. In response, a comprehensive action program was initiated. It included research, education, communication, and training directed toward the various aspects of the CFC issue. A part of this program was the development of a guideline for reducing CFC refrigerant release. This was published as ASHRAE Guideline 3-1990, Reducing Emission of Fully Halogenated Chlorofluorocarbon (CFC) Refrigerants in Refrigeration and Air Conditioning Equipment and Applications. Since that date, it has been determined that all releases of chlorine containing refrigerants, hydrochlorofluorocarbons (HCFCs) as well as CFCs, contribute to depletion of the stratospheric ozone layer. Not long after, it was also determined that the release of CFCs, HCFCs, and hydrofluorocarbons (HFCs) contributes to global warming, adding new urgency to controlling their release. At this time, in 1996, Guideline 3 was revised to reflect this need for a more stringent policy, and in 2002 ASHRAE published Standard 147, Reducing the Release of Halogenated Refrigerants from Refrigerating and Air-Conditioning Equipment and Systems. Standard 147 took many of the recommended practices of Guideline 3 and made them mandatory requirements, thus further increasing the stringency of the guideline, which was then withdrawn. However, some of the material from Guideline 3 was preserved in the standard in informative annexes that provide recommended practices that are not required by the standard. This revision of Standard 147 updates the 2002 edition by expanding the number of equipment types and systems covered, by providing significant requirements for field-erected systems, by adding more sections on leak checking, by adding requirements for systems with larger charges, by addressing the shipping and handling of containers for refrigerants, and by making many formerly recommended practices mandatory.


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1. PURPOSE This standard establishes practices and procedures that will reduce inadvertent release of halogenated refrigerants.

2. SCOPE The practices and procedures in this standard cover release reduction of halogenated hydrocarbon and halogenated ether refrigerants in the following circumstances:

(a) from stationary refrigerating, air-conditioning, and heat-pump equipment and systems; (b) during manufacture, installation, testing, operation, maintenance, repair, and disposal of such equipment and

systems.

3. DEFINITIONS Although the following terms may have broader interpretations elsewhere in the industry, their specific meanings as used in this standard are as follows. CFC (chlorofluorocarbon): a fully halogenated (no hydrogen remaining) halocarbon containing chlorine, fluorine, and carbon atoms. equipment type: a classification used to distinguish between the different kinds of refrigerant-containing systems and equipment covered by this standard.

type 1 component: single refrigerant containing piece of a refrigeration system, (Examples: thermostatic expansion valve [TXV] body, TXV power head, valves, receiver; controls, tube.) type 2 - small assembly: the extension of the refrigerant volume by brazing/ welding/ mechanical connection of components and can include other hardware. Internal volume is less than 61 in3 (1 liter). type 3 large assembly: a further extension of the refrigerant volume by brazing/welding/mechanical connection of multiple components. Internal volume is equal to or greater than 61 in3 (1 liter). type 4 - appliance: A very small packaged piece of refrigeration equipment that is installed by the consumer and has a design refrigerant operating charge of less than 5 lb (2.3kg) of refrigerant. type 5 - small packaged equipment: A small piece of refrigeration equipment manufactured, assembled in its entirety and which is typically installed by a contractor and with a refrigerant design operating charge of less than 50 pounds (23kg) per circuit. type 6 - small assembled equipment: small refrigeration equipment that is assembled and installed by a professional and contains a refrigerant design operating charge of less than 50 lb (23kg) per circuit. These are typically two assemblies, a condensing unit and an evaporator/air handler but may have as many as 3 AHU/evaporators. type 7 - large packaged equipment: a large piece of refrigeration equipment manufactured and assembled in its entirety in a manufacturing facility and which is installed by a professional, and contains a refrigerant design operationg charge of 50 lb (23kg) or more per circuit. type 8 - large assembled equipment: large refrigeration equipment that is assembled and installed by a professional and contains a refrigerant design operating charge of 50 lb (23kg) or more per circuit. These are typically two or three pieces being a compressor(s), evaporator(s), and condenser(s) type 9 small field erected system: a system that is professionally and specifically designed, and erected for a particular application. With a refrigerant design operating charge of less than 50 lb (23kg), a system of this type may contain multiple compressors, evaporators, and condensers. type 10 large field-erected system: a system that is professionally and specifically designed, and erected for a particular application. With a refrigerant design operating charge of 50 lb (23kg) or more of refrigerant, a system of this type often contains multiple compressors (rack), evaporators, and condensers as well as heat recovery.

halocarbon: any of a class of compounds containing carbon, one or more halogens, such as fluorine, and sometimes hydrogen. HCFC(hydrochlorofluorocarbon): a halocarbon that contains fluorine, chlorine, carbon, and hydrogen. hermetically sealed system: a factory-charged refrigerating system that is welded, brazed, soldered, or otherwise joined together in such a manner as to create a completely sealed system. HFC(hydrofluorocarbon): a halocarbon that contains only fluorine, carbon, and hydrogen. holding charge: an inert gas used to temporarily create a positive pressure and thereby avoid the ingress of air or moisture during shipment or storage.


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joint, brazed: a gas-tight joint obtained by joining metal parts with alloys that melt at temperatures higher than 800F (426C) but less than the melting temperatures of the joined parts. joint, mechanical: a gas-tight joint obtained by joining metal parts through a positive-holding mechanical construction. joint, soldered: a gas-tight joint obtained by joining metal parts with metallic mixtures or alloys that melt at temperatures above 400F (204C) but not exceeding 800F (426C). joint, welded: a gas-tight joint obtained by the joining of metal parts in the plastic or molten state or through the use of filler metals that melt at temperatures 800F (426C) and above. maintenance: the upkeep of property or equipment in order to keep it in an existing state (as of repair, efficiency, or validity) and to preserve it from failure or decline. maintenance, corrective: a type of maintenance program where failures are corrected or repaired as they occur. Corrective action is always performed after failure occurs. maintenance, planned: a type of maintenance program in which resources are invested in prudently selected functions at specified intervals. In this type of program, all functions and resources are planned, budgeted, and scheduled. maintenance, predictive: a type of maintenance program in which statistically supported objective judgment is used. Non-destructive testing, chemical analysis, vibration and noise monitoring, as well as visual inspection and logging are all used to predict when a particular part or system might fail so its useful life can be extended and maximized. maintenance, preventive: a type of maintenance program in which inspections, checks, servicing, and replacements are performed according to either a predetermined schedule or condition based monitoring indicators. Durability, reliability, efficiency, and safety are the principle objectives. Preventive maintenance embodies two concepts: planned and predictive maintenance. maintenance, program: a systematic approach to maintenance in terms of time and resource allocation. It documents the objectives and establishes the criteria for evaluation and commits the maintenance department to basic areas of performance such as prompt response to mechanical failure, maintenance, and attention to planned functions that protect the capital investment and minimize downtime or failure response. pressure, design: the maximum allowable working pressure for which a specific part of a system is designed to operate under normal or abnormal conditions, as defined in a relevant standard, such as UL 1995. 16 pressure, high: as this term applies to refrigerations systems, it refers to gage pressure at room temperature (74F [23.3C]) that is typically more that 100 psig (689 kPa). Common high-pressure refrigerants include R-22, R-502, R-404A, R-407A, R-407C, R-410A and R-507A. pressure, low: a as this term applies to refrigerations systems, it refers to absolute pressure at room temperature (74F [23.3C]) that is below ambient pressure absolute. Low-pressure refrigerants include R-11, R-113, and R-123. pressure, maximum working: (see pressure, design). pressure, medium: as this term applies to refrigerations systems, it refers to gage pressure at room temperature (74F [23.3C]) that is greater than atmospheric pressure but typically less that 100 psig (689 kPa). Common medium-pressure refrigerants include R-12, R-500, R-134a, and R-245fa. pressure, operating: the pressure occurring at a reference point in a refrigerating system when the system is in operation. pressure-relief device: a valve or rupture member designed to relieve excessive pressure automatically. prevention-of-vacuum system: a refrigerant pressure control system that prevents refrigerant loss and infiltration into idle low-pressure chillers and is also used to pressurize for leak testing without the use of non-condensables. purging: removing non-condensable gases from the system. purging device: an automatic, semiautomatic, or handoperated device that removes non-condensable gases introduced into a system during charging, servicing, or normal operation. receiver: a vessel in the refrigerating system designed to ensure the availability of adequate liquid refrigerant for proper functioning of the system and to store the liquid refrigerant when the system is pumped down. reclaim: to process used refrigerant so that it meets new product specifications. recover: to remove refrigerant in any condition from a system and store it in an external container. recycle: to reduce contaminants in used refrigerants by separating oil, removing non-condensables, and using devices such as filter driers to reduce moisture, acidity, and particulate matter. refrigerant charge: the mass of refrigerant in a closed system. refrigerant, design operating charge: the mass of the refrigerant required for proper functioning of a closed system refrigerant circuit: an assembly of refrigerant containing parts connected to allow the flow of refrigerant in the refrigerating cycle. The refrigerant-containing parts are considered part of the circuit even if isolated by a valve. A system or equipment may be considered to have multiple circuits only if there is no intended path for the refrigerant to cross over from circuit to circuit.


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refrigerant release: any movement of refrigerant out of its containment and into the atmosphere, including, but not limited to, movement by a leak, by an action of filling or testing, or by failure. rupture disc: a safety device that is designed to rupture at a predetermined pressure. seasonal adjustment: the adding of refrigerant to a refrigeration or air conditioning system due to change in ambient conditions caused by a change in season, followed by the subsequent removal of refrigerant in the corresponding change in season where both the addition and removal occurs within one consecutive 12 month period. topping off: adding refrigerant to a refrigeration or air conditioning system in order to bring the system to its normal operating charge. trace gas: a gas that is detectable by a leak detector and can be mixed with an inert gas. Typical trace gases are helium, hydrogen, and most refrigerants. vacuum, deep (high vacuum): a vacuum of 1000 m Hg (micron) (130 Pa) or less of absolute pressure. valve, pressure-relief: a pressure-actuated valve held closed by a spring or other means and designed to automatically relieve pressure in excess of its setting. valve, purge: a device to allow non-condensable gases to flow out of the system.


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4. DESIGN This section covers the compliance requirements for designers of air-conditioning and refrigerating systems and components. For all equipment and systems described in this section, the following requirements shall be met: Informative Note: The understanding and application of established techniques in both the design and construction of refrigerating systems provide a good foundation for the prevention of refrigerant release to the atmosphere. Examples of recommended design practices and techniques to minimize refrigerant leakage are given in Annex A. 4.1 Safety. All equipment and systems shall be designed in accordance with a recognized national standard, such as ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems1 or UL Standard 1995. 16 4.2 Documentation. Documentation to instruct field personnel how to install, operate, and service refrigerating equipment to minimize refrigerant release shall be provided for factory-built equipment and for field-erected systems. 4.3 Compressors Leaks associated with compressors may be related to the design of the compressor (e.g., oil pan, motor bell, oil pump) or to the associated equipment fitted to it (e.g., gauge and cutout connections, relief valves, and connected piping). Compressors shall meet the following requirements to minimize the possibility of leaks. 4.3.1 Shaft Seals. Seals shall be designed with materials compatible with the refrigerant and oil to be used in the compressor. Informative Note: Shaft seals used in open-style compressors can be a source of refrigerant leakage. 4.3.2 Vibration. To minimize leakage due to vibration, compressors, compressor mountings, and piping connections shall be evaluated to see that vibration-induced stresses do not exceed material endurance limits. If the equipment is not evaluated for material endurance testing, then all copper tubing that is of an outside diameter of 3/8 in.[9.5mm] or smaller (excluding suction and discharge) and are connected to compressors or assemblies that are not isolated from compressor vibrations shall be constructed with vibration loops to minimize fatigue at connections. 4.3.3 Semi-Hermetic Compressors. Materials used for gaskets and O-rings shall be compatible with the refrigerant and lubricant used. All bolts shall be torqued to the required level as set by the compressor manufacturer. 4.4 Condensers and Evaporators. Connections shall be designed so that vibrational stresses from the suction, discharge, and liquid line loads at the condenser and evaporator joint(s) do not exceed material endurance limits. All electrical power and control wiring greater than 100V shall be routed and tethered in a way where an energized, severed wire cannot come into contact with any refrigerant tubing. Thermal expansion valve (TXV) equalizer tubes shall be routed and secured to support the weight of the tube. 4.4.1 Air-to-Refrigerant Condensers and Evaporators. These components shall be designed for the ability to withstand stress, vibration, and corrosion under normal operation and during transport. Tubing supports shall be designed to minimize vibration, to provide protection against abrasion due to movement, and to allow for thermal expansion. 4.4.1.1 The user or the users designated agent shall select materials that will prevent corrosion failure in the installed environment. 4.4.2 Liquid-to-Refrigerant Condensers and Evaporators 4.4.2.1 These components shall be designed to withstand stress, vibration, and corrosion under normal operation and during transport. Tubing supports shall be designed to minimize vibration, to provide protection against abrasion due to movement, and to allow for thermal expansion. 4.4.2.2 The characteristics of fluids used in liquid chillers and liquid-cooled condensers vary widely and can lead to premature failure of tubes, resulting in release of the entire refrigerant charge. The user or the designated agent shall


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select tube materials, tube configurations, tube-wall thicknesses, and filtration/ treatment techniques suitable for the fluid characteristics. 4.4.2.3 The user or the users designated agent shall select tube and water-side materials that will prevent corrosion failure when used with the intended fluids in the installed environment. 4.4.2.4 To prevent freeze-up of water-chilling machines during operation, safety controls shall be provided by the manufacturer of the equipment. Examples include, but are not limited to, refrigerant pressure control and/or refrigerant temperature control. See Section 7.6 for requirements when the system is not in operation. 4.4.2.5 When utilizing a brazed plate heat exchanger as an evaporator, insulation of the entire unit and attached tubing is important. This insulation prevents the formation of frost in critical areas that may force the plates to separate and eventually leak. Equipment and attached tubing shall be insulated to prevent frost from forcing plates to separate. 4.5 Piping, Tubing, and Connections 4.5.1 Minimized Connections. Systems shall be designed in such a manner as to minimize the number of fittings and connections. Tapered pipe threads shall not be used for fittings in refrigerant circuits unless the threads are back-welded or sealed by equally effective means. Single-flare fittings shall not be used. 4.5.2 Flanged Joint Seals. Designers shall specify flanged joint seal materials that are compatible with both the refrigerant and refrigerant oils to be used in the system. 4.5.3 Support. Pipe and tubing supports shall be designed to provide protection of tubing components against external abrasion due to movement. Tubing inside refrigerated cases in Equipment Types 9 & 10 shall be supported by the case at least every 36 in. (91 cm) of tube length and within 12 in. (30 cm) from any connection or elbow. 4.5.4 Corrosion Prevention. External protection shall be specified to prevent corrosion of metal components that contain refrigerant or are in direct contact with refrigerant-containing components. 4.5.5 Over Pressurization. To prevent hydrostatic over pressurization due to thermal expansion, liquid-containing system parts shall be protected as specified in Section 9.4.3 of ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems.1 Exemptions. Equipment Types 4, 5 and 6 that is approved by a nationally recognized testing agency shall be exempt from all provisions of Section 4.5 except the provisions in Section 4.5.1 regarding single flare fittings and tapered pipe threads. 4.6 Isolation Valves. Isolation valves shall comply with one of the following: 4.6.1 The valve stems are sealed by internal diaphragm. 4.6.2 The valve has a spindle, with a tethered cap . 4.6.3 The valve meets the requirements of Section 6.2.1 4.7 Access Valves for Charging, Evacuation, or Both. Access valves or couplings, except as noted below, shall have a tethered metal-to-metal or metal-to-o-ring sealing surface to prevent leaking through the cap and shall be provided for evacuation and liquid charging of refrigerating systems. Caps shall meet the leakage requirements of Section 6.2.1. For Equipment Types 4, 5, and 6 using hermetically sealed compressors, an equally effective design feature (e.g., process tube or stub) shall be considered to meet the requirements of this section 4.8 Relief Devices System relief devices shall conform to the requirements of ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems.1 Equipment types 7, 8, and 10 shall have an alarm that notifies personnel of high refrigerant


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pressure that can result in refrigerant release through the relief device(s). Medium and high pressure refrigerant systems shall not use a rupture disc as the sole relief device venting to the atmosphere. Exemptions to 4.8: Equipment Types 4, 5, & 6 having sealed systems approved by a nationally recognized testing agency shall be considered to comply with the provisions of Section 4.8. 4.9 Purging Devices 4.9.1 Sub-atmospheric Pressure. Purging devices shall be provided for Equipment Types 7, 8 & 10 that have any portion of the system that operates at sub-atmospheric pressure. New equipment designs shall specify purging devices that release less than one unit mass of refrigerant per unit mass of air as tested by ARI Standard 580, Performance of Non-Condensable Gas Purge Equipment for Use with Low Pressure Centrifugal Chillers.2 4.9.2 Infiltration. Systems with purges as described in Section 4.9.1 shall be designed so that air infiltration under idle storage conditions 74F (23.3C) saturated refrigerant temperature and 14.7 psia (101.235 kPa) atmospheric pressuredoes not prevent systems from starting and operating. To conform, the system shall include one or more of the following: (a) A purge unit that operates while the system is under idle storage conditions. (b) A prevention-of-vacuum system that prevents air infiltration while the system is under idle storage conditions. (See Section A2.9.1 in Annex A for an explanation.) (c) A system design means that allows a system to start and operate when air infiltration has occurred under idle storage conditions. Any means to remove air from the chiller shall conform to the emissions requirement of Section 4.9.1. 4.9.3 Alarm. The purge unit shall automatically indicate purge activity and shall alarm if the amount of purging exceeds the system manufacturer's preset limit. 4.10 Storage Capability In large field-erected systems, such as supermarket refrigerating systems, one or more receivers shall be provided for the system to store the charge as necessary to service various components. Systems shall be exempt from this requirement if the condenser is large enough to contain the entire charge, is fully isolatable and is protected by a pressure-relief valve in accordance with ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems.1 4.11 Shipping and Package Testing Procedures The following testing procedures shall be used to ensure products arrive in acceptable condition: Compression strength tests: ASTM D6423 and ASTM D45774 Vibration tests: ASTM D9995 and ASTM D47286 Mechanical handling tests: ASTM D 60557 and ASTM D61798 Shock and impact tests: ASTM D8809 and ASTM D527610 4.12 System Monitoring All new Equipment Types 7, 8 & 10 with a refrigerant design operating charge greater than 500 lb (230kg) shall be equipped with a feature to alert the owner that the system is releasing refrigerant or has released enough refrigerant to affect system performance. 5. PRODUCT DEVELOPMENT This section of the standard describes compliance requirements for products during their development phase. 5. 1 General. When components or systems are being tested for refrigerant leakage during development, the practices and procedures specified in Sections 7.17.5 shall be followed. A refrigerant charge used for operational testing during development shall not be released to the atmosphere following development tests or at the end of the development period. The refrigerant shall be removed and stored in a suitable container. 5.2 Refrigerant Handling The laboratory shall be equipped with a recovery/recycling system and storage capacity for holding charge recovered from any individual test unit in the laboratory. When servicing of a recovery/recycling unit is required, refrigerant in the unit shall be recovered and recycled or reclaimed in the same manner as that from test systems.


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5.2.1 Recovery. Upon completion of tests, the refrigerant shall be recovered from an experimental system. It is recognized that sometimes the recovered refrigerant must first be put into a container to determine or confirm charge levels, but ultimately all refrigerant shall be recovered into appropriate storage devices as required under Section 10. Refrigerant that is known to be contaminated, as with a motor burnout, for example, shall be recovered into proper containers and recycled, reclaimed, or disposed of as described in Section 9. 5.2.2 Inventory Record. A refrigerant inventory record shall be maintained to account for virgin material received into the laboratory and material shipped for reclaim or destruction. This inventory must include the types and quantities of refrigerant received and shipped for reclamation or destruction and the dates of receipt and shipment. 5.2.3 Test Facility Air Conditioning Equipment. Test facilities have conditioning equipment that provides a controlled environment for testing. This equipment shall be constructed and installed in accordance with this standard and checked for leaks on a regular basis. When servicing is required, the refrigerant shall be recovered and recycled or reclaimed in the same manner as that from test systems.

6. MANUFACTURE This section applies to the manufacture of all equipment types. Informative Note: Refer to Annex A for practices and procedures that are recommended but not required for compliance with this standard. 6.1 General. All equipment, components, and complete systems shall be cleaned, dried, evacuated, leak-tested, and sealed before shipment. Components or sub assemblies that will be tested in a larger assembly further in the manufacturing process shall be exempt from this requirement. 6.2 Factory Leak Testing 6.2.1 Leak Rate Specification. All equipment types shall be leak-tested by either a leak rate measurement method or a leak location method such as those described in Annex A4.3. The measured leak rate shall not exceed the values established for the method selected in Table 1 (when tested at the conditions prescribed in ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems, Section 9.14.1).1 The components of Equipment Types 6, 9, and 10 shall be tested as Type 1, 2 or 3 assemblies, as appropriate.

Table 1: Equipment Manufacture Leak Threshold Limits Equip. Type

Description Leak Rate Measurement Threshold Leak Location Method Threshold

Type 1 Component 0.1oz / year 0.1oz / year / joint Type 2 Small Assembly 0.5oz / year 0.1oz / year / joint Type 3 Large Assembly 1.0oz / year 0.1oz / year / joint Type 4 Appliance 1.0oz / year 0.1oz / year / joint Type 5 Small Packaged 3.0oz / year 0.1oz / year / joint Type 7 Large Packaged Greater of 15oz / year or 0.25% of the charge 0.1oz / year / joint Type 8 Large Assembled Greater of 15oz / year or 0.25% of the charge 0.1oz / year / joint

6.2.2 Leak-Test Gas. CFCs are prohibited by law from use as a leak test gas. HCFC or HFC refrigerants are prohibited by this standard for use as leak-test gases unless they are recovered. A mixture of a trace quantity (no more than 10% by mass) of non-CFC halocarbon refrigerant, such as HCFC-123, with nitrogen may be used as the leak-test gas. Leak-test gas containing halocarbon refrigerants shall be recovered and reused. 6.3 Operating Test Gas Recovery Refrigerant used during the manufacture and operational testing of systems and components shall be recovered from systems and components prior to repair or re-work.


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6.4 Evacuation Systems shall be evacuated to 1000 microns of Hg and held long enough to remove moisture. 6.5 Holding Charge A halogenated refrigerant shall not be used as a holding charge. 6.6 Purging Purging with inert gas is required during brazing to prevent oxidation, which can cause plugged driers, filters, strainers, dirty oil, and compressor failure. 7. INSTALLATION This section specifies the installation requirements that must be met to comply with this standard. It applies only to Equipment Types 6 through 10. Informative Note: Practices and procedures that are recommended but not required for compliance with this standard are described in Annex A. 7.1 Installation of Equipment Types 6, 8, 9, and 10 7.1.1 General. All piping, tubing, and connections shall be installed as required by Section 4.5. 7.1.2 Major Considerations 7.1.2.1 All cut piping shall be deburred and metal filings removed to prevent damage to the compressors and refrigerating system parts, such as shaft seal, compressor bearing, motor, and capillary tube. 7.1.2.2 All tube and fittings shall be thoroughly cleaned prior to assembly. Both the outside of copper tube and the inside of fittings must be bright and clean before brazing. Braze filler metal selection shall be consistent with the types of materials being joined. 7.1.2.3 Except as provided for in Section 4.5.1, tapered pipe thread connections shall not be used to join pipe or tube to fittings, valves, and other components. 7.1.2.4 The gasket material used on flanged connections shall be of a type and grade that is compatible for use with refrigerants and refrigerant oils of the types being used. 7.1.2.5 Equipment shall be checked for tightness; moisture and non-condensables shall be removed before charging the system with refrigerant. 7.1.2.6 Liquid line filter driers shall be provided on all installations of equipment types 6, 9, and 10 to ensure a dry and clean system. Such filter driers shall be chosen to ensure that the size and desiccant material are appropriate for the equipment. 7.1.2.7 Purging with inert gas is required during brazing to prevent oxidation, which can cause plugged driers, filters, strainers, dirty oil, and compressor failure. 7.2 Field Leak Testing. Equipment Types 6, 8, 9, and 10 shall be leak tested per Section 6.2.1 as an equipment type 8 to ensure system integrity and minimize refrigerant leakage. Informative Note: See Annex A for recommended procedures. 7.3 Field Evacuation. After it is determined that there are no refrigerant leaks, Equipment Types 6, 8, 9, and 10 shall be evacuated to 500 microns or less and held until long enough to remove moisture. 7.4 Field Charging


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7.4.1 Charging. After it is determined that the system does not leak, it shall be charged with refrigerant following the procedure specified in the equipment manufacturers instructions. If the system uses a medium or high pressure refrigerant and is not to be fully charged immediately after evacuation, it shall be placed under positive pressure with a partial charge of the refrigerant to be used in the system. 7.4.2 Backflow Prevention. When connected for charging, refrigerant containers shall not be connected to a system at a higher pressure or to hydraulic legs where the pressure is sufficient to cause a backflow of refrigerant into the container. 7.5 Refrigerant Charging Log For Equipment Types 6, 7, 8, 9, and 10, the owner shall keep a record of the following:

Identification of the installing contractor Identification of the facility The full charge Refrigerant type and designation under ASHRAE Standard 3417 Lubricant type and amount added. Lubricant additives type and amount added

This information shall be recorded in a clear, legible condition. This log shall be used to contain the records of future maintenance actions described in Section 8.4.1. 7.6 Water-chilling Machines: During installation, the installer or operator shall provide and install controls to prevent fluids from freezing in water-chilling machines when they are not in operation.

8. SERVICE/OPERATION/MAINTENANCE/DECOMMISSIONING This section explains the requirements for operating, servicing and maintaining, and decommissioning air-conditioning and refrigerating systems and equipment. 8.1 Servicing. Servicing of air-conditioning and refrigerating systems shall be undertaken only by properly trained personnel. In the US and in some other countries, regulations require that personnel engaged in refrigerant handling be certified. Reference shall be made to the manufacturer's operating and maintenance instructions for recommended service procedures. Informative Note: Generally recommended practices and procedures can be found in Annex A; however, they are not required for compliance with this standard. 8.1.1 Incorrect Uses. Halogenated refrigerants shall not be used for the purpose of cleaning debris and dirt from air-cooled condenser coils, cooling coils, or similar equipment. 8.1.2 When to Leak Check. Loss of capacity, loss of efficiency, unusual operating conditions or traces of oil may be evidence of a refrigerant leak. If a refrigerant leak is suspected, refrigerant shall not be added without leak-checking the system. Refer to the U.S. Code of Federal Regulations, 40 CFR, Part 82.15611 for the criteria for repairing leaks. Special attention shall be given to all joints, gaskets, control bellows, and shaft seals. These items shall be thoroughly leak-tested after servicing. 8.1.3 Pressurization. Equipment Types 5 10 that use a refrigerant and that have the potential to be in a vacuum at normal room temperatures shall be put under positive pressure before leak testing. The low-side pressure increase could typically be from the addition of heat to the system, or injecting another vapor into the system. Extreme care shall be taken to prevent excessive pressure buildup and the subsequent refrigerant release into the atmosphere. Automatic pressurization processes shall be provided with controls to prevent over-pressurization. Manual pressurization processes shall be continuously monitored to prevent over pressurization. A pressure increase shall be accomplished by the addition of dry nitrogen only if the system employs a refrigerant recovery type purge device. Air or oxygen shall not be


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used for pressurization. Refrigerant and oil in the presence of pressurized air or oxygen can cause uncontrolled combustion. 8.1.4 Leak Sources. Valve stem glands, blanks over gauge ports, and service valve seal caps shall be replaced and tightened after removal for servicing and shall be thoroughly leak-tested after servicing. 8.1.5 Oil Removal. Before oil is removed from a compressor, the oil sump heater (if so equipped) shall be turned on and the oil sump refrigerant pressure shall be repetitively reduced by safe and correct recovery, or by pump down to 0 psig or below until such time that the oil sump pressure does not noticeably rise within 10 minutes of terminating the pressure reduction. 8.1.6 Repairs. For non-major repairs, refrigerant pressure shall be reduced to less than 0 psig by safe and correct recovery or pumpdown to prevent refrigerant loss from a system or its components when opened to atmosphere during maintenance of non-major repairs. Non-major repairs are those that do not involve removing the compressor, condenser, evaporator, or auxiliary heat exchanger coil(s). See the U.S.E.P.A. regulations at 40 CFR 82.156(a) 11 for the provisions governing major and non-major repairs to air-conditioning and refrigerating equipment. For major repairs, the serviced part of the system shall be isolated to minimize the loss of refrigerant during recovery. If isolation is not possible, the total refrigerant charge shall be pumped into the system receiver or recovered. Refer to 40 CFR, Part 82.15, 11 for evacuation requirements. Only then shall repair be undertaken. Under no circumstances shall the refrigerant be discharged to the atmosphere. 8.1.7 Charging of Systems during Service. When connected for charging, refrigerant containers shall not be connected to a system at a higher pressure or to hydraulic legs where the pressure is sufficient to cause a backflow of refrigerant into the container. 8.2 Cleaning a Refrigerant System After a Mechanical Failure, Contamination, or Motor Burnout If the refrigerant is to be removed from the system due to contamination, the refrigerant shall be recycled, reclaimed, or disposed of in accordance with EPA regulations. In no case shall the refrigerant be vented to the atmosphere. After reassembly, the system shall be evacuated, leak-tested, and charged in accordance with Section 7. 8.3 System Operation and Maintenance. HVAC systems shall have maintenance programs based on manufacturers recommendations, ANSI/ACCA 4, Maintenance of Residential HVAC Systems,12 ANSI/ASHRAE/ACCA 180, Standard Practice for Inspection and Maintenance of Commercial Building HVAC Systems,13 and industry recognized practices followed to reduce and prevent refrigerant releases. Informative Note: Recommended practices and procedures may be found in Annex A6; however, they are not required for compliance with this standard. 8.3.1. Maintenance Program. Equipment types 7, 8, and 10 shall have a preventative maintenance program that shall include inspections for evidence of refrigerant leaks. The maintenance plan shall be reviewed and updated annually. (a) The maintenance program shall be planned and predictive. (b) This inspection shall include both a visual inspection of the system, a review of any equipment operating logs, and verification of the refrigerant charge containment. (c) he program shall verify the function of the refrigerant leak monitoring and or charge monitoring system. Informative Note: Recommended practices and procedures may be found in Annex A6; however, they are not required for compliance with this standard. 8.4 Actions after Refrigerant Monitoring Alarm. Owners of HVACR systems that are equipped with leak detection monitoring, or refrigerant charge monitoring, or both, and that provide an alert when a potential refrigerant release has occurred shall not add refrigerant without leak-checking the system. The owner shall follow the criteria in U.S. Code of Federal Regulations, 40 CFR, Part 82.156,11 for repairing leaks. A refrigerant charging log as described in Section 7.5 shall be maintained. Informative Note: Generally, recommended practices and procedures for system monitoring may be found in Annex A; however, they are not required for compliance with this standard.


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8.4.1 Refrigerant Charging Log: For Equipment Types 7, 8, and 10, the owner shall maintain the log initiated in Section 7.5 and record of the following regarding any refrigerant leaks: Identification of the servicing technician The date a leak was discovered The location of the leaks to the extent determined to date Any leak repair work that has been completed thus far and the date the work was completed. Any measure taken to assess whether the leak was effectively repaired, the date of such assessment, and the results or conclusion Retrofits of the system with alternative refrigerants, the type of alternative refrigerant used, and the date of any such retrofit shall be recorded in the log. 8.5 Refrigerant/Lubricant Change-Out. Seals, gaskets, and valve packing shall be replaced in accordance with manufacturers instructions when changing from one refrigerant or lubricant to another. Reusing these materials has a high potential to result in leaks.

9. REFRIGERANT RECOVERY, REUSE, AND DISPOSAL This section gives the requirements for recovery, reuse, and disposal of refrigerant from refrigerating and air-conditioning equipment and systems. 9.1 General. Refrigerant used in any type of air-conditioning or refrigerating equipment shall be recovered and reused in the owners equipment, or it shall be shipped in proper containers to a reclamation or destruction facility whenever it is removed from equipment. It shall not be released to the atmosphere. Informative Note: Recommendations on the disposition of recovered refrigerant may be found in Annex A; however, they are not required for compliance with this standard. 9.2 Refrigerant Transfer, Transport, and Storage. Refrigerant withdrawn from a system or equipment shall be transferred to an appropriate pressure vessel for storage on site or transport to another site. Disposable refrigerant containers, including those identified as complying with the United States Department of Transportation DOT Specification 39,14 shall not be reused under any circumstances. 9.2.1 Safety. Appropriate safety practices shall be followed when transferring refrigerant from equipment or a system to a refrigerant container, when transporting refrigerant from one location to another, and when storing refrigerant (see Section 10). 9.2.1.1 Color-Coded Containers. Refrigerant shall be transferred to a container that has been identified by the color code for the refrigerant, as specified in AHRI Guideline K-2009, Containers for Recovered Fluorocarbon Refrigerants,15 and shall comply with appropriate DOT regulations for refillable containers. 14 9.2.1.2 Overfilling Prohibited. Refrigerant containers shall not be overfilled (see Section 10.2.4). The design maximum working pressure of the container shall not be exceeded, even temporarily, during any filling operation. Informative Note: Refrigerant-oil mixtures have a lower density than refrigerant alone; the container capacity will therefore be reduced for a refrigerant-oil mixture. 9.2.1.3 Mixing of Refrigerants Prohibited. Refrigerant shall not be placed in any container that contains a different or an unknown refrigerant. In no case shall a refrigerant already in a container be vented to the atmosphere. 9.2.2 Transport. Refrigerant shall be transported from one location to another in a safe manner. All requirements of relevant laws, including registration and obtaining permits, shall be observed. See, for example, DOT regulations in Title 49 CFR Part 178. 14 9.2.3 Storage. Refrigerant shall be stored in a safe manner in accordance with local laws and regulations. The storage site shall be dry and protected from weather to minimize corrosion of refrigerant containers. Containers (except those


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designed for outside storage of refrigerant) shall not be stored in direct sunlight (see also Section 10.2) or in close proximity to a heat source. 9.3 Disposal. If recovered refrigerant is not intended to be reused, recycled or reclaimed, it shall be destroyed in an approved facility. 10. HANDLING AND STORAGE OF REFRIGERANTS This section specifies how to comply with this standard in the handling and storage of halogenated refrigerants. 10.1 System Connections. Charging lines shall be made of materials that are compatible with the refrigerant. 10.2 Storage 10.2.1 Refrigerant Container Design. Refrigerant containers shall be constructed to meet DOT packaging requirements as required by Title 49 CFR Part 178.14 10.2.2 Containers for Recovered Refrigerants. Pressure cylinders for recovered non-flammable fluorocarbon refrigerants shall be of refillable design, which includes a properly set relief valve and a valve guard (49 CFR 178). 14 10.2.3 Non-Reusable Containers Prohibited for Recovered Refrigerants. Previously filled DOT Specification 3914 non-reusable (non-refillable) cylinders shall not be used for recovery and transportation of recovered refrigerants. Informative Note: Title 49 CFR 178.6514 describes substantial fines and possible imprisonment for transportation of refilled DOT 39 cylinders. 10.2.4 Maximum Mass for Medium and High-Pressure Refrigerants. In filling high-pressure and medium-pressure refrigerant containers, the maximum allowable gross mass shall be equal to the sum of the cylinder tare mass plus 80% of the water capacity mass multiplied by the specific gravity of the refrigerant recovered at 77 F [25 C]. Informative Note:Further recommendations on containers and proper storage of recovered refrigerants may be found in AHRI Guideline K, Containers for Recovered Fluorocarbon Refrigerants.15 10.2.5 Dedicated Containers. For reasons of safety, and to avoid cross-contamination or misidentification of refrigerants, containers shall only be filled with the refrigerant indicated on the container. 10.2.6 Vapor Space for Low-Pressure Refrigerants. Drums that originally contained low-pressure refrigerants such as R-11, R-123, or refrigerant R-113 (excluding those originally used for cleaning agents), if used again for the same recovered low pressure refrigerant, shall be filled to allow a vapor space that is at least equal to 10% of the drum height.


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11. NORMATIVE REFERENCES References required for compliance with this standard are listed below. Informative references are listed in Annex C.

1. ANSI/ASHRAE Standard 15-2010, Safety Standard for Refrigeration Systems. 2007. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, Ga.

2. AHRI 580-2009, Performance of Non-Condensable Gas Purge Equipment for Use with Low Pressure Centrifugal Chillers.Air-Conditioning, Heating and Refrigeration Institute, Arlington, Va.

3. ASTM D642-2000 (RA2005), Standard Test Method for Determining Compressive Resistance of Shipping Containers, Components, and Unit Loads. ASTM International, West Conshohcoken, Pa.

4. ASTM D4577-2005, Standard Test Method for Compression Resistance of a Container Under Constant Load. West Conshohcoken, Pa.

5. ASTM D999-2008, Standard Test Methods for Vibration Testing of Shipping Containers. West Conshohcoken, Pa.

6.. ASTM D4728-2006, Standard Test Method for Random Vibration Testing of Shipping Containers. West Conshohcoken, Pa.

7. ASTM D6055-1996 (RA 2007) Standard Test Methods for Mechanical Handling of Unitized Loads and Large Shipping Cases and Crates. West Conshohcoken, Pa.

8. ASTM D6179-2007, Standard Test Methods for Rough Handling of Unitized Loads and Large Shipping Cases and Crates. West Conshohcoken, Pa.

9. ASTM D880-1992 (RA 2008), Standard Test Method for Impact Testing for Shipping Containers and Systems. West Conshohcoken, Pa.

10. ASTM D5276-1998 (RA 2009), Standard Test Method for Impact Testing for Shipping Containers and Systems. West Conshohcoken, Pa.

11. U.S. Code of Federal Regulations, 40 CFR, Part 82, Subpart F.

12. ANSI/ACCA 4, Maintenance of Residential HVAC Systems.

13. ANSI/ASHRAE/ACCA Standard 180-2008, Standard Practice for Inspection and Maintenance of Commercial Building HVAC Systems. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, Ga

14. DOT 39, Department of Transportation, Code of Federal Regulations, 49 CFR, Part 178, Subpart C.

15. AHRI Guideline K-2009, Containers for Recovered Fluorocarbon Refrigerants. Air-Conditioning, Heating and Refrigeration Institute, Arlington, Va.

16. UL 1995 (3rd Edition, 2/18/05), Heating and Cooling Equipment. Underwriters Laboratories.

17. ANSI/ASHRAE Standard 34-2010, Designation and Safety Classification of Refrigerants. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, Ga.


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(This annex is not part of this standard. It is merely informative and does not contain requirements necessary for conformance to the standard. It has not been processed according to the ANSI requirements for a standard and may contain material that has not been subject to public review or a consensus process. Unresolved objectors on informative material are not offered the right to appeal at ASHRAE or ANSI.) INFORMATIVE ANNEX A RECOMMENDED PROCEDURES AND PRACTICES A1 INTRODUCTION This annex contains practices and procedures that are recommended but not required for compliance with this standard. A2 RECOMMENDED DESIGN PRACTICES A2.1 Compressors A2.1.1 Shaft Seals. Shaft-seal designs that do not rely on the commonly used carbon faces are available. Double-faced seals and single-carbon seals with improved features to keep the carbon in a wet state have been found to be effective and may be used. The design and installation of the shaft-seal assembly should minimize external oil loss and prevent direct refrigerant loss. Lack of lubrication during shutdown periods can cause the mating faces of the seal to dry out and adhere together. On large systems, a separate oil pump to lubricate the seal prior to starting the compressor is recommended. Open compressors typically have carbon-face seals that require positive pressure in order to function properly. Since these are not two-way seals, leakage may occur during evacuation. To prevent leakage, temporary sealing measures such as shaft caps or clay-like weather stripping around the protrusion of the shaft should be used. The motor-compressor alignment is critical in limiting refrigerant leakage and is affected by the style of the coupling and the speed and power of the motor. Refrigeration machinery requires stringent alignment to accommodate thermal growth over the load and temperature ranges. It is recommended that a tool utilizing laser alignment technology be used. If the motor or compressor is removed and replaced in the field, it is best practice to utilize this type of alignment tool. At a minimum, it is recommended that a tool utilizing laser alignment technology be used. If the motor or compressor is removed and replaced in the field, it is best practice to utilize this type of alignment tool. Shutdown and start-up procedures should ensure that oil is present to wet the seal faces. It may be necessary to run the oil pump and rotate the shaft periodically during long shutdown periods. If this is not possible, the seals should be inspected and lubricated before starting the system. A2.1.2 Vibration. Vibrations from gas pulses are best handled by a muffler placed as close to the compressor as possible. For those compressors that are spring-mounted, vibration elimination should be provided in the suction and discharge lines. When piping vibration eliminators are used, they should be rated for the design pressure used and they should be parallel with the shaft of the compressor and anchored firmly at the upstream end in the suction line and the downstream end in the discharge line. A2.2 Condensers and Evaporators A2.2.1 Air-Cooled Condensers and Evaporators A2.2.1.1 Excessive vibration from compressors or other equipment can cause tube failure. These effects should be considered.


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A2.2.1.2 Construction materials and methods of design should be selected to preclude emissions of refrigerant as a result of release during normal operation. For known corrosive environments (e.g; a service deli case where food items are being refrigerated or a coastal environment where corrosion is eminent) the coil must have an adequate tubing thickness or coating or other fin material to ensure adequate life of the heat exchanger. A2.2.1.3 Condensers and evaporators should be designed to keep the refrigerant volume (charge) as small as possible. A2.2.1.4 Air-cooled condensers and evaporators should be constructed with the fewest practicable number of joints and return bends. Brazing is the preferred method of joining (see also Section 4.5.1). A2.2.2 Liquid-Cooled Condensers and Evaporators A2.2.2.1 Excessive vibration can cause failure of shell-and-tube heat exchangers. Vibration from any of several sources can cause tube failure: (a) The boiling action in flooded evaporators can cause vibration at the natural frequency of the tubes, creating excessive wear at tube supports and possible failure. This problem can be avoided with tube supports that are properly spaced and sized. (b) Excessive fluid velocity in condensers and evaporators can set up vibrations that will cause premature tube failure. Precautions similar to those described above can minimize the problem. A2.2.2.2 Excessive fluid velocity in water-cooled condensers and evaporators can lead to premature failure by erosion. As velocities increase, the potential for premature failure increases as the square of the velocity. Care must be taken that design fluid velocities are within good practice for the material selected. Tube blockage, can result in increased velocities above design for normal flow through the heat exchanger. The potential for damage will be reduced by limiting velocities. A2.2.2.3 In applications where condenser fluid flows inside the tubing, fouling can lead to premature tube failure. Proper filtration can reduce erosion caused by foreign particles in the fluid. Proper chemical treatment can minimize the effects of corrosive elements in the fluid. A2.2.2.4 Seawater-cooled systems are especially susceptible to corrosion, as are some systems using waters containing traces of ammonia or microbiological organisms. These contaminants will attack the tubes and may also attack tube sheets and heat-exchanger heads leading to leakage. Facilities for routine flushing and inspection are advisable. Special linings and special tube materials may be required to minimize attack on these surfaces. A2.2.3 Evaporative Condensers A2.2.3.1 Proper water treatment can minimize the effects of corrosive elements in the evaporative fluid. A2.3 Piping, Tubing, and Connections Strainers, filters, and driers should be utilized to control moisture and capture solid contaminants, which will minimize damage to moving parts and avoid plugging of refrigerant circuits caused by contaminants in the system. These components should be isolated with valves (or pump-out capability provided) to permit quick recovery of refrigerant before component servicing and to reduce the potential for excessive refrigerant loss. Supports and bimetal transition joints should be designed to guard against electrolytic corrosion. A2.4 Access and Isolation Valves Access valves should be located where pressure readings will be taken. Adequate isolation of system components such as gauges, operating controls, and major components (compressors, heat exchangers, expansion devices, receivers, and accumulators) should be provided to minimize refrigerant loss during servicing or replacement in accordance with ANSI/ASHRAE Standard 15-2010, Safety Standard forRefrigeration Systems. Valves not having an internal stem diaphragm should be provided with seal caps to fit over the stem (if so equipped) in order to minimize leak sources. Seal caps should be tightened metal-to-metal seal type or should have equally effective long term sealing capability and should be attached to the valve body by a strap or chain to avoid losing them in service. A2.5 Relief Devices


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A2.5.1 separate relief devices may be provided for the high and low sides; however, high-side, pressure-relief devices may be piped so as to discharge into the low side of the system provided that (a) they are of a type not appreciably affected by back pressure and that (b) the low side is equipped with a pressure-relief device of sufficient capacity as specified in ANSI/ASHRAE Standard 15-2007, Safety Standard for Refrigeration Systems, to protect all connected vessels, compressors, and pumps subjected to excess pressure simultaneously. In centrifugal systems where the condenser cannot be isolated from the evaporator, a single pressure-relief device will suffice to protect the system in accordance with ANSI/ASHRAE Standard 15-2007, Safety Standard for Refrigeration Systems. A2.5.2 Where a relief valve is used, a rupture disc should be installed upstream of the valve to protect the valve from corrosion or inadvertent release. An indicator should be installed between the rupture disc and the relief valve to indicate that the disc has ruptured. The rupture disc should be a non-fragmenting type. Once the rupture disc has burst, it should be replaced as soon as possible. It may be necessary to remove the remaining refrigerant charge before replacing the disc. Where a rupture disk is used as the sole relief device, a relief valve is not required downstream, and the use of a non-fragmenting rupture disk is not required. Note: When pressure-relief devices are installed in series, provisions of Section VIII of the ASME Unfired Pressure Vessel Code should be observed. A2.6 Marking and Instruction The manufacturer should document for the user the refrigerant name, charging quantity, and needed instructions of equipment installation, testing, operation, maintenance, repair, and disposal. A2.7 Type 4 -Specific Topics: For factory-sealed systems, soldering, epoxy joining, and any other method demonstrated to maintain the hermetic nature of the system is acceptable as an alternative to brazing. A2.8 Type 5, 6, 7 -Systems-Specific Topics A2.8.1 Compressors. Suction and discharge fittings, whether mechanical or brazed joints, should be easily accessible for the service person. This will help to ensure a leak-free installation if the compressor fails and must be replaced. A2.8.2 Air-Cooled Condensers and Evaporators. Some commercially available silicone marine sealants have proven effective for protecting copper-aluminum joints from electrolytic corrosion. A2.8.3 Piping and Connections A2.8.3.1 Brazing is the preferred method of joining pipe to fittings, valves, and other components. A2.8.3.2 It is recommended that driers have a hermetic shell and braze fittings; however, the shell and fittings, whether brazed or mechanical, should be easily accessible for the service person if the drier needs to be replaced. A2.8.3.3 Pre-charged line sets are the preferred method of connecting HFC-based split systems. EPA regulations prohibit the sale of line sets pre-charged with HCFC-22. Field-installed lines requiring brazing, evacuation, and charging introduce more risk of release. If pre-charged line sets are provided for connecting the indoor and outdoor units of split systems, an adequate array of choices is recommended in order to allow proper line selection. This will facilitate better control of cleanliness, minimize use of fittings, and help ensure proper line sizing for oil return and charge control. A2.8.4 Valves A2.8.4.1 Due to temperature excursions while in heating-cycle duty and cooling-cycle duty, nonmetallic O-ring or gasket seals beneath a thumb-tightened cap tend to vulcanize or set with time and temperature, allowing refrigerant that seeps past the self-closing stems to escape the system. Metal-to-metal-type seal caps will help minimize this leakage. Adequate instructions for proper tightening of the access valve caps should be provided.


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A2.8.4.2 Expansion valves, if used in a unitary system, should be of the type that has superheat preset at the factory, thus eliminating mechanical joint s that accommodate a superheat stem. The body and element should be hermetic with brazed fittings. A2.8.4.3 Where possible, check valves, reversing valves, and solenoid valves should be brazed into the system at the factory. A2.9 Type 7 and 8 Equipment-Specific Topics A2.9.2 Prevention-of-Vacuum Systems and Leak-Test Pressurization Systems. Low-pressure systems can develop a vacuum during idle periods, causing non-condensable infiltration into the system. A prevention-of-vacuum system controls refrigerant pressure by applying heat to the evaporator. This results in maintenance of a pressure equilibrium between the chiller and atmosphere when idle. As a result, neither air can infiltrate nor refrigerant escape through possible leak paths. Prevention-of-vacuum systems may also be used to pressurize low-pressure chillers for the purpose of leak testing. A3 PRODUCT DEVELOPMENT A3.1 Refrigerant Handling Refrigerant recovery/recycling systems are recommended in laboratories employing refrigerant. Laboratory recovery/recycling systems should be examined for leaks on a frequent (at least monthly) basis. A3.2 Vibration Tests Vibration testing should be done to identify packaging or tubing weaknesses that could cause leaks during shipment. A3.3 Storage Temporary and prototype systems should not be stored for more than six months while containing refrigerant. Temporary and prototype systems stored for more than six months should contain positive-pressure inert gas. A4 MANUFACTURE A4.1 Evacuation To remove moisture during the manufacture of new air-conditioning or refrigerating equipment, the unit should be purged with heated dry air (40F [40C] dew point). After purging, a deep vacuum evacuation, which involves a single extended evacuation of the unit, should be performed. Air and other noncondensable gases may be removed by deep evacuation. A4.2 Internal Cleanliness: Every effort should be made to ensure internal cleanliness of components and equipment. A4.3 Factory Leak Test A4.3.1 Leak Test Methods All factory leak test methods fall into one of two catagories: the leak rate measurement method (reveals the presence of a leak) or the leak location method (reveals the location of a known leak). Some common examples of these two methods being used in the HVAC industry are as follows:

A4.3.1.1 Leak Rate Measurement Methods A4.3.1.1.1 Pressure Decay A4.3.1.1.2 Vacuum Decay A4.3.1.1.3 Helium Inside-Out Vacuum Chamber Test (ASTM E493) A4.3.1.1.4 Helium Accumulation Test (Method B of ASTM E499) A4.3.1.1.5 Helium Hood Test (ASTM 1603)

A4.3.1.2 Leak Location Methods

A4.3.1.2.1 Bubble Test Immersion


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A4.3.1.2.2 Bubble Test Application of Liquid Film A4.3.1.2.3 Detector Probe Test (Method A of ASTM E499) A4.3.1.2.4 Tracer Probe Test (Method A of ASTM E498)

Leak rate measurement methods do not provide information on the number and location of individual leaks. Leak location methods alone can not give reliable assurance that no leaks exist or that tests have revealed all leaks that exist. Without prior assurance that leaks do exist, leak location test methods become arbitrary in application. Multiple sources for this often overlooked conclusion and resulting misapplication of leak location methods can be cited in the literature including:

ASTM E432, Paragraph 6.1. ASME Boiler & Pressure Vessel Code, Section V - Nondestructive Examination, Article 10 Leak

Testing, Paragraphs III-1010, IV-1010, and V-1010(a). ASNT Nondestructive Testing Handbook, Volume 1 Leak Testing, 3rd Edition, pages 20, 320, 345, 346,

348. In practice, preliminary leak testing is usually done first by a less sensitive means to permit the identification, location, and repair of gross leaks. Next the system or component is subjected to an overall leak rate measurement test to determine if it meets the leakage acceptance criterion. When the system or component fails to meet the leakage acceptance criterion, individual leak sites are identified through the use of a sensitive leak location test method and repaired. For final assurance that the system or component meets the leakage acceptance criterion, it is necessary to repeat the leak rate measurement test at the conclusion of the location and repair process. A4.3.2 Selection and Sensitivity of Leak Testing Methods (Note that statements below are based largely on ASTM E432 Standard Guide for Selection of a Leak Testing Method) The correct choice of a leak test methods optimizes sensitivity, cost, and reliability of the test. It is important to recognize that leak location should be attempted after the presence of a leak has been verified by a leakage measurement test. One approach to choosing a leak measurement method is to rank the various methods according to test system sensitivity. The various testing methods must be individually examined to determine their suitability for the particular system being tested. Only then can the appropriate method be chosen. It is important to distinguish between the sensitivity associated with the instrument employed to measure leakage and the sensitivity of the test methodology followed using the instrument. Test methods that are based on pressure change (pressure decay and vacuum decay) do not typically have sufficient sensitivity to meet the needs of components and systems used in HVAC applications (see Section 8.3.1 of Zero Leaks Limiting Emissions of Refrigerants published by ASHRAE).. The pressure change test methods are useful to verify that a component or system is free from gross leaks. In general, leakage measurement procedures suited to HVAC components and systems involve covering the whole of the suspected region with tracer gas, while establishing a pressure differential across the system by either pressurizing with a tracer gas or by evacuating the opposite side. The presence and concentration of tracer gas on the lower pressure side of the system are determined and then measured. A dynamic test method (like the vacuum chamber test) can be performed in a relatively short time. Static techniques (involving accumulation) can be employed to increase the test sensitivity while also increasing the time required for testing. Leakage measurement methods that evacuate the internals of the component or system (like the hood test) are not suitable for HVAC applications where the component or system is subjected to a positive pressure in operation. Leaks may temporarily plug due to moisture, lubricants, flux, etc. and go undetected when tested at the low differential pressure conditions typical of testing evacuated components or systems. Optimum leakage measurement methods suited to HVAC components and systems are vacuum chamber testing (as described in ASTM E493) and accumulation testing (as described in Method B of ASTM E499). These two methods are used in practice with a number of different tracer gases including Helium (pure or mixed with Nitrogen), refrigerant


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(pure or mixed with Nitrogen) and 5% Hydrogen / 95% Nitrogen. The resulting sensitivity of the leakage measurement test will depend on a number of design factors and operating parameters. For small components and systems (nominally 1m3 external volume) these two methods are capable of readily and realistically detecting tracer gas leakage equivalent to R-410A leakage of less than 1 oz/yr from 250 psig into atmosphere. For larger components and systems, the sensitivity that is readily and realistically attainable will be somewhat higher. A4.3.3 Leak Rate Measurement Methods

A4.3.3.1 Pressure Decay Typically this test consists of charging the system or component with a gas, closing a valve to isolate the gas supply, and monitoring the pressure inside the system or component. A decrease in pressure over time is indicative of a leak. If the internal free volume of the pressurized unit under test is known, the leak rate can be calculated by using the following formula:

Q = P V

t

where: Q = Leak Rate (atm-cc/sec) P = Pressure Change Inside the Part Under Test (atm) V = Internal Free Volume (cc) t = Time over which the P occurred (sec) The ultimate sensitivity of a pressure decay test is limited by the effects of temperature because changes in temperature result in corresponding changes in pressure. Calculations in the literature show that in regards to HVAC systems and components, pressure decay testing is suitable to insure that gross leaks do not exist. Pressure decay testing sensitivity is typically insufficient for HVAC systems and components (see Section 8.3.1 of Zero Leaks Limiting Emissions of Refrigerants published by ASHRAE). Advantages of the pressure decay test are

tests the system or component under positive pressure (most HVAC systems and components operate under positive pressure conditions)

requires relatively inexpensive hardware can be done at high pressure to simultaneously satisfy any proof pressure test requirements on the

assembly line easily automated simple to understand, requires minimal training of personnel also can serves as a simultaneous leak location test

Disadvantages of the pressure decay test are

internal free volume is often unknown and must be measured to get a quantifiable result tests at high pressure can pose a safety hazard to personnel suitable only for gross leak testing in most HVAC applications unacceptable leaks may take excessive amounts of time. this test procedure should not be used as a final test to ensure a leak free joint or assembly.

4.3.3.2 Vacuum Decay

Typically this test consists of evacuating the system or component with a vacuum pump, closing a valve to isolate the pump, and monitoring the pressure inside the system or component. An increase in pressure over time is indicative of a leak. If the internal free volume of the evacuated unit under test is know, the leak rate can be calculated by using the following formula:

Q = P V

t

where: Q = Leak Rate (atm-cc/sec) P = Pressure Change Inside the Part Under Test (atm)


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V = Internal Free Volume (cc) t = Time over which the P occurred (sec) The ultimate sensitivity of a vacuum decay test is limited by the effects of outgassing. Outgassing in the system or component causes the pressure to rise for reasons other than leakage and this inherent P can lead to false failures. (There are a number of sources of outgassing in HVAC systems and residual water is almost always present to some degree.) Calculations in the literature show that in regards to HVAC systems and components, vacuum decay testing is suitable to insure that gross leaks do not exist. Vacuum decay testing sensitivity is typically insufficient for HVAC systems and components (see Section 8.3.2 of Zero Leaks Limiting Emissions of Refrigerants published by ASHRAE). Advantages of the vacuum decay test are

requires relatively inexpensive hardware vacuum assists in sealing to the unit under test easily automated simple to understand, requires minimal training of personnel

Disadvantages of the vacuum decay test are

internal free volume is often unknown and must be measured to get a quantifiable result tests the system or component under vacuum (most HVAC systems and components operate under

positive pressure conditions) leaks may temporarily plug due to moisture, lubricants, flux, etc. and go undetected when tested at

low differential pressure conditions suitable only for gross leak testing in most HVAC applications leak location on the system or component while it is under vacuum can be problematic and often a

separate positive pressure test is required to locate the site of a gross leak

4.3.3.3 Helium Inside-Out Vacuum Chamber Test (ASTM E493) This test is referred to as an Inside-Out test because the tracer gas (Helium) is inside the system or component under test and it is detected on the outside of the unit under test when a leak is present. The test is performed with the unit under test inside a vacuum chamber which is coupled to a mass spectrometer leak detector. The unit under test can be filled with tracer gas prior to loading it into the chamber (referred to as a pre-charged test) or the unit can be filled with tracer gas while it is inside the chamber via a line that is connected to it through the chamber wall (referred to as a charge-in-chamber test). The output of the leak detector during the inside-out test of the unit is compared to the output registered by a calibrated leak at the same test conditions to determine if the unit satisfies the leakage acceptance criterion. Analogous inside-out vacuum chamber test methods can be employed with tracer gases other than Helium. Advantages of the inside-out vacuum chamber test are


sufficient sensitivity to meet the leak testing needs of most all HVAC systems and components chamber can serve as a safety guard for personnel when the charge-in-chamber technique is utilized easily automated

Disadvantages of the inside-out vacuum chamber test are

hardware is expensive relative to other leak rate measurement methods requires trained personnel for maintenance and troubleshooting presence of tracer gas in the ambient air (background) can be problematic

4.3.3.4 Helium Accumulation Test (Method B of ASTM E499)

In this test the system or component is pressurized with tracer gas (Helium) and it is held in a sealed enclosure. The air in the enclosure is well mixed with a fan over a period of time allowing any leakage to accumulate.


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When the necessary dwell time has elapsed, the air inside the enclosure is sampled with a mass spectrometer leak detector. By introducing a calibrated leak into the same volume for the same elapsed time, the leak detector output with the unit under test can be compared to the output registered by the calibrated leak to determine if the unit satisfies the leakage acceptance criterion. Analogous accumulation test methods can be employed with tracer gases other than Helium. Advantages of the Helium accumulation test are


sufficient sensitivity to meet the leak testing needs of most all HVAC systems and components can be attained

hardware cost is lower than chamber test easily automated

Disadvantages of the Helium accumulation test are

requires trained personnel for maintenance and troubleshooting presence of tracer gas in the ambient air (background) can be problematic dwell time necessary to accumulate sufficient tracer gas for reliable go-no-go test may be

unacceptable in a production line setting

4.3.3.5 Helium Hood Test (ASTM 1603) The test is performed with the unit under test inside a hood which is filled with Helium. The unit under test is evacuated and coupled to a mass spectrometer leak detector. This test is sometimes referred to as an Outside-In test because the tracer gas (Helium) is outside the system or component under test and it is detected on the inside of the unit under test when a leak is present. The output of the leak detector during the test of the unit is compared to the output registered by a calibrated leak at the same test conditions to determine if the unit satisfies the leakage acceptance criterion. Analogous hood test methods can be employed with tracer gases other than Helium. Advantages of the hood test are

sufficient sensitivity to meet the leak testing needs of most all HVAC systems and components hardware cost is lower than chamber test easily automated

Disadvantages of the hood test are

tests the system or component under vacuum (most HVAC systems and components operate under positive pressure conditions)

leaks may temporarily plug due to moisture, lubricants, flux, etc. and go undetected when tested at low differential pressure conditions

requires trained personnel for maintenance and troubleshooting presence of tracer gas in the ambient air (background) can be problematic

A4.3.4 Leak Location Methods

A4.3.4.1 Bubble Test Immersion In this simple test, the system or component is pressurized with tracer gas (typically air) and then immersed in a liquid bath (typically water) and an operator looks for bubbles. Bubbles may emerge from the unit under test at such a rapid rate that there is no question of the existence and location of a leak. When small leaks are to be located the unit under test must remain submerged long enough for any bubbles coming from crevices to have a chance to collect and rise. Although longer waiting periods theoretically should result in higher sensitivity, the sensitivity is limited when the rate of bubble evolution approaches the rate at which the gas is dissolving in the liquid. In addition to dwell time, test sensitivity is influenced by clarity of the liquid, lighting, proximity of the leak site to the operator, and a number of human factors.


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Advantages of the bubble immersion test are requires relatively inexpensive hardware tests the system or component under pressure (most HVAC systems and components operate under

positive pressure conditions) with proper safety guarding, testing can be done at high pressure to simultaneously satisfy any proof

pressure test requirements on the assembly line the entire pressurized component can often be examined simultaneously simple to understand, requires minimal training of personnel leaks at test fittings and can be effectively ignored by the operator and will not influence test

sensitivity Disadvantages of the bubble immersion test are

introduces water into the manufacturing process which can be problematic for subsequent dehydration operations in the HVAC industry

there are often housekeeping and safety issues associated with the immersion tank and dripping wet parts

human factors have a strong influence on test results, especially in the location of small leaks

4.3.4.2 Bubble Test Application of Liquid Film The liquid film application test technique can be used to locate leaks on any system or component on which a positive pressure differential exists across the wall. The test liquid is applied to the exterior surface (application by spray or brush is common) and the joint is examined for bubbles in the solution film. The area to be inspected should be positioned to allow the liquid to lie on the surface without dripping off.

Advantages of the liquid film application bubble test are

requires relatively inexpensive hardware tests the system or component under pressure (most HVAC systems and components operate under

positive pressure conditions) simple to understand, requires minimal training of personnel leaks at test fittings and can be effectively ignored by the operator and will not influence test

sensitivity Disadvantages of the liquid film application bubble test are

introduces water and soap into the manufacturing process which can be problematic for subsequent dehydration operations in the HVAC industry

human factors have a strong influence on test results, especially in the location of small leaks

4.3.4.3 Detector Probe Test (Method A of ASTM E499) In this test the system or component is pressurized with tracer gas and the detector is used to probe the external surfaces of the unit under test to locate leak sites. This test technique is commonly referred to as Helium sniffing or refrigerant sniffing where reference is made to the specific tracer gas in use. Factors that influence the sensitivity of the detector probe test include the speed at which the probe is moved, the distance between the surface of the part and the probe, and the orientation of the probe relative to the direction of the gas exiting the defect. When Helium is

std 147 2002r ppr2 (chair approved r1)

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