PIPINGWithinindustry,pipingis a system ofpipes or network of pipesusedto conveyfluids(liquidsandgases) from one location to another over short distance.

The term here short distance does not refer to a fixed distance which can be classified in meters or inches but short distance here refers to Pipes used to connect minimum of 2 facilities/equipments confined in a specific region or area i.e. a process plant, refinery, fertilizer plants or a civil construction.

In a refining or a petrochemical complex, piping constitutes major expenditure of all design disciplines. Piping consume about 50% of design engineering man-hours, 35% of material cost of plant and about 30% of labour cost of a plant.

Theengineeringdiscipline of pipingdesignstudies the efficient transport of fluid by flow diagrams, model making, insulation & painting, piping material take-off, piping material control, instrument design & piping design itself.

Industrial process piping (and accompanying in-line components) can be manufactured fromwood,fiberglass,glass,steel,aluminium,plastic,copper, andconcrete.

The in-line components, known asfittings,flanges,valves, and other devices, typically sense and control thepressure,flow rateandtemperatureof the transmitted fluid, and usually are included in the field of Piping Design (or Piping Engineering).

Piping systems in detail are documented in piping and instrumentation diagrams(P&IDs) & General Arrangement Drawings (GADs). P&IDs & GADs are generated from Process Flow Diagrams (PFDs).

"Piping" sometimes refers to Piping Design, the detailed specification of the physical piping layout within a process plant or commercial building. In earlier days, this was sometimes calledDrafting,Technical drawing,Engineering Drawing, andDesignbut is today commonly performed by Designers who have learned to use automated Computer Aided Drawing / Computer Aided Design (CAD) software.

Ironically still piping design has been neglected in the school system. This is largely due to the fact that adequate complete & competitive textbooks are not available. No book or blog can teach a person to become a piping designer but it can teach the fundamental & how to apply them to become a designer.

Plumbingis a piping system that most people are familiar with, as it constitutes the form of fluid transportation that is used to provide potablewaterandfuelsto their homes and business. Plumbing pipes also remove waste in the form ofsewage, and allow venting of sewage gases to the outdoors.

Fire sprinklersystems also use piping, and may transport non-potable orpotable water, or other fire-suppression fluids.

Piping also has many other industrial applications, which are crucial for moving raw and semi-processed fluids for refining into more useful products.

Today Piping can be found any place one looks, from piping in automobile to complicated maze of piping in process plant.

Each year introduces new purpose for piping which creates demand for new and improved material specification. Some of the more exotic materials of construction areInconel,titanium,chrome-molyand various other steelalloys.

MODERN TECHNOLOGY IN PIPING

1.Pipe & Tube cleaningprocess. 2.Variable Spring for Pipe Support 3.FRP Wear pad 4.Snubbers 5.Sway Braces

ENGINEERING SUBFIELDS

Generally, Industrial Piping Engineering has three major subfields:Piping MaterialPiping DesignStress Analysis

Piping Material

Early pipes were constructed out of wooden logs that had a large hole bored lengthwise through the center.

Later wooden pipes were constructed with staves and hoops similar to woodenbarrelconstruction. Stave pipes have the advantage that they are easily transported as a compact pile of parts on a wagon and then assembled as a hollow structure at the job site. Wooden pipes were especially popular in mountain regions where transport of heavy iron or concrete pipes would have been difficult earlier.

Wooden pipes were easier to maintain than metal, because:-1.The wood did not expand or contract with temperature changes as much as metal and so consequently expansion joints and bends were not required.2.The thickness of wood afforded some insulating properties to the pipes which helped prevent freezing as compared to metal pipes.3.Electrolysis, that bugbear of many iron pipe systems, doesn't affect wood pipes at all, since wood is a much better electrical insulator.

In the Western United States whereredwoodwas used for pipe construction, it was found that redwood had "peculiar properties" that protected it from weathering, acids, insects, and fungus growths. Redwood pipes stayed smooth and clean indefinitely while iron pipe by comparison would rapidly begin to scale and corrode and could eventually plug itself up with the corrosion.

The types of materials actually used for pipes for piping willdepend upon whether the installation isunderground, outside buildings, undergroundwithin buildings, or aboveground withinbuildings. The availability of certain types ofdesired piping materials and fittings may alsogovern the type of pipe actually used.

Piping Materials are divided into 2 basic classes:-

A.Metallic1.Ferrousa.Cast Ironb.Carbon Steelc.Low Temperature Carbon Steeld.Stainless Steel etc.2.Non Ferrousa.Copperb.Brassc.Inconeld.Incoloye.Cupro Nickle etc.B.Non Metallic1.Glassa.Glass Reinforced Epoxyb.Tempered Glass etc.2.Ceramics3.Plasticsa.Poly Ethylene (PE)b.Cross Linked Poly Ethylene (PEX)c.Poly Vinyl Chloride (PVC)d.Chlorinated Poly Vinyl Chloride (CPVC)e.High Density Poly Ethylene (HDPE)f.Acrylonitrile Butadiene Styrene (ABS) etc.

Piping Design

Piping Design is a purely an engineering study as the main aim & objective for piping is to transport the fluid from one place to another with minimum effort loss in terms of mechanical & safely.

This topic will be discussed later on separately.

Stress analysis

Process piping and power piping are typically checked by Pipe Stress Engineers to verify that the routing, nozzle loads, hangers, and supports are properly placed and selected such that allowable pipe stress is not exceeded under different situation such as sustain, operating, pressure testing etc., as per theASMEB31, EN 13480 or any other applicable codes and standards.

It is necessary to evaluate the mechanical behaviour of the piping under regular loads (internal pressure and thermal stresses) as well under occasional and intermittent loading cases such as earthquake, high wind or special vibration, and water hammer.

This evaluation at earlier times was very tough & tiring whereas in modern days it is usually performed with the assistance of a specialized (finite element) pipestress analysiscomputer program such asCAESAR II,Triflex, ROHR2,CAEPIPEandAUTOPIPE.

In cryogenic pipe supports, most steel become more brittle as the temperature decreases from normal operating conditions, so it is necessary to know the temperature distribution for cryogenic conditions.

Steel structures will have areas of high stress that may be caused by sharp corners in the design, or inclusions in the material.

STANDARDS RELATED TO PIPING

There are certain standard codes that need to be followed while designing or manufacturing any piping system. Organizations that promulgate piping standards include:

ASME - TheAmerican Society of Mechanical Engineers- B31 seriesASME B31.1 Power piping (steam piping etc.)ASME B31.3 Process pipingASME B31.4 Hydrocarbons and Other Liquids pipingASME B31.5 Refrigeration piping and heat transfer componentsASME B31.8 Gas transmission and distribution piping systemsASME B31.9 Building services pipingASME B31.11 Slurry Transportation Piping SystemsASME B31.12 Hydrogen Piping and Pipelines

ASTM -American Society for Testing and Materials

API -American Petroleum Institute

EN 13480 - European metallic industrial piping codeEN 13480-1 Metallic industrial piping - Part 1: GeneralEN 13480-2 Metallic industrial piping - Part 2: MaterialsEN 13480-3 Metallic industrial piping - Part 3: Design and calculationEN 13480-4 Metallic industrial piping - Part 4: Fabrication and installationEN 13480-5 Metallic industrial piping - Part 5: Inspection and testingEN 13480-6 Metallic industrial piping - Part 6: Additional requirements for buried pipingPD TR 13480-7 Metallic industrial piping - Part 7: Guidance on the use of conformity assessment proceduresEN 13480-8 Metallic industrial piping - Part 8: Additional requirements for aluminium and aluminium alloy piping

EN 1993-4-3Eurocode3 Design of steel structures - Part 4-3: Pipelines

AWS -American Welding Society

AWWA -American Water Works Association

MSS Manufacturers' Standardization Society

ANSI -American National Standards Institute

NFPA -National Fire Protection Association

EJMA -Expansion Joint Manufacturers Association

Many countries have so far not developed their own standards for the design of piping System & hence one or more of the above standards are used for the designing purpose.