Appendix B: Hydronic Piping Systems

30PA R T30

H VA C E Q U AT I O N S , D ATA , A N D R U L E S O F T H U M B

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30.01 Hydronic Piping Systems

A. Table Notes: Hydronic Piping Systems—Copper, Steel, and Stainless Steel Pipe:

1. Maximum Recommended Pressure Drop: 4 Ft./100 Ft.2. Maximum Recommended Velocity (Occupied Areas): 8 Fps.3. Maximum Recommended Velocity (Unoccupied Areas, Shafts, Tunnels, etc.): 10 FPS.4. Standard steel pipe and Type L copper pipe are the most common pipe materials used

in HVAC applications.5. Tables are applicable to closed and open hydronic piping systems.6. Pipe Sizes 5″, 22″, 26″, 28″, 32″, and 34″ are not standard sizes and not readily available

in all locations.7. Types K, L, and M copper pipe are available in sizes through 12 inch.8. Standard and XS steel pipe are available in sizes through 96 inch.9. XXS steel pipe is available in sizes through 12 inch.

10. Schedule 40 steel pipe is available in sizes through 96 inch.11. Schedule 80 and 160 steel pipe are available in sizes through 24 inch.12. Schedule 5 and 10 stainless steel pipe are available in sizes through 24 inch.13. Standard and Schedule 40 steel pipe have the same dimensions and flow for 10 inch and

smaller.14. XS and Schedule 80 steel pipe have the same dimensions and flow for 8 inch and

smaller.15. XXS and Schedule 160 have no relationship for dimensions or flow.

Hydronic Piping Systems—Type K Copper Pipe

Appendix B: Hydronic Piping Systems 461

Hydronic Piping Systems—Type L Copper Pipe

Hydronic Piping Systems—Type M Copper Pipe

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Hydronic Piping Systems—Standard Steel Pipe

Appendix B: Hydronic Piping Systems 463

Hydronic Piping Systems—XS Steel Pipe

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Hydronic Piping Systems—XXS Steel Pipe

Appendix B: Hydronic Piping Systems 465

Hydronic Piping Systems—Schedule 40 Steel Pipe

Hydronic Piping Systems—Schedule 160 Steel Pipe

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Hydronic Piping Systems—Schedule 80 Steel Pipe

Appendix B: Hydronic Piping Systems 467

Hydronic Piping Systems—Schedule 5 Stainless Steel Pipe

Hydronic Piping Systems—Schedule 10 Stainless Steel Pipe

Bypass and Warming Valves

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Notes:1. Series A covers steam service for warming up before the main line is opened and for balancing

pressures where lines are of limited volume.2. Series B covers lines conveying gases or liquids where bypassing may facilitate the operation of the

main valve by balancing the pressures on both sides of the disc or discs thereof. The valves in thelarger sizes may be of the bolted on type.

Appendix B: Hydronic Piping Systems 469

Hydronic System Design Temperatures and Pressures

Notes:1. Safety: High temperature hydronic systems when operated at higher system temperatures and

higher system pressures will result in lower chance of water hammer and the damaging effects ofpipe leaks. These high temperature heating water systems are also safer than lower temperatureheating water systems because system leaks subcool to temperatures below scalding due to thesudden decrease in pressure and the production of water vapor.

2. The antiflash margin of 40°F. minimum is recommended for nitrogen or mechanically pressur-ized systems.

470 PART 30

30.02 Glycol Systems

Ethylene Glycol

Notes:1. Specific gravity with respect to water at 60°F.

Propylene Glycol

Notes:1. Specific gravity with respect to water at 60°F.

Appendix B: Hydronic Piping Systems 471

30.03 Air Conditioning (AC) Condensate Piping

A. AC Condensate Flow:

1. Range: 0.02–0.08 GPM/Ton2. Average: 0.04 GPM/Ton3. Unitary Packaged AC Equipment: 0.006 GPM/Ton4. Air Handling Units (100% outside Air): 0.100 GPM/1000 CFM5. Air Handling Units (50% Outdoor Air): 0.065 GPM/1000 CFM6. Air Handling Units (25% Outdoor Air): 0.048 GPM/1000 CFM7. Air Handling Units (15% Outdoor Air): 0.041 GPM/1000 CFM8. Air Handling Units (0% Outdoor Air): 0.030 GPM/1000 CFM

B. AC Condensate Pipe Sizing:

1. Minimum Pipe Sizes are given in the following table:

Air Conditioning Condensate Pipe Sizing

2. Pipe size shall not be smaller than drain pan outlet. Minimum size below grade andbelow ground floor shall be 21⁄2″ (4″ Allegheny Co., PA). Drain shall have slope of not lessthan 1⁄8″ per foot.

3. Some localities require AC condensate to be discharged to storm sewers, some requireAC condensate to be discharged to sanitary sewers, and some permit AC condensate tobe discharged to either storm or sanitary sewers. Verify pipe sizing and dischargerequirements with local authorities and codes.