Chapter 12 Hydronic piping
Section 1201 General
1201.1 Scope.
The provisions of this chapter shall govern the construction, installation, alteration and repair of hydronic piping systems. This chapter shall apply to hydronic piping systems that are part of heating, ventilation and air-conditioning systems. Such piping systems shall include steam, hot water, radiant heating, radiant cooling, chilled water, steam condensate, ground source heat pump loop systems, and snow- and ice-melting. Potable cold and hot water distribution systems shall be installed in accordance with the International Plumbing Code.
1201.2 Sizing.
Piping and piping system components for hydronic systems shall be sized for the demand of the system.
Section 1202 Material
1202.2 Used materials.
Reused pipe, fittings, valves or other materials shall be clean and free from foreign materials and shall be approved by the code official for reuse.
1202.3 Material rating.
Materials shall be rated for the operating temperature and pressure of the hydronic system. Materials shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards.
Hydronic pipe shall conform to the standards listed in Table 1202.4. The exterior of the pipe shall be protected from corrosion and degradation.
MATERIAL | |
Acrylonitrile butadiene styrene (ABS) plastic pipe | |
Chlorinated polyvinyl chloride (CPVC) plastic pipe | |
Chlorinated polyvinyl chloride/aluminum/chlorinated polyvinyl chloride (CPVC/AL/CPVC) | |
Copper or copper-alloy pipe | |
Copper or copper-alloy tube (Type K, L or M) | |
Cross-linked polyethylene/aluminum/cross-linked polyethylene (PEX-AL-PEX) pressure pipe | |
Cross-linked polyethylene (PEX) tubing | |
Ductile iron pipe | |
➡ | |
Polyethylene/aluminum/polyethylene (PE-AL-PE) pressure pipe | |
Polypropylene (PP) plastic pipe | |
Polyvinyl chloride (PVC) plastic pipe | |
Raised temperature polyethylene (PE-RT) | |
Stainless steel pipe | |
Stainless steel tubing | |
Steel pipe | |
Steel tubing |
1202.5 Pipe fittings.
Hydronic pipe fittings shall be approved for installation with the piping materials to be installed, and shall conform to the respective pipe standards or to the standards listed in Table 1202.5.
1202.6 Valves.
Valves shall be constructed of materials that are compatible with the type of piping material and fluids in the system. Valves shall be rated for the temperatures and pressures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration compensators.
Flexible connectors, expansion and vibration control devices and fittings shall be of an approved type.
Section 1203 Joints and Connections
1203.1 Approval.
Joints and connections shall be of an approved type. Joints and connections shall be tight for the pressure of the hydronic system.
1203.1.1 Joints between different piping materials.
Joints between different piping materials shall be made with approved adapter fittings.
1203.2 Preparation of pipe ends.
Pipe shall be cut square, reamed and chamfered, and shall be free from burrs and obstructions. Pipe ends shall have full-bore openings and shall not be undercut.
1203.3 Joint preparation and installation.
Where required by Sections 1203.4 through 1203.12, the preparation and installation of brazed, mechanical, soldered, solvent-cemented, threaded and welded joints shall comply with Sections 1203.3.1 through 1203.3.8.2.
1203.3.2 Mechanical joints.
Mechanical joints shall be installed in accordance with the manufacturer’s instructions.
1203.3.4 Solvent-cemented joints.
Joint surfaces shall be clean and free from moisture. An approved primer shall be applied to CPVC and PVC pipe-joint surfaces. Joints shall be made while the cement is wet. Solvent cement conforming to the following standards shall be applied to all joint surfaces:
- 1.
- 2.
- 3.
CPVC joints shall be made in accordance with ASTM D2846.
Exception: For CPVC pipe joint connections, a primer is not required where all of the following conditions apply:
- 1.
- 2.
The solvent cement is yellow or green in color.
- 3.
The solvent cement is used only for joining 1/2-inch (12.7 mm) through 2-inch (51 mm) diameter CPVC pipe and fittings.
- 4.
1203.3.5 Threaded joints.
Threads shall conform to ASME B1.20.1. Schedule 80 or heavier plastic pipe shall be threaded with dies specifically designed for plastic pipe. Thread lubricant, pipe-joint compound or tape shall be applied on the male threads only and shall be approved for application on the piping material.
1203.3.6 Welded joints.
Joint surfaces shall be cleaned by an approved procedure. Joints shall be welded with an approved filler metal.
1203.3.8 Mechanically formed tee fittings.
Mechanically extracted outlets shall have a height not less than three times the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance.
Branch tubes shall not restrict the flow in the run tube. A dimple/depth stop shall be formed in the branch tube to ensure that penetration into the outlet is of the correct depth. For inspection purposes, a second dimple shall be placed 1/4 inch (6.4 mm) above the first dimple. Dimples shall be aligned with the tube run.
1203.6 Copper or copper-alloy tubing.
Joints between copper or copper-alloy tubing or fittings shall be brazed, mechanical or soldered joints conforming to Section 1203.3, flared joints conforming to Section 1203.6.1, push-fit joints conforming to Section 1203.6.2 or press-connect joints conforming to Section 1203.6.3.
1203.6.1 Flared joints.
Flared joints shall be made by a tool designed for that operation.
1203.6.2 Push-fit joints.
Push-fit joints shall be installed in accordance with the manufacturer’s instructions.
1203.6.3 Press-connect joints.
Press-connect joints shall be installed in accordance with the manufacturer’s instructions.
1203.9 Cross-linked polyethylene (PEX) plastic tubing.
Joints between cross-linked polyethylene plastic tubing and fittings shall conform to Sections 1203.9.1 through 1203.9.3. Mechanical joints shall conform to Section 1203.3.
1203.9.1 Compression-type fittings.
Where compression-type fittings include inserts and ferrules or O-rings, the fittings shall be installed without omitting the inserts and ferrules or O-rings.
1203.9.2 Plastic-to-metal connections.
Soldering on the metal portion of the system shall be performed not less than 18 inches (457 mm) from a plastic-to-metal adapter in the same water line.
1203.15 Polypropylene (PP) plastic.
Joints between PP plastic pipe and fittings shall comply with Sections 1203.15.1 and 1203.15.2.
1203.15.1 Heat-fusion joints.
Heat-fusion joints for polypropylene (PP) pipe and tubing joints shall be installed with socket-type heat-fused polypropylene fittings, electro-fusion polypropylene fittings or by butt fusion. Joint surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in accordance with ASTM F2389.
1203.15.2 Mechanical and compression sleeve joints.
Mechanical and compression sleeve joints shall be installed in accordance with the manufacturer’s instructions.
1203.16 Raised temperature polyethylene (PE-RT) plastic tubing.
Joints between raised temperature polyethylene tubing and fittings shall conform to Sections 1203.16.1 through 1203.16.3. Mechanical joints shall conform to Section 1203.3.
1203.16.1 Compression-type fittings.
Where compression-type fittings include inserts and ferrules or O-rings, the fittings shall be installed without omitting the inserts and ferrules or O-rings.
1203.16.2 PE-RT-to-metal connections.
Solder joints in a metal pipe shall not occur within 18 inches (457 mm) of a transition from such metal pipe to PE-RT pipe.
1203.17 Polyethylene/aluminum/polyethylene (PE-AL-PE) pressure pipe.
Joints between polyethylene/aluminum/polyethylene pressure pipe and fittings shall conform to Sections 1203.17.1 and 1203.17.2. Mechanical joints shall comply with Section 1203.3.
1203.17.1 Compression-type fittings.
Where compression-type fittings include inserts and ferrules or O-rings, the fittings shall be installed without omitting the inserts and ferrules or O-rings.
1203.17.2 PE-AL-PE-to-metal connections.
Solder joints in a metal pipe shall not occur within 18 inches (457 mm) of a transition from such metal pipe to PE-AL-PE pipe.
1203.18 Cross-linked polyethylene/aluminum/cross-linked polyethylene (PEX-AL-PEX) pressure pipe.
Joints between cross-linked polyethylene/aluminum/cross-linked polyethylene pressure pipe and fittings shall conform to Sections 1203.18.1 and 1203.18.2. Mechanical joints shall comply with Section 1203.3.
1203.18.1 Compression-type fittings.
Where compression-type fittings include inserts and ferrules or O-rings, the fittings shall be installed without omitting the inserts and ferrules or O-rings.
1203.18.2 PEX-AL-PEX-to-metal connections.
Solder joints in a metal pipe shall not occur within 18 inches (457 mm) of a transition from such metal pipe to PEX-AL-PEX pipe.
Section 1204 Pipe Insulation
1204.1 Insulation characteristics.
Pipe insulation installed in buildings shall conform to the requirements of the International Energy Conservation Code, shall be tested in accordance with ASTM E84 or UL 723 using the specimen preparation and mounting procedures of ASTM E2231, and shall have a maximum flame spread index of 25 and a smoke-developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.3.
Exception: The maximum flame spread index and smoke-developed index shall not apply to one- and two-family dwellings.
Section 1205 Valves
1205.1 Where required.
Shutoff valves shall be installed in hydronic piping systems in the locations indicated in Sections 1205.1.1 through 1205.1.6. Access shall be provided to all full-open valves and shutoff valves.
1205.1.1 Heat exchangers.
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
1205.1.2 Central systems.
Shutoff valves shall be installed on the building supply and return of a central utility system.
1205.1.3 Pressure vessels.
Shutoff valves shall be installed on the connection to any pressure vessel.
1205.1.4 Pressure-reducing valves.
Shutoff valves shall be installed on both sides of a pressure-reducing valve.
1205.1.5 Equipment and appliances.
Shutoff valves shall be installed on connections to mechanical equipment and appliances. This requirement does not apply to components of a hydronic system such as pumps, air separators, metering devices and similar equipment.
1205.1.6 Expansion tanks.
Shutoff valves shall be installed at connections to nondiaphragm-type expansion tanks.
Section 1206 Piping Installation
1206.1 General.
Piping, valves, fittings and connections shall be installed in accordance with the conditions of approval.
1206.2 System drain down.
Hydronic piping systems shall be designed and installed to permit the system to be drained. Where the system drains to the plumbing drainage system, the installation shall conform to the requirements of the International Plumbing Code.
Exception: The buried portions of systems embedded underground or under floors.
1206.4 Pipe penetrations.
Openings for pipe penetrations in walls, floors or ceilings shall be larger than the penetrating pipe. Openings through concrete or masonry building elements shall be sleeved. The annular space surrounding pipe penetrations shall be protected in accordance with the International Building Code.
1206.5 Clearance to combustibles.
A pipe in a hydronic piping system in which the exterior temperature exceeds 250°F (121°C) shall have a minimum clearance of 1 inch (25 mm) to combustible materials.
1206.6 Contact with building material.
A hydronic piping system shall not be in direct contact with building materials that cause the piping material to degrade or corrode, or that interfere with the operation of the system.
1206.7 Water hammer.
The flow velocity of the hydronic piping system shall be controlled to reduce the possibility of water hammer. Where a quick-closing valve creates water hammer, an approved water-hammer arrestor shall be installed. The arrestor shall be located within a range as specified by the manufacturer of the quick-closing valve.
1206.8 Steam piping pitch.
Steam piping shall be installed to drain to the boiler or the steam trap. Steam systems shall not have drip pockets that reduce the capacity of the steam piping.
1206.9 Strains and stresses.
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. Provisions shall be made to protect piping from damage resulting from expansion, contraction and structural settlement. Piping shall be installed so as to avoid structural stresses or strains within building components.
1206.9.1 Flood hazard.
Piping located in a flood hazard area shall be capable of resisting hydrostatic and hydrodynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood elevation.
1206.11 Condensation.
Provisions shall be made to prevent the formation of condensation on the exterior of piping.
Section 1207 Transfer Fluid
1207.1 Flash point.
The flash point of transfer fluid in a hydronic piping system shall be not less than 50°F (28°C) above the maximum system operating temperature.
1207.2 Makeup water.
The transfer fluid shall be compatible with the makeup water supplied to the system.
Section 1208 Tests
1208.1 General.
Hydronic piping systems shall be tested hydrostatically at one and one-half times the maximum system design pressure, but not less than 100 psi (689 kPa). The duration of each test shall be not less than 15 minutes.
Exception: For PEX piping systems, testing with a compressed gas shall be an alternative to hydrostatic testing where compressed air or other gas pressure testing is specifically authorized by all of the manufacturers’ instructions for the PEX pipe and fitting products installed at the time the system is being tested, and compressed air or other gas testing is not otherwise prohibited by applicable codes, laws or regulations outside of this code.
Section 1209 Embedded Piping
1209.1 Materials.
Piping for heating panels shall be standard-weight steel pipe, Type L copper tubing or approved plastic pipe or tubing rated at 100 psi (689 kPa) at 180°F (82°C).
1209.2 Pressurizing during installation.
Piping to be embedded in concrete shall be pressure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure.
1209.3 Embedded joints.
Joints of pipe or tubing that are embedded in a portion of the building, such as concrete or plaster, shall be in accordance with the requirements of Sections 1209.3.1 through 1209.3.4.
1209.3.1 Steel pipe joints.
Steel pipe shall be welded by electrical arc or oxygen/acetylene method.
1209.4 Not embedded related piping.
Joints of other piping in cavities or running exposed shall be joined by approved methods in accordance with manufacturer’s installation instructions and related sections of this code.
1209.5 Insulation and thermal break required.
Radiant floor heating systems shall be provided with insulation and a thermal break in accordance with Sections 1209.5.1 and 1209.5.2. Insulation R-values for slab-on-grade and suspended floor installation shall be in accordance with the International Energy Conservation Code.
Exception: Insulation shall not be required in engineered systems where it can be demonstrated that the insulation will decrease the efficiency or have a negative effect on the installation.
1209.5.1 Thermal break required.
A thermal break shall be provided consisting of asphalt expansion joint materials or similar insulating materials at a point where a heated slab meets a foundation wall or other conductive slab.
1209.5.2 Insulation material marking.
Insulating materials utilized in radiant floor heating systems shall be installed such that the manufacturer’s R-value mark is readily observable upon inspection.
1209.6 Radiant tubing placement.
Hydronic tubing to be embedded for the purpose of radiant heating or cooling shall be installed in accordance with the manufacturer’s instructions and with the tube layout and spacing in accordance with the system design. Individual tubing circuit lengths shall be installed with a variance of not more than ±10 percent from the design.
1209.6.1 Radiant tubing circuit length.
The maximum circuit length of radiant tubing from a supply-and-return manifold shall not exceed the lengths specified by the system design or, in the absence of manufacturer’s specifications, the lengths specified in Table 1209.6.1.
NOMINAL TUBE SIZE | MAXIMUM CIRCUIT LENGTH (feet) |
1/4 | 125 |
5/16 | 200 |
3/8 | 250 |
1/2 | 300 |
5/8 | 400 |
3/4 | 500 |
1 | 750 |
For SI: 1 foot = 304.8 mm.
1209.6.2 Radiant tubing circuit tags.
Each individual radiant tubing circuit shall have a tag or label securely affixed to each manifold outlet to indicate the length of each circuit and the areas served.
1209.6.3 Radiant tubing drawings.
The radiant tubing drawings and design report shall be provided to the building owner or the designated representative of the building owner.
1209.7 Snow- and ice-melt tubing placement.
Hydronic tubing to be embedded for the purpose of snow- and ice-melt systems shall be installed in accordance with the manufacturer’s installation instructions and with the tube layout and spacing in accordance with the system design.
1209.7.1 Snow- and ice-melt tubing circuit length.
The maximum circuit length of snow- and ice-melt tubing from a supply-and-return manifold shall not exceed the lengths specified by the system design or, in the absence of manufacturer’s specifications, the lengths specified in Table 1209.7.1. Individual tubing circuit lengths shall be installed with a variance of not more than ±10 percent from the design.
NOMINAL TUBE SIZE | MAXIMUM CIRCUIT LENGTH (feet) |
1/2 | 140 |
5/8 | 250 |
3/4 | 325 |
1 | 475 |
For SI: 1 foot = 304.8 mm.
1209.7.2 Snow- and ice-melt tubing drawings.
The snow- and ice-melt tubing drawings and design report shall be provided to the building owner or the designated representative of the building owner.
Section 1210 Plastic Pipe Ground-Source Heat Pump Loop Systems
1210.1 Ground-source heat pump loop water piping.
Ground-source heat pump ground-loop piping and tubing material for water-based systems shall conform to the standards cited in this section.
1210.2 Used materials.
Reused pipe, fittings, valves, and other materials shall not be permitted in ground-source heat pump loop systems.
1210.3 Material rating.
Pipe and tubing shall be rated for the operating temperature and pressure of the ground-source heat pump loop system. Fittings shall be suitable for the pressure applications and recommended by the manufacturer for installation with the pipe and tubing material installed. Where used underground, materials shall be suitable for burial.
1210.4 Piping and tubing materials standards.
Ground-source heat pump ground-loop pipe and tubing shall conform to the standards listed in Table 1210.4.
1210.5 Fittings.
Ground-source heat pump pipe fittings shall be approved for installation with the piping materials to be installed, shall conform to the standards listed in Table 1210.5 and, if installed underground, shall be suitable for burial.
1210.6 Joints.
Joints and connections shall be of an approved type. Joints and connections shall be tight for the pressure of the ground-source loop system. Joints used underground shall be of an approved type for buried applications.
1210.6.1 Joints between different piping materials.
Joints between different piping materials shall be made with approved transition fittings.
1210.6.2 Preparation of pipe ends.
Pipe shall be cut square and be free from burrs and obstructions. Pipe ends shall have full-bore openings and shall be prepared in accordance with the manufacturer’s instructions.
1210.6.3 Joint preparation and installation.
Where required by Sections 1210.6.4 through 1210.6.8, the preparation and installation of mechanical and thermoplastic-welded joints shall comply with Sections 1210.6.3.1 and 1210.6.3.2.
1210.6.3.1 Mechanical joints.
Mechanical joints shall be installed in accordance with the manufacturer’s instructions.
1210.6.3.2 Thermoplastic-welded joints.
Joint surfaces for thermoplastic-welded joints shall be cleaned by an approved procedure. Joints shall be welded in accordance with the manufacturer’s instructions.
1210.6.5 Cross-linked polyethylene (PEX) plastic tubing.
Joints between cross-linked polyethylene plastic tubing and fittings shall comply with Sections 1210.6.5.1 and 1210.6.5.2. Mechanical joints shall comply with Section 1210.6.3.
1210.6.5.1 Compression-type fittings.
Where compression-type fittings include inserts and ferrules or O-rings, the fittings shall be installed without omitting the inserts and ferrules or O-rings.
1210.6.5.2 Plastic-to-metal connections.
Soldering on the metal portion of the system shall be performed not less than 18 inches (457 mm) from a plastic-to-metal adapter in the same water line.
1210.6.6 Polyethylene plastic pipe and tubing for ground-source heat pump loop systems.
Joints between polyethylene plastic pipe and tubing or fittings for ground-source heat pump loop systems shall be heat-fusion joints complying with Section 1210.6.6.1, electrofusion joints complying with Section 1210.6.6.2, or stab-type insertion joints complying with Section 1210.6.6.3.
1210.6.6.1 Heat-fusion joints.
Joints shall be of the socket-fusion, saddle-fusion or butt-fusion type, joined in accordance with ASTM D2657. Joint surfaces shall be clean and free from moisture. Joint surfaces shall be heated to melt temperatures and joined. The joint shall be undisturbed until cool. Fittings shall be manufactured in accordance with ASTM D2683 or ASTM D3261.
1210.6.6.2 Electrofusion joints.
Joints shall be of the electrofusion type. Joint surfaces shall be clean and free from moisture, and scoured to expose virgin resin. Joint surfaces shall be heated to melt temperatures for the period of time specified by the manufacturer. The joint shall be undisturbed until cool. Fittings shall be manufactured in accordance with ASTM F1055.
1210.6.7 Polypropylene (PP) plastic.
Joints between PP plastic pipe and fittings shall comply with Sections 1210.6.7.1 and 1210.6.7.2.
1210.6.7.1 Heat-fusion joints.
Heat-fusion joints for polypropylene (PP) pipe and tubing joints shall be installed with socket-type heat-fused polypropylene fittings, electrofusion polypropylene fittings or by butt fusion. Joint surfaces shall be clean and free from moisture. The joint shall be undisturbed until cool. Joints shall be made in accordance with ASTM F2389.
1210.6.7.2 Mechanical and compression sleeve joints.
Mechanical and compression sleeve joints shall be installed in accordance with the manufacturer’s instructions.
1210.6.8 Raised temperature polyethylene (PE-RT) plastic tubing.
Joints between raised temperature polyethylene tubing and fittings shall comply with Sections 1210.6.8.1 and 1210.6.8.2. Mechanical joints shall comply with Section 1210.6.3.
1210.6.8.1 Compression-type fittings.
Where compression-type fittings include inserts and ferrules or O-rings, the fittings shall be installed without omitting the inserts and ferrules or O-rings.
1210.6.8.2 PE-RT-to-metal connections.
Solder joints in a metal pipe shall not occur within 18 inches (457 mm) of a transition from such metal pipe to PE-RT pipe.
1210.7 Shutoff valves.
Shutoff valves shall be installed in ground-source loop piping systems in the locations indicated in Sections 1210.7.1 through 1210.7.7.
1210.7.1 Heat exchangers.
Shutoff valves shall be installed on the supply and return side of a heat exchanger.
1210.7.2 Central systems.
Shutoff valves shall be installed on the building supply and return of a central utility system.
1210.7.3 Pressure vessels.
Shutoff valves shall be installed on the connection to any pressure vessel.
1210.7.4 Pressure-reducing valves.
Shutoff valves shall be installed on both sides of a pressure-reducing valve.
1210.7.5 Equipment and appliances.
Shutoff valves shall be installed on connections to mechanical equipment and appliances. This requirement does not apply to components of a ground-source loop system such as pumps, air separators, metering devices, and similar equipment.
1210.7.6 Expansion tanks.
Shutoff valves shall be installed at connections to nondiaphragm-type expansion tanks.
1210.8 Installation.
Piping, valves, fittings and connections shall be installed in accordance with ANSI/CSA/IGSHPA C448 and the manufacturer’s instructions.
1210.8.2 Pipe penetrations.
Openings for pipe penetrations in walls, floors and ceilings shall be larger than the penetrating pipe. Openings through concrete or masonry building elements shall be sleeved. The annular space surrounding pipe penetrations shall be protected in accordance with the International Building Code.
1210.8.3 Clearance from combustibles.
A pipe in a ground-source heat pump piping system having an exterior surface temperature exceeding 250°F (121°C) shall have a minimum clearance of 1 inch (25 mm) from combustible materials.
1210.8.4 Contact with building material.
A ground-source heat pump ground-loop piping system shall not be in direct contact with building materials that cause the piping or fitting material to degrade or corrode, or that interfere with the operation of the system.
1210.8.5 Strains and stresses.
Piping shall be installed so as to prevent detrimental strains and stresses in the pipe. Provisions shall be made to protect piping from damage resulting from expansion, contraction and structural settlement. Piping shall be installed so as to avoid structural stresses or strains within building components.
1210.8.6 Flood hazard.
Piping located in a flood hazard area shall be capable of resisting hydrostatic and hydrodynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood elevation.
1210.8.8 Velocities.
Ground-source heat pump ground-loop systems shall be designed so that the flow velocities do not exceed the maximum flow velocity recommended by the pipe and fittings manufacturer and shall be controlled to reduce the possibility of water hammer.
1210.8.9 Labeling and marking.
Ground-source heat pump ground-loop system piping shall be marked with tape, metal tags or other method where it enters a building indicating “GROUND-SOURCE HEAT PUMP LOOP SYSTEM.” The marking shall indicate any antifreeze used in the system by name and concentration.
1210.8.10 Chemical compatibility.
Antifreeze and other materials used in the system shall be chemically compatible with the pipe, tubing, fittings and mechanical systems.
1210.9 Makeup water.
The transfer fluid shall be compatible with the makeup water supplied to the system.
1210.10 Tests.
Before connection header trenches are backfilled, the assembled loop system shall be pressure tested with water at 100 psi (689 kPa) for 15 minutes, in which time there shall not be observed leaks. Flow and pressure loss testing shall be performed and the actual flow rates and pressure drops shall be compared to the calculated design values. If actual flow rate or pressure drop values differ from calculated design values by more than 10 percent, the cause shall be identified and corrective action taken.
1210.11 Embedded piping.
Ground-source heat pump ground-loop piping to be embedded in concrete shall be pressure tested prior to pouring concrete. During pouring, the pipe shall be maintained at the proposed operating pressure.