N.Y.C. Admin. Code § MC 1210: Section MC 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.

Table 1210.4 Ground-Source Loop Pipe

Material

Standard (see Chapter 15)

Chlorinated polyvinyl chloride (CPVC)

ASTM D 2846; ASTM F 441; ASTM F 442

Cross-linked polyethylene (PEX)

ASTM F 876; ASTM F 877; CSA B137.5

Polyethylene/aluminum/polyethylene (PE-AL-PE) pressure pipe

ASTM F 1282; CSA B137.9

High-density polyethylene (HDPE)

ASTM D 2737; ASTM D 3035; ASTM F 714; AWWA C901; CSA B137.1; CSA C448; NSF 358-1

Polypropylene (PP-R)

ASTM F 2389; CSA B137.11

Polyvinyl chloride (PVC)

ASTM D 1785; ASTM D 2241

Raised temperature polyethylene (PE-RT)

ASTM F 2623

1210.5 Fittings.

Ground-source heat pump pipe fittings shall conform to the standards listed in Table 1210.5 and, if installed underground, shall be suitable for burial.

Table 1210.5 Ground-Source Loop Pipe Fittings

Material

Standard (see Chapter 15)

Chlorinated polyvinyl chloride (CPVC)

ASTM D 2846; ASTM F 437; ASTM F 438; ASTM F 439; CSA B137.6

Cross-linked polyethylene (PEX)

ASTM F 877; ASTM F 1807; ASTM F 1960; ASTM F 2080; ASTM F 2159; ASTM F 2434; CSA B137.5

Polyethylene/aluminum/polyethylene (PE-AL-PE)

ASTM F 1282; ASTM F 2434; CSA B137.9

High Density Polyethylene (HDPE)

ASTM D 2683; ASTM D 3261; ASTM F 1055; CSA B137.1; CSA C448; NSF 358-1

Polypropylene (PP-R)

ASTM F 2389; CSA B137.11

Polyvinyl chloride (PVC)

ASTM D 2464; ASTM D 2466; ASTM D 2467; CSA B137.2; CSA B137.3

Raised temperature polyethylene (PE-RT)

ASTM D 3261; ASTM F 1807; ASTM F 2159; CSA B137.1

1210.6 Joints.

Joints and connections, other than those covered by Section 1210 and conforming to the ASTM standards listed therein, 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 in accordance with manufacturer's instructions for buried applications.

1210.6.1 Joints between different piping materials.

Joints between different piping materials shall be made with transition fittings compatible with both materials and the fluid contained within the system. Transition fittings must be used in accordance with manufacturer's instructions.

1210.6.1.1 Plastic-to-metal connections.

Soldering on the metal portion of the system shall be performed not less than 18 inches (457.2 mm) from a plastic-to-metal adapter in the same water line.

1210.6.2 Preparation of pipe ends.

Pipe shall be cut square, be reamed, and be free of burrs and obstructions. CPVC, PE, and PVC pipe shall be chamfered. Pipe ends shall have full-bore openings and shall not be undercut.

1210.6.3 Joint preparation and installation.

Where required by Sections 1210.6.4 through 1210.6.6, 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 a procedure in accordance with the manufacturer's instructions. Joints shall be welded in accordance with the manufacturer's instructions.

1210.6.4 CPVC plastic pipe.

Joints between CPVC plastic pipe or fittings shall be solvent-cemented or threaded joints complying with Section 1203.3.

1210.6.5 Cross-linked polyethylene (PEX) plastic tubing.

Joints between cross-linked polyethylene plastic tubing and fittings shall comply with Section 1210.6.5.1. 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.

1210.6.6 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 D 2657. 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 D 2683 or ASTM D 3261.

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 F 1055.

1210.6.6.3 Stab-type insert fittings.

Joint surfaces shall be clean and free from moisture. Pipe ends shall be chamfered and inserted into the fittings to full depth. Fittings shall be manufactured in accordance with ASTM F 1924.

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 F 2389.

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.

1210.6.9 PVC plastic pipe.

Joints between PVC plastic pipe and fittings shall be solvent-cemented or threaded joints comply with Section 1203.3.

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.

Exception: Shutoff valves shall not be required where heat exchangers are integral with a boiler; or are a component of a manufacturer's boiler and heat exchanger packaged unit and are capable of being isolated from the hydronic system by the supply and return valves required by Section 1005.1.

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.

1210.7.7 Reduced pressure.

A pressure relief valve shall be installed on the low-pressure side of a hydronic piping system that has been reduced in pressure. The relief valve shall be set at the maximum pressure of the system design. The valve shall be installed in accordance with Section 1006.

1210.8 Installation.

Piping, valves, fittings, and connections shall be installed in accordance with the conditions of approval.

1210.8.1 Protection of potable water.

Where ground-source heat pump ground-loop systems have a connection to a potable water supply, the potable water system shall be protected from backflow in accordance with the New York City Plumbing Code.

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 New York City 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 (121.1°C) shall have a minimum clearance of 1 inch (25.4 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.

1210.8.7 Pipe support.

Pipe shall be supported in accordance with Section 305.

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 (689.5 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. Embedded piping shall comply with Section 1209.