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New York City · Through Local Law 2026/135 (enacted August 31, 2026)

N.Y.C. Admin. Code § MC 1203: Section MC 1203: Joints and Connections

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Where this section sits in the code
  1. New York City Administrative Code
  2. Title 28
  3. Chapter 8: New York City Mechanical Code

1203.1 Approval.

Joints and connections, other than those contained in Section 1203 and conforming to the ASTM standards listed in Section 1203, 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 rated for the temperatures and pressures of the systems in which the devices are installed and shall be compatible with the fluid and all materials provided.

1203.1.2 Joints between dissimilar metallic piping materials.

Joints between dissimilar metallic piping materials shall be provided to protect against galvanic corrosion. Such joints shall be made with dielectric fittings conforming to ANSI B16.39 or ASTM F 492, as applicable, shall be rated for the temperatures and pressures of the systems in which the devices are installed and shall be compatible with the fluid and all materials provided.

Exception: Dielectric fittings shall not be required for joints between dissimilar metal piping used within heat transfer appliances or equipment when such joints are provided by the appliance or equipment manufacturer, and such appliance or equipment is connected with isolation valves that are accessible.

1203.2 Preparation of pipe ends.

Pipe shall be cut square, reamed and chamfered, and shall be free of 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 1203.14, 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.

1203.3.1 Brazed joints.

All joints shall be brazed with a brazing procedure developed and qualified in accordance with the ASME Boiler and Pressure Vessel Code, Section IX (Welding and Brazing Qualifications) or in accordance with AWS B2.2 standard for Brazing Procedure and Performance Qualification.

1203.3.2 Mechanical joints.

Mechanical joints shall be installed in accordance with the manufacturer's instructions.

1203.3.3 Soldered joints.

Joint surfaces shall be cleaned. A flux conforming to ASTM B 813 shall be applied. The joint shall be soldered with a solder conforming to ASTM B 32.

1203.3.4 Solvent-cemented joints.

Joint surfaces shall be clean and free of moisture. A primer, compatible with both the piping material and the cement shall be applied to pipe-joint surfaces, in accordance with the manufacturer's requirements. Joints shall be made while the cement is wet. Solvent cement conforming to the following standards shall be applied to all joint surfaces:

1. ASTM D 2235 for ABS joints.

2. ASTM F 493 for CPVC joints.

3. ASTM D 2564 for PVC joints.

1203.3.5 Threaded joints.

Threads shall conform to ASME B 1.20.1. 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 compatible for application on the piping material and fluid.

1203.3.6 Welded joints.

All joints shall be welded with a welding procedure developed and qualified in accordance with the ASME Boiler and Pressure Vessel Code, Section IX (Welding and Brazing Qualifications) or in accordance with AWS B2.1 Specifications for Welding Procedure and Performance Qualification.

1203.3.7 Grooved and shouldered mechanical joints.

Grooved and shouldered mechanical joints shall conform to the requirements of ASTM F 1476 and shall be installed in accordance with the manufacturer's instructions.

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.

1203.3.8.2 Brazed joints.

Mechanically formed tee fittings shall be brazed in accordance with Section 1203.3.1.

1203.4 ABS plastic pipe.

Joints between ABS plastic pipe or fittings shall be solvent-cemented or threaded joints conforming to Section 1203.3.

1203.5 Brass pipe.

Joints between brass pipe or fittings shall be brazed, mechanical, threaded or welded joints conforming to Section 1203.3.

1203.6 Brass tubing.

Joints between brass tubing or fittings shall be brazed, mechanical or soldered joints conforming to Section 1203.3.

1203.7 Copper or copper-alloy pipe.

Joints between copper or copper-alloy pipe or fittings shall be brazed, mechanical, soldered, threaded or welded joints conforming to Section 1203.3.

1203.8 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 1203.8.1 or push-fit joints conforming to Section 1203.8.2.

1203.8.1 Flared joints.

Flared joints shall be made by a tool designed for that operation.

1203.8.2 Push-fit joints.

Push-fit joints shall be installed in accordance with the manufacturer's instructions.

1203.9 CPVC plastic pipe.

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

1203.10 Reserved.

1203.11 Cross-linked polyethylene (PEX) plastic tubing.

Joints between cross-linked polyethylene plastic tubing and fittings shall conform to Sections 1203.11.1 and 1203.11.2. Mechanical joints shall conform to Section 1203.3.

1203.11.1 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.

1203.11.2 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.

1203.12 PVC plastic pipe.

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

1203.13 Steel pipe.

Joints between steel pipe or fittings shall be mechanical, threaded or welded joints conforming to Section 1203.3.

1203.14 Steel tubing.

Joints between steel tubing or fittings shall be mechanical or welded joints conforming to Section 1203.3.

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 F 2389.

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 and 1203.16.2. 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 (457.2 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 (457.2 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 (457.2 mm) of a transition from such metal pipe to PEX-AL-PEX pipe.

Collected 2026-09-06T02:48:57Z. Source file · JSON

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