Compression Coupling SiGMA-Li MP321 32 x 1" with Half-Union

Compression coupling SiGMA-Li MP321 32 x 1" with Half-Union is a plumbing fitting designed to join a 32 mm pipe to a 1" threaded component using a compression connection and a half-union (half-screw) interface. The fitting provides a mechanical seal without soldering or welding and is intended for use in water supply and heating installations where a removable threaded connection is required. Made by SiGMA-Li, the coupling facilitates a transition between metric pipe diameter and imperial threaded fittings while maintaining a compact footprint.

Advantages

The compression coupling offers a secure mechanical connection that can be installed with basic plumbing tools, reducing the need for hot works. Its half-union design allows easier assembly and disassembly of threaded components for maintenance or equipment replacement. The product is suitable for systems where a tight seal, mechanical reliability and straightforward installation are priorities.

Suitable for

• Connecting 32 mm plastic or metal pipes to 1" threaded valves, taps or appliances
• Use in domestic and commercial water supply systems
• Heating circuits where a removable threaded connection is required
• Retrofit and repair works where conversion between metric pipe and imperial thread is needed

Key specifications

• Connection type: compression coupling with half-union (half-screw)
• Pipe compatibility: 32 mm outer diameter
• Thread compatibility: 1" threaded component
• Application: potable water and heating systems
• Installation: mechanical compression joint, no soldering required

How to use

Prepare the pipe end by ensuring it is cut square and free of burrs or debris. Slide the compression nut and ferrule onto the pipe, insert the pipe into the coupling body until it seats fully, then hand-tighten the nut onto the half-union. Use suitable wrenches to tighten to a firm mechanical joint according to typical plumbing practice, taking care not to overtighten and damage the ferrule or thread. Once assembled, check the connection for leaks under working pressure and retighten if necessary.

Usage recommendations

For reliable long-term performance, use compatible pipe materials and ensure the pipe outer diameter matches 32 mm. Follow local plumbing codes for use in potable water systems and inspect joints after initial pressurization. If installing in heating systems, verify temperature and pressure ratings of adjacent components to ensure overall system compatibility.