Compression coupling REHAU 20 mm to G3/4 threaded connection (model 137985001)

Compression coupling REHAU 20 mm to G3/4 threaded connection is a mechanical adapter designed to join 20 mm plastic or multilayer pipe to a G3/4 external or internal threaded fitting. The coupling provides a compact, mechanical seal without the need for soldering or adhesive, enabling a secure transition from push-fit pipe systems to standard G3/4 threaded components in plumbing, heating and water supply applications.

Advantages

The coupling ensures reliable, leak-resistant connections and simplifies installation by eliminating the need for heat or chemical joining methods. Its compact design saves space in confined installations and is compatible with common 20 mm plastic and multilayer pipes. The threaded end accepts G3/4 fittings, allowing integration with valves, taps and appliances that use standard G3/4 threads. Materials and construction are intended for long-term mechanical performance in potable water and heating systems when installed according to instructions.

Suitable for

• Connecting 20 mm plastic or multilayer pipe to G3/4 threaded valves and fixtures
• Domestic and commercial hot and cold water distribution systems
• Heating circuit connections where a push-fit to thread transition is required
• Repair or modification of existing piping to add threaded components

Key specifications

• Pipe connection: 20 mm compression for plastic or multilayer pipe
• Threaded connection: G3/4 compatible external/internal thread
• Function: Mechanical compression coupling for secure, solder-free joints
• Application areas: Plumbing, heating, water supply systems
• Design: Compact form factor for space-limited installations

How to use

Prepare the pipe end by cutting squarely and removing any burrs. Slide the compression nut and insert the sleeve if required, push the pipe fully into the coupling until it seats against the internal stop, then tighten the compression nut to create the mechanical seal. Thread the G3/4 connection onto the corresponding fitting and tighten to the recommended torque for the mating component. Follow standard installation practices and local codes for water and heating systems.

Usage recommendations

Use with compatible 20 mm plastic or multilayer pipes and G3/4 threaded fittings only. Verify pipe material and wall thickness meet manufacturer guidelines. Do not use solvents or solder; ensure connections are tightened to appropriate torque and inspect for leaks after pressurization. For installations in heating systems, follow recommended temperature and pressure limits for plastic and multilayer piping.