Purmo radiator accessory — RS extension coupling 1/2" L-20 (model 1141)

Purmo RS extension coupling 1/2" L-20 (model 1141) is a threaded radiator accessory designed to join or extend 1/2" heating pipe connections with a length of 20 mm. It is intended for use in central heating systems where a short, reliable threaded extension is needed to adapt radiator valves, modify pipe runs, or replace worn fittings. The coupling provides a compact solution for maintaining alignment and proper thread engagement between radiator components in both new installations and repairs.

Advantages

The extension coupling offers a compact, robust threaded connection compatible with standard 1/2" radiator fittings. Its L-20 length helps achieve the correct spacing for valve installation and ensures secure engagement of existing threads. The simple mechanical design reduces installation complexity and allows straightforward replacement without the need for extensive pipe modification.

Suitable for

• Extending 1/2" threaded radiator connections by 20 mm
• Adapting radiator valves to different pipe recess depths
• Replacing damaged or corroded short couplings in heating circuits
• Professional plumbing installations and DIY radiator maintenance

Key specifications

• Connection thread size: 1/2" (threaded coupling)
• Overall extension length: 20 mm (L-20)
• Type: RS extension coupling for radiators
• Application: central heating radiator connections

How to use

Ensure the heating system is isolated and cooled before disconnecting any components. Remove the existing fitting if necessary and inspect thread condition. Hand-start the coupling onto the male or female thread, then tighten with an appropriate wrench to achieve a secure, leak-free joint without over-torquing. Refit the valve or pipework and pressurize the system to check for leaks. If thread sealant or tape is required, use materials suitable for heating systems and compatible with metal threads.

Usage recommendations

Use the coupling where a short 20 mm extension is sufficient to align radiator valves or restore proper thread engagement. Verify thread compatibility and material condition before installation, and perform a pressure test after fitting. For critical installations or uncertain thread condition, consult a professional plumber.