VIEGA Rotguss Double Nipple 1″ Male x Male Thread, Gunmetal (Brass Alloy), Art. 266608

It joins two parts that both end in a female thread, such as a valve and a fitting, so they meet on one axis with no pipe between them. This version has an R 1 male thread at each end and therefore needs a 1" female port on both sides; being 45 mm long, it keeps the two parts close together.

Both ends are R threads: tapered male threads to DIN EN 10226-1 that are made to go into parallel Rp female threads. The seal forms in the thread itself, without the flat gasket a G thread relies on. Viega allows hemp with sealing paste, PTFE thread tape or thread-sealing cord, and any sealant used must be non-hardening and carry the DVGW mark.

For the polygonal centre of Art. 266608, Viega lists a spanner size of 34 mm, and its manual names a pipe wrench or an open-ended spanner for these fittings. Before assembly, make sure both R 1 threads are undamaged: a part that leaks in the load and leak test because of a damaged thread has to be replaced.