Fitting brass 3/8" 20mm hex 20

A welding end cap nut is used to put pressure on the welding cap so it seals against the conical surface of it. Once there is not enough pressure from the back from the welding cap nut, the seal won’t work.

This type of welding end cap is slightly different then the standard types of caps.

To start, this welding end cap is a male thread instead of a female thread. This type of welding cap nut can be seen for instance at the water inlet flange of a old E61 espresso machine. From the main filling valve there goes a tube towards the water level flange and the fitting which goes into that female thread, is this one.

This thread has a male thread of 3/8” BSP-G. The inner hole is 14mm. this fitting is compatible with a 8mm tube and a matching welding fitting.

The compatible items can be found in the accessory list below.