Not quite the PRV?

[Ally703]

After trying to deal with an airlock in my open vented Oil fired CH system I rather stupidly undid a nut which I now believe was the end of the discharge pipe . I believe normally the PRV is at the other end of this pipe, within the boiler (Grant Euroflame), but I was working from the outside.

This nut had a hole in it, and it compressed a spring, after screwing this nut back I got curious as nothing flowed out so I took it right off, with the spring (those who see where this is going are right). I then was curious why nothing at all was coming out of the pipe so poked in and felt something flat in the pipe, this then popped out and quickly the water in the system drained on me. My only problem now is that when I re-seat this flat seal and screw the spring and nut back on it will not seal and so the system is just leaking out of the pipe when I refill.

I am guessing dirt is on the valve seat, or there was something else there that got lost when it popped. The problem is how do I replace it as I have no idea what I am looking for because I don't know what it is called. It doesn't look like any PRVs I have seen for sale for the boiler model and it looks more like a fixed pressure pop-off valve.

Could anyone give me any ideas?

 

[Agile]

This sounds like an old style of spring pressure release valve as were often used as an extra safety device on solid fuel boilers.

( There was one on my grandmother's coke boiler when I was a kid. I stopped by a few years ago when passing and knocked and there were the same people there who had bought the house after my grandfather died. House little changed apart from a Vaillant boiler to replace the coke stove. )

I would have expected it to have been designed to open at about 4 Bar and that the boiler would have had another built in PRV of a more modern design. But...

It was also exceedingly dangerous for you to poke about with something that you dont understand. You are lucky you did not lose an eye or get seriously scalded!

Safety is paramount on here! Rather than risk an explosion, get a CORGI or OFTEC to do it for you.

Tony

 

[namsag]

1/2 inch or 3/4 inch safety valve. fitted on most boilers 30 years ago,
No longer required on gas boilers just gets blanked off with a plug.
Oil is prob the same but see if anyone says different