Belmont valve? Leaky radiator question

[A Coram]

I have a couple of these old radiator valves which are leaking. From what I have read, I believe they are Belmont valves, in which case they can be serviced in situ and are well worth servicing rather than replacing.

Two questions:

1. Could anyone confirm from the photos whether they are in fact Belmont valves?

2. If so, where can I source the correct o rings? I have read about two types, red and green, but how do I know what I need?

Many thanks for any suggestions!

 

[A Coram]

Here's a view with the cap on... If there was ever any branding on the top it is now illegible.

 

[A Coram]

Double post

 

[JohnD]

looks like it. have none of them got caps?

I went through this a few years back and may have some info lying around. I had a PDF of the instructions somewhere. I did a few but some were seized solid. If you ever fit TRVs, keep the old Belmont as a spare, clean it up and re-ring it to replace one of your others. Summer is the best time to tinker with CH.

If you manage to get one apart, use the same colouras before. IIRC you can also unwind the spindle and put a few turns of PTFE tape on it before reassembly.

The O rings are ludicrously expensive. The makers sent me a couple FOC out of charity.

Have a look at the old posts lower down this page.

edit

here it is. I think you'd use plumbers silicone white grease now.

 

[Gasguru]

They look like Belmonts to me.
I've yet to find out the differences between Peglers O rings for these valves apart from colour and stoopid price.
I use BS012 EPDM O rings, these are 9.25mm inside diameter x 1.78mm cross section.

You'll need 2 on each valve stem. In theory you can change the seals without draining the system or even dropping the pressure...but I'd at least drop the pressure or bung the F&E cistern etc.
Unscrew the thin top gland nut. Turn the spindle clockwise and it will detach itself from the lower valve plug. The lower valve plug should rise to seal the water.
Cleanup up the 2 ring gland grooves, apply silicon grease and fit the new seals. Refit.

 

[A Coram]

Thank you both for the replies. Very helpful indeed.

I have tried the ptfe wrapping idea to repack the spindle, but no luck.

I guess the next step is to bite the bullet and whip the spindle out, and hope these fancy valves do their job. Perhaps bunging the header tank would be worthwhile...

Gasguru, does this link look like the right size? (Described as 10x2mm, but they have correct BS number) www.amazon.co.uk/Rubber-Ring-BS012-Size-10x2mm/dp/B0051ODQ10

Alex

 

[Gasguru]

No, forget that lot.
Buy genuine O rings made from EPDM from a proper seal supplier. Plenty on eBay.

 

[Gasguru]

Use silicon grease.
I guess when these valves were introduced silicon grease wasn't the norm hence Castrol BNS.
I remember using BNS for front bearings in motorsport...I think it's long since obsolete.

 

[A Coram]

Thanks for the help!

A