Nice quality lockshields

[JohnD]

I have never paid much attention to rad valves in the past, but I have been giving my system a flush and need to replace the old TRVs, I also picked up a couple of Danfoss RLV-D on Fleabay and they look to be so much better than my old ones that I'm thinking about changing the lockshields as I work round. I do have to watch the pennies though.

However I can't see good ones going cheap at places like Screwfix. Maybe there isn't much demand? Any suggestions? I only need another 6.

 

[Rob]

Use these ones all the time. In HPS they call the make is known as 'Stella'.

http://www.tradeplumbing.co.uk/Giac...alve-skin-pack-quality-valves_p_829-4119.html

 

[dan2071]

Is the Insert Pre - wrapped in PTFE?

 

[Gasguru]

All the cheap valves do not incorporate a seperate seal around the spindle. They often leak especially on sealed presurised systems. Although the Stella is an exception ie tends not to leak I would suggest upgrading to the Aquarius instead http://www.giacominisales.co.uk/AQUARIUS_10-011GB.pdf

In large quantites they are under £4.00.

These have a graphite/PTFE packing around the spindle and a gland nut. They will never leak. The PTFE coating on the tail has now been replaced with an elastomer seal instead. The original PTFE coating would not allow the tail to be fitted to all radiators. I used to cut it off and use PTFE tape. Remember to tighten down the gland nut. Aquarius are the only quality 3/4 Eurocone valve on the market and are ideal for replacing all the cheap leaking valves (which tend to be Eurocone fitting).

For a 1/2 compresion fittings then use Peglar Terriers, Plumbcenters equivalent, Altecnic Eclipse. Never use Myson Matchmate..they are total rubbish. Never use any valves without the extra gland nut. Never use valves incorporating O rings to seal the spindles...they always leak in the end...when the rings go brittle.

Unfortunately many of the matching lockshields sold with TRVs (including Danfoss) use O rings as the spindle seal...ie ditch them.

Most diy sheds don't sell a single decent valve...they are all imported carp from India/China.

 

[JohnD]

that's useful info, thanks.

So, Gland nut = good, "O" rings = bad, you reckon?

Shame about the Danfoss, they look so smart

 

[Gasguru]

You also find the rubbish valves don't even have a manufacturers name on the cap, others to be avoided are Cosmos, Voque, Beta, anything packed with a rad pack deal, any valve given away free with a radiator, nearly all the valves from b&q/screfix etc.

Ignore the 10 Bar test pressure claim...at that presure the O ring is distorted to such an extent it will always seal. At normal boiler pressures and once the ring has degraded it won't.

BS2767 Part 10 is a starting point but some of the good valves don't necessarily comply with this standard since it's flawed.


Fit the Danfoss but just don't expect them to seal in 5 or 10 years time when you adjust the lockshield to take a rad of or re-balance.

Even top range Pegler Belmonts use O rings.....they always leak eventually and although O ring kits are available is far cheaper to replace the valve.

I spend half my life changing rad valves...