Lockshield vs Radiator Valve

[anon]

From earlier posts on this topic it appears that a 'LockShield Valve'

or a 'Radiator Valve' can be used to balance DCH flow.

Apart from about 4 quid, the obvious difference to me is that the radiator connection on the LSV is external by means of spanner, and the RV is internal by allen key and the LSV appears to have a crush type copper washer to seal the valve instead of a spherical seating.

One benefit of the LSV is that it's possible to use 2 opposing spanners to prevent the threaded radiator insert from rotating when tightening the valve - whereas with a RV there's a risk of the insert moving and accidentally bending the 15mm copper pipe.

I've pretty much answered my own query but would appreciate any comments, particularly on the copper crush washer - i.e. are they one shot items that are replaced if the rad is removed?

If anyone is thinking of replacing please note that the centres appear to be the same as TRV at about 45mm from the end of the rad, instead of

35mm for a RV.

[Roger Mills]

I think you're getting a bit confused with terminology!

A manual radiator valve and a lockshield valve are excatly the same animal - the only difference being that a RV has a knob to enable the shaft to be rotated whereas a lockshield has a non-rotating cover - which is fitted after adjusting the valve with a small spanner. Many valves are supplied with both types of head/cover, so that you can use them for either application.

All valves come in two main parts - the tail which screws into the radiator, and the working part of the valve itself. Tails have either an internal hexagon, allowing them to be screwd in using an Allen key, or an external hex or square allowing them to be screwed in using an open-ended spanner.

The two parts fit together using either a conventional compression fitting with olive and nut (in which case the tail has a plain end) or using conical mating surfaces and a back-nut. The sort which use compression fittings can be fitted either way round - with the shaft either vertical or horizontal. Many TRVs are made this way.

[anon]

Yes, I'd go along with that Roger! A closer look at my new TRV's (same 'tail' as the LSV's at Screwfix) have olive compression joints - not a flat washer as I first thought.

I was refering to the tail which has a spherical / radius / torus seating (to fit the valve cone)

It's worth pointing out LSV's extend a further 10mm so anyone replacing a RV for a LSV needs to be able to move the pipe or elongate the hole in the floorboard.

I'm converting a single pipe system to twin pipe and replacing the radiators for convector type. The old RV's were perfectly servicable so I've used the best one for upstairs and will probably go for LSV's for downstairs as they look neat and may have the edge on RV's for tightening and watertightness.

Many thanks for your comments Roger

[anon]

PS - While as a valve they are exactly the same Screwfix designate those with the an externally fitted tail & compression fitting as "Lockshields" and those with an Allen Key tail & cone joint as "Radiator Valves" I think Wickes do the same.

[chris French]

In message , anon writes

Err, this depends on the valves used. some makes models will be the same, some different.

[Roger Mills]

I don't think that's true! For example,

has an external spanner fitting on the tail and compression joints - but is designated as an RV.

SF seem to have more or less given up on what they call "wheelhead" valves - and only have TRVs and lockshields - so there are precious few manual valves to compare with their lockshield counterparts.

[Roger Mills]

I said no such thing - it was written by 'anon'. Please be careful when trimming to make sure that you quote the right source!