lockshield vs control/flow valve

[u0362565]

Hi all,

On my radiators which don't have TRV's, on one valve is a plastic cap which can be turned which i assume to be the control/flow valve and the other valve has no cap, just a square head that could be turned with pliers. When balancing you alter the lockshield valve, how should the control/flow valve be set relative to the lock shield valve on the other end? Is the lock shield always on the flow or return end of the radiator?

Thanks

 

[walterwhite]

Doesn't matter which end the lockshield is. Fully open the other valve and balance the rad with the lockshield to achieve the desired temp drop across the rad

 

[plumben]

It doesn't matter which end the lock shield is on, fully open the other valve/s and balance the system then the other valve is used to adjust the temp, think of it like a trv fully open would be like 5 on a trv and nearly closed would be like frost setting

 

[stani]

Surely the lock shield needs to be on the outlet of the radiator

 

[walterwhite]

Surely the lock shield needs to be on the outlet of the radiator

Why? Explain your thoughts!

 

[stani]

So you can control the flow out of the radiator, thereby regulating the return temp differential

 

[walterwhite]

You can control the flow through the rad on the return or flow.....it makes no difference.

 

[plumben]

But your valves need to be bi directional

 

[lame plumber]

standard practice was to have the lockshield on the outlet, and the wheelhead on the inlet, trvs have replaced the wheel head but modern trvs are bi directional, so doesnt matter which end they are on, but most of us like to keep normal practice going, so we can id flow and return pipes for one reason, and keep life simple

 

[stani]

You can control the flow through the rad on the return or flow.....it makes no difference.

So, with your thinking, if the return valve is wide open, and you turn down the flow into the radiator how do you maintain a differential.

 

[lame plumber]

So, with your thinking, if the return valve is wide open, and you turn down the flow into the radiator how do you maintain a differential.

you need to get your flow/return lockshield / trv sorted out as your mixing things up here and making life harder than it is.

 

[stani]

Just cocking it up writing it.

Trv on flow, lock shield on return easy.

 

[u0362565]

Ok thanks guys, I assume there's actually no difference physically between the flow and lockshield valves but to achieve the correct temp drop across the rad I'd have thought you'd need to adjust both to achieve the right differential.