Heating Valve Identification?

[CIM1]

Hi, I have an 1980's vintage Y-plan indirect system with a leaking valve close to the hot water tank on the return pipe to the boiler. However I am not sure exactly what its purpose is or what to replace it with?

Is it a manual or automatic air bleed valve or is it just a valve for restricting flow?

Here's a pic:

Thanks.

 

[PRS1]

ITs a gate valve with the hand wheel removed!

 

[ChrisR]

It'll be a balancing valve to restrict the flow through the HW cylinder, to avoid starving the CH system.
I wouldn't replace it unless it's leaking enough to be wet.

It's a Conex (make) which is good.
See comments on gate valves here:
//www.diynot.com/forums/viewtopic.php?t=263986

 

[expertgasman]

It's a Conex (make) which is good.

But not in the same league as Pegler

 

[CIM1]

It'll be a balancing valve to restrict the flow through the HW cylinder, to avoid starving the CH system.
I wouldn't replace it unless it's leaking enough to be wet.

It's a Conex (make) which is good.
See comments on gate valves here:
//www.diynot.com/forums/viewtopic.php?t=263986[/QUOTE]
Thanks for replies - it drips when the water heating kicks in so needs either repairing or more likely replacing - as far as I can see it is leaking from both gland and body but is manageable until I drain down and replace.

As it is working as a restrictor, when I replace, how best to rebalance safely/effectively?

 

[bengasman]

It is probably a restrictor to balance the flow through the cylinder, but it could be a "bypass".