Expansion Relief Valve...

[Titanium Trades]

Gents,

Posted ref this before, Customer had a dishcharge into Tundish on unvented system, 1st: Re-charge expansion vessel (was 1.5bar now 3bar) = No Joy... 2nd: Replace Temp/Pressure relief valve = No joy!... Next I intend on replacing the Expansion relief valve, any other suggestions before I do this? I am G3 but not much experience on this to be honest... system is a Range Tribune HE, any help much appreciated.

 

[SimonJohns]

Is the cold balanced?
Is the ev good?

 

[chris watkins]

How big is the system / cylinder?
Did you not check the outlets of the two safety valves to see which one was discharging water ?
I would cut in a low cost pressure gauge so you can see what is happening pressure wise, maybe one on the inlet & one on the outlet of the pressure reducing valves (there are sometimes ports on the pressure reducing valves for this.)

 

[lbp plg & htg]

Start with incoming pressure - vessel should be set accordingly
Which valve is discharging?
What pressure have you measured from T & P Valve?

 

[Titanium Trades]

Cold is balanced and EV is fine, the T & P valve and ERV both dishcharge into same dish so couldnt identify which of the 2 was discharging. I havent measured the pressure from T & P valve...how can i? No gauge. Vessel is set at 3 bar as per reducing valve. There is a spare port on the PRV for gauge but if the PRV was bust and mains was over 6 Bar then this is cause of discharge? Many Thanks

 

[dancinplumba]

test press at hot outlet

 

[lbp plg & htg]

Undo the nut downside of the two valves - whichever is wet is the discharging on. You will need to invest in a pressure gauge though to work on these systems otherwise you'll be guessing as opposed to identifying.