Heating Help

2.5 inch Kunkle reilf valve

I have installed 2 new kunkle 2.5 inch reilf valves and they both leak. its a 15lb  steam system. we have changed psi gauges we hold 11.5 to 12 psi steady. The owners keep up on treatment and blow downs. need help

Brand

That is not uncommon for Kunckle relief's. Have you tried manually lifting them to see if they will re-seat? Otherwise, either 2 new valves or try another manufacturer, such as consolidated. I feel your pain...

brand

Thanks Tom  What do you know about Conbraco brand?

Leaking from where?

Leaking from where? Where you screwed the valve in? Or is the valve discharging due to high pressure? Is this residential boiler?  Is this two boilers? TWO relief valves on the same boiler??  Could you attach picture(s)?

leaking

It is one Boiler for a laundry, 3 valves have been tried they all leak out the discharge, we have installed 3 different psi gauges it never goes above 12lbs.

Relief valve goes off?

NOT A PLUMBER.  Pressure relief valve goes off? I would suspect pressure gets too high.  Pressure gauge reads never more than 12 lbs?  Some pros would know for sure, but many of these devices are not high precision devices so 12 lbs on the gauge may be only 'about' 12 lbs  and may be high enough to trip the 15 lbs relief valve.
Is this a steam boiler that also heats the house and also makes hot water? Could you  attach pictures?

Iam a plumber

Old one started to leak ordered a new one 3 times they all leak. is steam psi different then water psi?

What is the boiler rated for pressure?

The relief may be too close to the pressure you are running. What is the model and make of boiler?

2.5 inch Kunkle valve

Boiler is rated for 15lb steam it is a keewanee it is over 20 years old. Boiler provides steam for dryers and has a coil for domestic hot water.

Valve sizes

Even though that valve is sized for 15 lbs is it sized to the proper btu ? I have even seen some boiler manufactures ship smaller  rated safeties with there boiler then what is really needed .Example 1.5 mbtu boiler valve from the manafacture only rated for 975 btu did the valve weep yeap was the boiler pressure to high no beacause the boiler operate on a vaporstat replaced the valve with the properly rate valve and the valve weeping stopped ,big differene you bet old valve from the manafature was about 100 buks or so proper valve was about 225 so you tell me who cutting corners ? By the way the inspector and the  original contractor did not pick up on it .I got the proper valve and that was the end of the weep safety .Safety valves are rated for pressure and btus hek your boiler rating plate against the valves btu rating.Peace and good luck clammy