How can you tell if your using the right pressure relief valve on a boiler?

bender1227

I have a Weil Mclain CGT boiler. Here is a picture of the side plate. https://imgur.com/a/9BEeHxx

The max pressure is 30 psi and the input btu/hr is 133,000 for the boiler.

I bought a Zurn pressure release valve P1000AXL-30C. The tag on the relief valve says 30 psi and 510,000 btu/hr. I'm assuming that this pressure relief valve won't have any issues working with my boiler.

Let me know if you see any issues.

Thanks!

EBEBRATT-Ed

you fine. if you look at the nameplate it says relief valve capacity 108 mbh. thats 108,000 btu. the relief valve can always be larger in btu rating but the 30 psi is the same

bender1227

@EBEBRATT-Ed Okay thank you. That's what I thought, but when I looked up the specs on the relief valve on Zorns website they didn't say anything about boilers. I was assuming if the pressure and the btu's are set correctly on the valve your covered.

bender1227

So I called up Zurn and asked the if this valve can be used on boilers; they said no but the guy on the phone didn't know exactly why. I'm returning it and bought another one that's approved for boilers. There might be a component in it that can't handle hot water.

EdTheHeaterMan

That particular valve is part of a group of products that are designed for water heater storage tanks. The more common valves for water heaters have higher pressure ratings of 125 PSI or 150 PSI, but they also have lower pressure ratings of 75 PSI and even this one as 30 PSI. The other feature if this series of valves is that most of them have a temperature setting of 210° which is a requirement for water heater storage tanks.

Some water heaters do not require the temperature probe like tankless water heaters. This may be designed for low pressure open system low pressure water heating equipment. This does not mean that it would not work for your boiler, but it has features that you do not need. Food grade rating is not necessary for a boiler but it does not make it unsafe for boiler usage. You just don't need to spend the extra $$$ for features that are not necessary. A boiler rated 30PSI relief valve will be less costly in most cases.

Here is the spec sheet for the Zurn Valve
https://www.zurn.com/media-library/web_documents/pdfs/specsheets/tp-tp-p-c-pdf

EdTheHeaterMan

How can you tell if your using the right pressure relief valve on a boiler?

After looking at this discussion for several minutes a thought came to mind.
Q. How can you tell if your using the right pressure relief valve on a boiler?
A. When the boiler blows up you know it was the wrong one.

GGross

bender1227 said:

So I called up Zurn and asked the if this valve can be used on boilers; they said no but the guy on the phone didn't know exactly why. I'm returning it and bought another one that's approved for boilers. There might be a component in it that can't handle hot water.

Its a pretty standard relief valve, except it is lead free. It is not to be used on steam systems so it could be the Zurn rep told you not to use it on a boiler just to be safe in case you have a steam system. This would be fine for a hot water boiler system, as it is designed for a hot water storage tank. You do not need a lead free version though, so probably save money by getting the standard lead version

bender1227

Thank you all for the information!

bender1227

What is the consensus on using Shark Bites in boiler systems? I see that they have versions of their products rated for use in them, but do you see a lot of people using them?

dko

Zurn Wilkins relief valves are rebranded Cash Acme valves.

https://www.cashacme.com/us/en/temperature-pressure-relief-valves/f-30
This is the exact valve you have and while Zurn doesn't state outright it is for water boiler use, cash acme does.

Jamie Hall

bender1227 said:

What is the consensus on using Shark Bites in boiler systems? I see that they have versions of their products rated for use in them, but do you see a lot of people using them?

Not sure how that got into this thread, but... my opinion? As a temporary fix for something when you'll be back the next day with the correct fittings, OK if rated. But not permanent.