Hoffman Quick Valve Model 4 Not Closing

dkirkwood

First, a big thanks to all who have responded to my questions over last months--I have trying to find where I am leaking steam, as the boiler is using about 1 gallon of make up water a week.

My system is a one pipe, wet return is completely exposed, not buried, not leaking. I have found several radiator service valves and vents that are leaking steam.

Today I checked the mains, which are only about 2 years old--Hoffman Quick Valve Model 4 --there are 2 of them--that was the valve that was there before I put in the new ones 2 years ago.

They are definitely not closing--or more accurately, a noticeable amount of steam is blowing out, well into the steam cycle, when all the house radiators are full of steam and hot--I am no pro, but I am assuming this is definitely not correct behavior.

Any thoughts on why they don't close? I am assuming dirt from the steam pipes is causing the problem--can these things be successfully cleaned and put back into service? If so, how do I clean them--just use vinegar soak as recommended for radiator vents?

Thanks for the help

Jamie Hall

Vinegar soak may work. They are built very like radiator vents.

However. May I ask what your maximum pressure is? No vent likes pressure much...

Steamhead

Also, most times we encounter these vents, they're too small. How long are your steam mains, and what pipe size?

dkirkwood

the pressure is between 1 and 1.5 psi

As to second question: it is 2" pipe for the 2 mains--both are 38 feet long--do you think there is a better choice than the Hoffman 4 for this pipe size/length and operating pressure?

Steamhead

Sure is. If you have the headroom, put a Gorton #2 on each one. These vents are 6-1/2" tall, including the part that threads into the pipe, so measure before you buy them. But they will make those H-4 vents look like toys.

dkirkwood

Thanks for advice--I have to get into a crawl space to measure so I will tomorrow--one question...if there is a joist directly above the valve--would it be permissible to add an elbow to the current riser nipple, the use a small nipple with another elbow to position the valve so it's height could be accommodated in space between joists?

Steamhead

That's what I'd do. Just make sure the horizontal portion pitches back toward the steam main, so it doesn't hold water.