Bench testing radiator vent valves?

Jells

I have a box of MoM and Hoffmans of uncertain reliability. I'm having problems with tenant radiators that 'might' be defective venting, even though I've swapped out vents. I was thinking a test setup to check the functioning of a vent would be very useful. Is there an established design for this? I was thinking perhaps something as simple as a old aluminum pot with a tight fitting lid and a 1/8" pipe thread tapped in it's side would do. Alternatively, going higher tech a 1' x 3" pipe nipple with a cap at one end and a downsizing adapter at the other with a 15lb pressure relief valve and a 1/8" port to screw in a vent. Either one partially filled with water could just be placed over the kitchen burner to get it hot enough to produce steam and see if the valve functions properly.

neilc

before I messed with a pressure cooker bomb in my kitchen I would look for a way to pipe this off your boiler,
just another tee, valve, and plug, some nipples, etc,
from the pigtail Ptrol , or safety valve, or ??

Big Ed_4

Give them a try on a radiator you have access to , like the staircase or hallway radiator ..

Jells

Big Ed_4 said:

Give them a try on a radiator you have access to , like the staircase or hallway radiator ..

Lol, I pulled out the hallway radiator years ago! Heating a stairwell didn't make any sense at all to me.  But I'm currently renovating the first floor apartment. I did swap one that seemed to be working from one of my rads to the third floor but that's a very slow process to check out a whole bunch of them over 90 minute heat cycles.  

I think I'm going to try the pot lid method. Tap a 1/8 hole in a disc of aluminum that fits over a small pot without pouring sprouts and just put maybe a pound of weight on it. That should get some ounces of pressure but not much more. I went to the Home Depot to get some parts but those idiots were completely out of 1/8" nipples. Not only that, I bought a new MoM for them only to discover when I got it back that the plate was spinning in the crimping and it was obviously going to leak. Pathetic. 

ethicalpaul

I strongly doubt it was a real MoM if you got it from HD

Lard

My test rig is an old garbage-picked espresso machine with a pressure gage and bleed-off valve to control pressure. A piece of high-temp automotive coolant hose slips over the 1/8npt fitting and the (former) milk steaming wand. It is very effective

Jells

Lard said:

My test rig is an old garbage-picked espresso machine with a pressure gage and bleed-off valve to control pressure. A piece of high-temp automotive coolant hose slips over the 1/8npt fitting and the (former) milk steaming wand. It is very effective

Interesting. Did you add the pressure gauge and valve or was it part of the setup? I had a cheapo espresso once and there was just a valve to divert steam to the frother.

Gordo

@Lard: Hi! Your Espresso/vent testing set-up sounds like just the ticket!
Is it portable?
Could you post a picture?

Jells

ethicalpaul said:

I strongly doubt it was a real MoM if you got it from HD

Nope, genuine MoM in the orange box. I deliberately rummaged for it avoiding the no names.

I'm curious, does anyone know what the tongue on a Hoffman type does? Seems like an odd feature...

SteamingatMohawk

To the guys doing a DIY test rig using steam, don't forget that when water flashes to steam, it expands in volume by a factor of 1700! and that's the truth. Just ask Dan.

Don't get complacent about the stored energy in a closed vessel.

Jells

SteamingatMohawk said:

To the guys doing a DIY test rig using steam, don't forget that when water flashes to steam, it expands in volume by a factor of 1700! and that's the truth. Just ask Dan. Don't get complacent about the stored energy in a closed vessel.

Hence my proposal to simply use a weighted pot lid rather than an actually sealed rig.

SteamingatMohawk

It's not a problem until it is, then it's too late. Be safe, not sorry.

SteamingatMohawk

On a side note, I have a multi-family and didn't bother with the hallway radiator, either. Over a period of time I noticed paint peeling off the baseboards and couldn't understand why. This fall I repaired and painted the hallway. When I consulted my paint expert (26 years experience) he mentioned that it's possible for interior paints to peel if there are large variations in temperature. I said, "duh", that's exactly what I have. The radiator needed painting and I found a reasonably close company that sandblasted it and painted it for me. Also, with not-so-good weatherstripping, I found out how drafty it was in the hallway, making the problem worse.

Interior walls adjacent to an unheated hallway don't usually have insulation, potentially affecting the temperature in the rooms on the other side of the wall.

Food for thought.

My house is in the Albany, NY area.

Jells

My first building was composed of cold water flats so it never had always heating. I removed it from the next properties I bought. The halls are never more than 5 to 10 degrees cooler than the apartments. The heat loss from the apartments is the heat gain for the hallways! So in terms of temperature changes, the range from 70° to 90° in summer is far more than the 70 to 60 perhaps in winter.  The only real finish problem I have is in the one that never had heat, the plaster skim coat is delaminating from the brown coat in spots. But it's 120 years old or so, so these things you expect...

Lard

The BLEVE risk is exactly why I used a pre-made device (espresso machine) without much worry.  It already has built-in safeties that are quite strict, as it is a consumer-grade product, and it has a dump valve added to set pressure on top of that...  the main risk is burning, gloves handle that just fine.
The tapped lid for a pot works just as well and is cheaper unless you find an espresso machine in the trash (and have gages/valves lying around). I used what I had and like that this is portable and I don’t get in the way of dinner when testing vents!

It is currently in a different configuration since I used it to pop some particularly tenacious wallpaper but have a batch of vents coming that will need testing, so it will come back soon.

Gordo

@Lard: Thank you for your comments.
Please, when you can, post a picture of your espresso vent tester.