How good is U.S.A.V radiator air valve? Is it ok to adjust heat by knob?

ShannonLee

My plumber came by last week to replace all my radiator valves by a brand called U.S.A.V.  The model number is A850. Has anyone ever heard of this brand? I couldn’t find anything online.
 So far there is no issue and the (old) steam heat system is finally quiet and balanced which I am happy with. 

But there is no way to adjust how much the heat coming out of this U.S.A.V air valve. My plumber said I can adjust the heat by twist the round knob . Is it a good idea? I do have extra vari valves and Hoffman 1A that I am thinking to use. But I am afraid to do so will jeopardize the balance and harmony of the system. I was also told the knob of radiator is better to open all the way up for whatever reason I am not quite sure. Will reduce the heat out of air valve be helpful to save money on the utility bills? The radiator in the picture is located in a room on the second floor which is not frequently utilized. Any suggestions? Thank you!  

Ironman

To avoid confusion: those are air vents, not radiator valves. The radiator valve is on the pipe coming into the bottom of the radiator. It must remain fully open or fully closed on a one pipe steam system.

You can control how fast a particular rad heats up by how fast the air vent releases air.

It appears that changing orifices on those vents changes the venting rate.

I can't say anything else about them except they're obviously made in China.

Big Ed_4

Look like an hardware store knockoff of a Gorton valve .. The Vari I would rarely use . They are designed for Appartment buildings .. I would use all 1A , And set valve to the size of the radiator . Start on the low end of settings

ShannonLee

Big Ed_4 said:

Look like an hardware store knockoff of a Gorton valve .. The Vari I would rarely use . They are designed for Appartment buildings .. I would use all 1A , And set valve to the size of the radiator . Start on the low end of settings

Can I adjust the heat by the round knob or not?

ShannonLee

Ironman said:

To avoid confusion: those are air vents, not radiator valves. The radiator valve is on the pipe coming into the bottom of the radiator. It must remain fully open or fully closed on a one pipe steam system.

You can control how fast a particular rad heats up by how fast the air vent releases air.

It appears that changing orifices on those vents changes the venting rate.

I can't say anything else about them except they're obviously made in China.

Well, that my confusion. Since my plumber said the U.S.A.V. air vents are designed to either fully open or fully closed. He asked me to to use knob to adjust how much heat to release. Do you think it would be ok? I was told the knob of radiator should be opened fully.. yes or no?

Lard

Those are china knockoffs of Maid ‘O Mist vents.  We like to call them “MoM’s” around these parts...

I see that the package has multiple orifices included. To control heat output to a point, change those knurled parts around.  To keep it simple, smaller hole=less heat, bigger hole=more heat.  #4 looks like your smallest, a 6 or D is installed, and D is your biggest.

Do not attempt to control heat output with the large valve by the floor. It must remain fully open to allow condensate (steam that has given up its heat) to drain out of the radiator. On the condensate subject, if the vent spits water, try a smaller orifice/hole.  The radiator runout/feed pipe can only handle so much condensate, too much vent (big hole) can overwhelm this capacity and allow water to build up and spit/gurgle/hammer.

AMservices

Yes the supply valve should be left fully open.
The interchangeable pieces that came with the air vent change how fast the radiator heats.
If the room gets to hot, change the orifice to a smaller one.
If its to cold, make the orifice bigger.

ShannonLee

Lard said:

Those are china knockoffs of Maid ‘O Mist vents.  We like to call them “MoM’s” around these parts...

I see that the package has multiple orifices included. To control heat output to a point, change those knurled parts around.  To keep it simple, smaller hole=less heat, bigger hole=more heat.  #4 looks like your smallest, a 6 or D is installed, and D is your biggest.

Do not attempt to control heat output with the large valve by the floor. It must remain fully open to allow condensate (steam that has given up its heat) to drain out of the radiator. On the condensate subject, if the vent spits water, try a smaller orifice/hole.  The radiator runout/feed pipe can only handle so much condensate, too much vent (big hole) can overwhelm this capacity and allow water to build up and spit/gurgle/hammer.

Thank yo sir for explaining it to me. If I had known, I would ask my plumber to use something Made in U.S.A , not "MoM's". The plumber installed #4 orifice on the first floor and #6 orifice on the second floor. He took all the package with him and didn't leave me any orifice once he finished installation so I guess I am screwed!? Maybe he didn't want me to find out these are actually knockoffs? Luckily I took pictures for my own record. I still thanks his service at least the steam system is quiet and in harmony.

ShannonLee

AMservices said:

Yes the supply valve should be left fully open.
The interchangeable pieces that came with the air vent change how fast the radiator heats.
If the room gets to hot, change the orifice to a smaller one.
If its to cold, make the orifice bigger.

Thanks. That is what I was told. I will leave the supply valve fully open. Question: When you put that interchangeable piece( orifice) on top of the air vent, did you screw it tight and leave it open? Or somewhere in between? Does it really matter?

Lard

ShannonLee said:

Lard said:

Those are china knockoffs of Maid ‘O Mist vents.  We like to call them “MoM’s” around these parts...

I see that the package has multiple orifices included. To control heat output to a point, change those knurled parts around.  To keep it simple, smaller hole=less heat, bigger hole=more heat.  #4 looks like your smallest, a 6 or D is installed, and D is your biggest.

Do not attempt to control heat output with the large valve by the floor. It must remain fully open to allow condensate (steam that has given up its heat) to drain out of the radiator. On the condensate subject, if the vent spits water, try a smaller orifice/hole.  The radiator runout/feed pipe can only handle so much condensate, too much vent (big hole) can overwhelm this capacity and allow water to build up and spit/gurgle/hammer.

If I had known, I would ask my plumber to use something Made in U.S.A , not "MoM's". The plumber installed #4 orifice on the first floor and #6 orifice on the second floor. He took all the package with him and didn't leave me any orifice once he finished installation so I guess I am screwed!? Maybe he didn't want me to find out these are actually knock off? Luckily I took pictures for my own record.

Time will tell how long these last. The alcohol capsule “”USAV” vents are garbage (different style than yours).

For the record, Maid ‘O Mist vents are made in the U.S.A. and are quite affordable and effective. These “USAV” vents are the same design/bimetal but made in China. Unlike the other style USAV, I do not have any experience as to longevity but.... if it looks like a duck...

Since he took the orifices, you have one easy option to increase venting: drill the hole larger. If you need less venting, you will need to acquire a new vent or orifice. The MoM equivalent to this USAV is 0220-5L. It comes with a full complement of orifices.

AMservices

Screw it down, finger tight. If its loose it kinda throws off the rating of the orifice.
I've seen those packages at Lowe's.

ShannonLee

Lard said:

ShannonLee said:

Lard said:

Those are china knockoffs of Maid ‘O Mist vents.  We like to call them “MoM’s” around these parts...

I see that the package has multiple orifices included. To control heat output to a point, change those knurled parts around.  To keep it simple, smaller hole=less heat, bigger hole=more heat.  #4 looks like your smallest, a 6 or D is installed, and D is your biggest.

Do not attempt to control heat output with the large valve by the floor. It must remain fully open to allow condensate (steam that has given up its heat) to drain out of the radiator. On the condensate subject, if the vent spits water, try a smaller orifice/hole.  The radiator runout/feed pipe can only handle so much condensate, too much vent (big hole) can overwhelm this capacity and allow water to build up and spit/gurgle/hammer.

If I had known, I would ask my plumber to use something Made in U.S.A , not "MoM's". The plumber installed #4 orifice on the first floor and #6 orifice on the second floor. He took all the package with him and didn't leave me any orifice once he finished installation so I guess I am screwed!? Maybe he didn't want me to find out these are actually knock off? Luckily I took pictures for my own record.

Time will tell how long these last. The alcohol capsule “”USAV” vents are garbage (different style than yours).

For the record, Maid ‘O Mist vents are made in the U.S.A. and are quite affordable and effective. These “USAV” vents are the same design/bimetal but made in China. Unlike the other style USAV, I do not have any experience as to longevity but.... if it looks like a duck...

You are the man! I just place order for five MAID O'MIST 0220-5L as backup. Sorry armature question : what the hell dos USAV mean? United States Air Vent?

ShannonLee

AMservices said:

Screw it down, finger tight. If its loose it kinda throws off the rating of the orifice.
I've seen those packages at Lowe's.

Thank you. You are awesome

Lard

ShannonLee said:

Lard said:

ShannonLee said:

Lard said:

Those are china knockoffs of Maid ‘O Mist vents.  We like to call them “MoM’s” around these parts...

I see that the package has multiple orifices included. To control heat output to a point, change those knurled parts around.  To keep it simple, smaller hole=less heat, bigger hole=more heat.  #4 looks like your smallest, a 6 or D is installed, and D is your biggest.

Do not attempt to control heat output with the large valve by the floor. It must remain fully open to allow condensate (steam that has given up its heat) to drain out of the radiator. On the condensate subject, if the vent spits water, try a smaller orifice/hole.  The radiator runout/feed pipe can only handle so much condensate, too much vent (big hole) can overwhelm this capacity and allow water to build up and spit/gurgle/hammer.

If I had known, I would ask my plumber to use something Made in U.S.A , not "MoM's". The plumber installed #4 orifice on the first floor and #6 orifice on the second floor. He took all the package with him and didn't leave me any orifice once he finished installation so I guess I am screwed!? Maybe he didn't want me to find out these are actually knock off? Luckily I took pictures for my own record.

Time will tell how long these last. The alcohol capsule “”USAV” vents are garbage (different style than yours).

For the record, Maid ‘O Mist vents are made in the U.S.A. and are quite affordable and effective. These “USAV” vents are the same design/bimetal but made in China. Unlike the other style USAV, I do not have any experience as to longevity but.... if it looks like a duck...

You are the man! I just place order for five MAID O'MIST 0220-5L as backup. Sorry armature question : what the hell dos USAV mean? United States Air Vent?

You may even get lucky and the MoM orifices will thread into the USAV’s (true knockoff design).

Yes, I believe the U.S.A.V. name is what you say... and it bothers me when things named as such are not even made here.

ShannonLee

Lard said:

ShannonLee said:

Lard said:

ShannonLee said:

Lard said:

Those are china knockoffs of Maid ‘O Mist vents.  We like to call them “MoM’s” around these parts...

I see that the package has multiple orifices included. To control heat output to a point, change those knurled parts around.  To keep it simple, smaller hole=less heat, bigger hole=more heat.  #4 looks like your smallest, a 6 or D is installed, and D is your biggest.

Do not attempt to control heat output with the large valve by the floor. It must remain fully open to allow condensate (steam that has given up its heat) to drain out of the radiator. On the condensate subject, if the vent spits water, try a smaller orifice/hole.  The radiator runout/feed pipe can only handle so much condensate, too much vent (big hole) can overwhelm this capacity and allow water to build up and spit/gurgle/hammer.

If I had known, I would ask my plumber to use something Made in U.S.A , not "MoM's". The plumber installed #4 orifice on the first floor and #6 orifice on the second floor. He took all the package with him and didn't leave me any orifice once he finished installation so I guess I am screwed!? Maybe he didn't want me to find out these are actually knock off? Luckily I took pictures for my own record.

Time will tell how long these last. The alcohol capsule “”USAV” vents are garbage (different style than yours).

For the record, Maid ‘O Mist vents are made in the U.S.A. and are quite affordable and effective. These “USAV” vents are the same design/bimetal but made in China. Unlike the other style USAV, I do not have any experience as to longevity but.... if it looks like a duck...

You are the man! I just place order for five MAID O'MIST 0220-5L as backup. Sorry armature question : what the hell dos USAV mean? United States Air Vent?

You may even get lucky and the MoM orifices will thread into the USAV’s (true knockoff design).

Yes, I believe the U.S.A.V. name is what you say... and it bothers me when things named as such are not even made here.

It bothers me too! Hopefully there are will be more Made in U.S.A. product

robertfromnj

Back to basics here: An air vent on a radiator allows air to escape from the system when the boiler first produces steam. When the air is vented from the system and steam gets to the valve, the valve should close, forming a closed system.

A air vent with a big orifice will allow that radiator heat first in the house. After that, performance should be the same.

An air vent has two failure modes: stuck shut or stuck open. A vent stuck shut will not release air; steam will not get to that radiator or take a long time. If the vent does not hiss gently when the boiler is warming, that's the problem.

A vent stuck open will hiss gently while air escapes, then hiss as steam escapes. This is potentially a problem for the boiler, because it will need to be refilled frequently with water. Proper operation includes a gentle hiss, followed by the vent closing. Mine close with a thunk.

The first fix for both conditions is the same. Remove the vent and soak in vinegar. I use a mild solution of muriatic acid. Rinse, then reinstall. It may take two treatments. My personal suggestion is to blame a clogged vent before blaming manufacture.

The second fix is replacing the vent. For the radiator to which you want heat first, get a vent with a big orifice or an adjustable one with the adjustment full open.

Just remember this about radiators. After they heat, they are not individually controllable. The air vent should shut completely. The supply valve at the bottom should be open fully. In the alternative, you could shut it off completely when it's cool, but that will mean no heat at all.