Vapor return

STEAM DOCTOR

Found one of these on a vapor system. There is a pipe running from the header into this device and another pipe running from the device to the return. I have to crack out my copy of lost art. I am assuming that this device allows steam into the return when there is a build up off boiler pressure. The idea would be to turn the B dimension into an A dimension. Any info (i.e. names, mechanical details) would be greatly appreciated. If I want,can I install a vaporstat and remove this device? With the lower boiler pressure, this device should not be needed.

Thanks,

Aaron

STEAM DOCTOR

Malfunction

Do these things go bad? Is there a possibility that it wont let steam into the return when it should or that it will let steam into the return when it shouldn't?

JStar

Vapor

It's a Direct Return Trap. It is not needed with modern controls (Vaporstat). If you do take it out, mail it to me? We usually leave them in place for the next guy to enjoy in 100 years.

STEAM DOCTOR

Drawbacks

Are there any drawback to leaving it in? If I take it out, I will be adding it to my collection. You are always welcome to come visit.

JStar

Vapor

Rats!



We leave them in all the time. No drawback. If it leaks or fails, then you can rip it out. If it hasn't leaked in 100 years, when will it?

STEAM DOCTOR

Passing steam

Is it possible that it will pass steam into return when it shouldn't? Also, any info on rad valves in my other post?

JStar

Vapor

Technically, the steam and return connections should never be open at the same time. Is there a valve on the steam line? You can shut it off to be safe.



http://www.heatinghelp.com/files/articles/1323/58.pdf

STEAM DOCTOR

No valve

There is no valve on the piping leading to or from the return trap.

Dave in QCA

No Reason to Remove

The great old return traps are usually removed because someone doesn't understand how they work and then they just rip them out. Never heard of one actually failing.



The operation is so simple. In normal low pressure operation, say 8 oz, you have enough B dimension that the condensate flows into the boiler by gravity. When the pressure rises, you have a problem. Even with a vaporstat, it is not a bad idea to have this device in place as a backup. I curse the knucklehead that removed the return trap from my Dunham system!



When the boiler pressure rises to the point that the condensate does not return to the boiler, it will flow into the return trap through the bottom port. One of the two pipes at the top leads to a vent device, which we cannot see in your photo. The other pipe is connected to the steam supply. A float operated trip valve inside the return trap has the steam port normally closed and the vent open. This allows the condensate to flow in. When the condensate gets to a high level in the return trap, the float rises and trips the valve to the other position closing the vent port and opening the steam port. Now, the pressure in the return trap is equal to the boiler and the condensate falls out of the return trap and into the boiler by gravity. As soon as the level in the return trap falls, the float trips the valve back to the original position and the cycle begins again. Very simple and it only has to do its work when the boiler pressure is high, usually very rarely. So, it probably had another 100 years of life in it.



Like I said, we can't see how the vent port is connected, but it probably is not connected directly to the return piping. These are usually only connected to return piping down near the floor and so I really don't see how this return trap could fail on put steam into your return piping. You really don't need to be worrying about that.

STEAM DOCTOR

Vent port

One pipe goes from the header into the return trap. The other pipe goes from the return trap directly into the dry return. There is a Hoffman 74 vent at the end of the dry return(looks a lot like the Hoffman#75).

Dave in QCA

Factory Information

I was wrong in my assumption that the vent connection was not venting through the return lines. Even with that being the case, I doubt there is a reason to worry about it.



Here are a couple of links to information that is in the HH library.



http://www.heatinghelp.com/files/articles/1381/317.pdf



http://www.heatinghelp.com/files/articles/1323/58.pdf



Ooops! After posting this I see that Joe had already provided it.

Dave in QCA

Answer to Original Question

Yes, there is no reason that you could not remove this device if you are controlling the pressure with a vaporstat. However, most of us would agree that old working original components don't need to be removed.



If you do decide to remove the old beast, please let me know. I'd be interested in purchasing it.

Thanks,

STEAM DOCTOR

Links

Thanks Dave and Joe for the links. Real eye opener! If I do remove it there is no way in the world that I would sell it. Going into my collection. You are always welcome to come visit. I don't mind sharing my toys.