Steam Valve type

Homeowner

How do you tell if a steam trap has a removable seat or an integral seat? I need to know in order to buy a replacement core for a #8 Hoffman steam trap.
Thanks.
Steve

Steamhead

If you remove the top of the trap

and take out the old element, and you see just a hole in the bottom of the trap body that the element extends into to close the trap, that's an integral seat. But if there's a hex-head around the hole, you can put a socket wrench on it and remove it.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Homeowner

Thanks alot Steamhead. This is the first time I have ever had to deal with steam heat. I apparently have 4-5 steam traps not working. I have learned quite a bit looking on the internet. I have two books on the way, also. I am still not sure this system was plumbed properly right from the start. It is probably 50-70 yrs. old with a new boiler installed 4-5 yrs. ago. Thanks again,
Steve

Jim_22

Hoffman 8

According to my Barnes & Jones Steam Trap Repair Guide the Hoffman 8 was made with intregal and removable seats. I think you will need to open it up and look inside. Once you remove the cap (make sure steam is off) and the thermostatic element you can look inside. If it is a removable seat, you will see a nut that a socket will fit on. One more warning, some traps can be a little difficult to open. If you use too much force the wrong way, you can wreck the trap or return piping. If it gives you a fight, you might want to call someone who has done it before.

Hope this helps,

Jim

Homeowner

I've gotten the caps off already but I wasn't sure what I was looking at. Now I know, thanks to you guys. I wanted to replace all of the elements in the house. Over the years someone has installed steam vents on 5 of the radiators, apparently to get them to heat up. I have read several articles on why not to do this on a two pipe system which led me to drain all of the radiators. The whole thing started because one radiator didn't get hot. when I took the cap off and fired the boiler it got hot but steam was also coming out of the drain hole in the trap, which led me to check all the others, and on and on and on. One thing I'm curious about is the ends of both main steam lines are connected directly to the return line. Just before the connection (3-4 ft) there is another steam trap (#18 Hoffman) Is this the way it is supposed to be?

tp tunstall

sounds

like a thermostatic drip trap. better repair that one also. the contractor can get those parts. t. p. tunstall

Steamhead

Those #18s are \"crossover\" traps in that configuration

They do the job of main vents, but they discharge into the dry return. The air goes out a vent somewhere on the dry return. If that system has a Differential Loop, the vent is on or near the Loop. If it has a Return Trap, there's probably an Air Eliminator Trap just above the Return Trap.

There should be no pressure at all in the dry return. If there is, you have one or more traps blowing steam into the dry return, or the vent on the dry return is bad.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Homeowner

Hi Steamhead,
I went over there today to check a few things I read about in the book "The lost art of steam heating" that I ordered on this website. There was a newer boiler installed 4-5 yrs. ago, before I bought the house. So I proceeded to check the pipe sizing, the near boiler piping, riser lenght, proper water level compared to the old boiler piping, cut in and cut out pressure, and looked for the end of main vents. I was pleasantly surprised that everything checked out right except for the vents. All the radiators get hot except one long baseboard radiator, but I know the trap is bad on this one. I also took all the caps off of the traps to check what kind of seat they had and boy was I surprised to find four of the eleven traps didn't have anything in them at all!
Also, back in the basement, I have two risers coming out of the boiler. One feeds the back and the other feeds the front of the house, and returns running side by side with them. After the end of the steam pipe drops about 4 ft. it connects to another pipe running back to the boiler about 1 foot off the floor. This pipe is below the water line so I took it apart and flushed it. It was plugged tight. I couldn't find any vents on the dry return or anywhere else for that matter. I'm not sure what a Differential loop is but I do have a rather large object hanging down about 30-36 inches that the dry return runs into. It loops down then back up back to the dry return. It looks like a very large sink drain trap with two plugs in the bottom. Coming out of the top of it is a 3/4 inch pipe, 6 inches long and it has been capped off. Could this be a differnetial loop or a return trap? If so should I put a vent on there and if so what kind or size should I use?
I ordered all new steam traps but I want to make sure everything else is working properly so they dont get destroyed the first week.
I really do appreciate all the help you have given me.
Thanks again. Steve

Steamhead

It might be a Differential Loop

but to be sure, how about posting a picture? We'll know for sure when we see it.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Homeowner

Here is the pic you wanted to see. Notice the pipe coming out of the top. Is this where a vent is supposed to be and if so, what kind? I also included a pic of the steam main connected to the return. Should the connection be below the water line?

Steamhead

Bingo!

That's a Differential Loop all right- someone covered it with asbestos, first time I've seen that. You'll find the label on the upper portion when the asbestos comes off.

The capped 3/4-inch pipe originally had a Hoffman #11 vent on it, the biggest ever made that I know of. It had the capacity to vent all the radiators in the system as well as the steam mains. The #11 vent is long since out of production, but the Gorton #2 vent works very well on this type of system. Note that this is the only air vent on the entire system, which explains why you've had trouble getting heat in all the radiators and also why there was pressure in the dry return. If the air can't get out, the steam can't get in!

Obviously those radiator vents don't belong there. Get some 1/8" plugs and install them in place of those vents. Watch how well the system works with the traps repaired and the Gorton #2 on the job. If the air rushing thru a single #2 is noisy as the system is heating up, add a second one for more venting capacity. I have several large Vapor systems out there that have three #2 vents on the dry return.

Note that we've had some cases where excessive heat in a boiler room has caused Gorton #2 vents located therein to close prematurely. If the boiler room gets much over 100 degrees, you're wasting a lot of heat as well as affecting the vents. Insulate those bare steam pipes!

If you have trouble finding Gortons in your area, call Gorton at (908) 276-1323. Talk to Ken Kunz and tell him I sent you.

The ends of the steam main and dry return do connect together, and the connection should be below the boiler water level. No steam can pass into the dry return this way.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Homeowner

I have removed all but two steam vents from the radiators. I left them on till I get the new traps in place. The one rad that wasn't getting hot was a stuck closed steam trap. Four other radiators didn't have a trap inside the housing. I have all new traps on the way. My next project is to replace all the broken adjustable modulating valves on the radiators. I'm sure when I get the system working properly there will be rooms getting too much heat. I will get a new main vent and put it on the differential loop. Should I remove the asbestos from the differnntial loop? If you look closely at the "steam & return jpg" there is a line on the asbestos on the return about 2-3 inches up from the bottom tee. That is the water level from the sight glass on the boiler I transferred over there, using a laser level, when the boiler was firing. Would the water level raise enough from the back pressure from the boiler to submerge the steam main to return connection or should I lower this connection to get it under water?
The boiler is in the basement and it doesn't get excessively warm down there but I will insulate any steam pipes that aren't covered now.
The system heats the house quite well other than the high fuel bills, as you can well imagine. I just refunded $230.00 of the rent for the last three months due to the high bills. I don't normally do that but my tenant is also my ex brother-in-law and a good friend. I just compared it to my own heat bill. Not very accurate, I know but had to do something. Thanks again.

Steamhead

When you go to fix those radiator valves

contact Tom Tunstall of Tunstall, Inc. The URL is:

www.tunstall-inc.com

They can supply parts for almost any old radiator valve.

The water level in the drips to the wet return should be OK as long as it stays above that tee. More water will back up into the drip from the dry return ("B" dimension) than the one from the steam main ("A" dimension- both dimensions are covered in Lost Art book) but this is normal. The important thing is that the tee is under water.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Homeowner

I found a supplier in town here but all he had was a Hoffman
#75 main vent so I got that. I need clarification on a couple things.
The tee from the steam main to the return is NOT below the waterline when the boiler is NOT firing. It is about 12" above the waterline when not firing. Is this o.k. as the "b" dimension will raise the waterline and submerge the tee? Also, there is a gravity flap check valve on the wet return at the boiler. Should I remove this to allow the water to back up and submerge the tee? I also have two pressuretrols that appear to be wired in line, as if one fails the other will control the pressure. With both cut-ins set at the lowest they will go the burner fires at 1 1/2 psi. Should I have a vaporstat on here instead?
Thanks for all your help.
Steve

Steamhead

\"but all he had was a Hoffman #75\"

SSOOOOOOO typical. If that 75 isnt enough, call Gorton at (908) 276-1323 and they'll sell you a #2 direct.

That check valve works with the Differential Loop to make sure water returns to the boiler properly.

When the steam is up, check to see if any steam is getting thru the tee connecting the drips from the steam main and the dry return. If not, you're OK.

The usual PA404 pressuretrol isn't that accurate. But neither is the usual pressure gauge. Try another gauge, since it's a lot less expensive than a Vaporstat. If you want to get a Vaporstat, there's no need to get two. The remaining Pressuretrol can serve as a backup.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Homeowner

I replaced all the steam traps and installed the main vent yesterday. It seemed to work o.k. at first glance but the main vent closed long before the radiators got hot. Should they get hot all they way across right away? It took them about 45 minutes to get hot and some of them never did get hot all the way. What I'm thinking is that the steam got into the dry return and closed the main vent before the water raised enough to block the tee between the steam main and the dry return equalizing the pressure throughout the system. Do you think that's what is happening? I looked at the tee in question and I can repipe it without too much trouble, other than the asbestos covering the pipes. How much risk is involved in removing some of the asbestos myself, or should I call someone to come in and remove it for me? I only need to remove about 24 inches total.

Steamhead

You really need a licensed asbestos contractor

to do that. In some locations this is required by law.

The alternative to repiping that tee is to build a False Water Line. You can do this at the boiler, where there probably isn't any asbestos. Dan covers this in "The Lost Art of Steam Heating".

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Homeowner

I looked around the boiler and to my surprise, the installer of the new boiler already installed a false water line. The only problem is he didn't make it high enough. My question is, how high should the water line be above the tee between the end of steam main and the dry return in order to keep the steam out of the dry return?
Thanks,
Steve

Steamhead

Good question

I would say at least a foot. Better yet, make it as high as you can without compromising your "A" and "B" dimensions. The "B" dimension is greater, so if you can, leave a height of 30 inches between the false water line and the lowest point of the dry return. The Differential Loop will make sure the water doesn't back up into the dry return.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Homeowner

The best I can get is about 4 inches. Will that be good enough?

Steamhead

Probably

Where does that leave your "A" and "B" dimensions?

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Homeowner

The "A" dimension would be 31" and the "B" dimension would be 45".

Homeowner

I went ahead with what I had and I am sitting here in a nice, toasty, warm house. All the radiators are HOT all the way across. All the returns are cool to the touch so I'm not losing steam to the returns. The main vent was releasing a ton of air before I raised the false water line but now it is just puffing away, nice and gentle.
I think I have finally finished this job. Notice when this thread started (12/22/03). It only took me a month to get this system up and running properly. Not bad, huh. I think I'll go into the steam system diagnosing and repair business!
All kidding aside, I couldn't have done it without the priceless advice and expertise of Steamhead and all the knowledge I have gained from Dan Holohan's book, "The Lost Art of Steam Heating". Thanks alot everyone here and especially to you Steamhead. This is a fantastic site.
Steve

Steamhead

That's more than enough

for both. Build the FWL higher if you can. The Differential Loop operates at 10 ounces pressure, which is a little less than 2/3 of a pound. So theoretically you could have a 20-inch "B" dimension with no problems, but I'd give it 2-3 more inches to be safe.

The original boiler's water line was much higher than the one you have now. I'll bet the original "B" dimension was lower than the 30 inches we try to get now.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"

Steamhead

Can't argue with success!

Glad to help.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Contractor"