steam valve limit issue

RJR

I would tend to agree, remember that there is a steam valve in the supply main, forgot to mention the check valve onb the return side, air pressure in the steam chest of the boiler. Heat the water and the air expans to the steam chest thus creating pressure. Crazy but true. Back to my question, any suggestions on the size of the by-pass

RJR

steam valve/limit

Burnham IN6 steam boiler with 2 1/2" screwed main and dual 2" screwed risers to header. 2 1/2 steam zone valve in supply to 2nd floor steam side of system, because the old system had one and th ehomeowner wanted one. Flat plate exchanger on the water end of the steam boiler feeding water radiation on the 1st floor of the home. That a description of the system. Now the fun
Call for heat water side only, steam valved closed, boiler fires and trips the steam limit @2 PSI, causing water temp to flatplate at only 135 -145F. Temps fine going to flatplate with steam side calling, 209F. My thought is run a by-pass around the valve, how ever will I have a high volcity of steam creating noise if I use 3/4", I don't think so since I won't really be making steam, just moving air? Any thoughts

RJR

steam valve/limit

Burnham IN6 steam boiler with 2 1/2" screwed main and dual 2" screwed risers to header. 2 1/2 steam zone valve in supply to 2nd floor steam side of system, because the old system had one and the homeowner wanted one. Flat plate exchanger on the water end of the steam boiler feeding water radiation on the 1st floor of the home. That a description of the system. Now the fun
Call for heat water side only, steam valved closed, boiler fires and trips the steam limit @2 PSI, causing water temp to flatplate at only 135 -145F. Temps fine going to flatplate with steam side calling, 209F. My thought is run a by-pass around the valve, how ever will I have a high volcity of steam creating noise if I use 3/4", I don't think so since I won't really be making steam, just moving air? Any thoughts

Brad White_9

Making steam

and only getting 135-145F water?

A miracle! Saves me a trip to Lourdes

Seriously wondering how you could be getting any pressure below steam temperatures. Your water-side limit should be about 200F (as you know). May be a bum pressuretrol?

Long Beach Ed

Brad's on it there...

... Are you sure it's shutting off on steam pressure?

Sounds like an aquastst is turning it off. Otherwise it wouldn't be making steam either.

There's no water anywhere in the boiler that cold when the thing is producing steam, and if the pressuretrol was bad it wouldn't be steaming.

Sure you're really getting water in that heat exchanger? Or is the 140 degrees coming from hot empty pipes?

Long Beach Ed

John H.

Air expantion

Just add a return line vent to the boiler it will vent the air at low temps and shut when steaming.

RJR

did that shuts off at 2PSI

John H.

Air

Are you steaming the boiler durring the call for the hot water zone or do you have a 2nd aquastat controlling the boiler at a lower temp for the hot water loop. The steam vent will not close unless there is steam.

RJR

The boiler is not steaming on a call for water heat. I would agree with the vent not closing, that is why i installed the vent, it should have worked, the result was the same. It has since been removed. There is a aquastat acting as a high limit off the aux. contaact of a R845A which fires the boiler through the aquastat and turns on both pumps.

Long Beach Ed

Hi Limit

Doesn't that aquastat have a high limit that will fire the boiler up to a certain temperature when the pumps run and then shut off the boiler?

Adjust that high limit setting.

I wouldn't wire it so the pumps ren and the boiler fire together, but thats another story.

Just check for the aqustat high limit. Thats what determines how hot the boiler is allowed to get for the pumps.

Long Beach Ed

John H.

Why

Do you need that check valve in the return maby you can pull the check and give you additional room for expantion.
But at 2 psi may raise the return water line about 5ft. I guess it depends on the hight of the lowest return.

Or how about a steam trap piped to a tee under the return vent on the steam system dry return. this should act simmilar to a bypass around the steam valve.

RJR

LBE
The aquastat is the high limit on the water side of the boiler and is set for 190F, setting at 240 the max, the result is the same. I need the pumps running for both sides of the flat plate

RJR

to hell with it, i'm putting a by-pass around the valve and will report back