Replacing Boiler in Vapor System

Jon Slater

My boiler is being replaced. I have an old Moline vapor/vacuum system that was operating in a vacuum. In reading Dan's books and articles I'm led to believe this system should be set up as a low pressure system. Is this correct. Any thoughts or tips. Also, the old Moline orificed supply valves have long been replaced by standard Hoffmans that the last owner said "were set, dont mess with them". Are orificed valves still available? Thermastatic versions? Thanks!

Unknown

Yes, yes, yes, yes, and yes.

The answer is.....

Tunstall.

http://www.maconcontrols.com/tcorp.html

http://www.maconcontrols.com/inletorifice.html

They offer orifices, valves, and TRVs.

A vaporstat, L 408 A 1132 will keep the pressure low.

You have a wonderful system with very few moving parts, never let anyone convince you that it should be torn out.

Noel

Mad Dog

Hey Noel

send me your email please....haven't got thru in a while. Mad Dog

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Boilerpro_3

Yep, great systems

I get to work on them fairly often, being that I am only an hour from Moline in northern Illinois.

Boilerpro

Steamhead

Vapor was the Cadillac of heating in its day

and is still one of the best systems out there. And the Moline was one of the best Vapor systems ever installed.

Make sure you keep the old vacuum-producing pieces- they will be very useful if we go back to using solid fuels.

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Jon Slater_2

Thanks for the valve info!

Jon Slater_2

old pieces

Does the vacuum injector need to come out? Can we get it into pressure by replacing the main air vent with one that does'nt have a check valve? Thanks for your help I have'nt been able to find a steam guy in town.

Jon Slater_2

Moline system

I love the system and appreciate the art to maintaining it. Question I have is can I get it to low pressure by merely replacing the main air vent with a non vacuum vent? Thanks!

Boilerpro_3

The ejector stays...

It's purpose is to rapidly remove air from the system as vapor is produced by the boiler on start up. Once the air is removed the check valve on the air vent would close, and when the coal fire would die down, a vacumn was created as the remaining vapor condensed.

Leave the ejector in place along with the condensor pipe or radiator. If you install a vaporstat and set it for below about 8 ounces pressure max, an air vent at the end of the condensor is really not necessary as the steam will never get that far down the condensor pipe! It only served as a back up should the pressure get over 8 ounces.

Where are you located? Have you tried "Find a Professional" here?

Boilerpro

Jon Slater

Vacuum valve

I'm in Lancaster OH and find a pro gave me a one good outfit 70 miles away. I believe I have a good contractor, strong recomemdations locally, and he is willing to listen to me (poor guy) and you. In reading the steam heating companion I see that originally the system had a Moline Air Relief and vacuum valve that have since been replaced by a Hoffman #76 Main Vent Vacuum Valve. When the old boiler burners shut down the Vacuum Valve would close and put the system in a pretty good vacuum and produce vapor. The way the system was designed originally I guess. I'm thinking that to operate in low pressure I need to loose the vacuum valve and use something different. Does that make sense? Any recomendations? Your help is greatly appreciated. Thank you.

Boilerpro_3

You're right on

Get rid of the vacumn valve. The on/off nature of modern steam boilers tends to not work well with vacumn systems, so you just run very low pressure.
AS above, just an open piece of pipe can work in place of the vent.

Boilerpro

steve_6

orificed adjustable radiator valves

Marsh R-105 is the only one I've seen. here is the web address. http://www.marsh-heating-equipment.com/adjustable_oirfice_valve.html