Mystery Hoffman Valve

L'town Radiant_2

I have a Hoffman valve that my rep doesn't seem to be able to help me with. The valve says that it is a No. 11 Vacuum valve. I figure this is either a vacuum breaker or a main vent on a vacuum steam system. I know that this is on a  low pressure steam system, but I wasn't on site to see where it was installed. Can anyone confirm or clarify?

DanHolohan

Here you go.

http://www.heatinghelp.com/files/articles/1306/310.pdf



It's in the site's Library. It's a main vacuum vent for a vapor-vacuum steam system.



It pays to wander off the Wall.

Paul Fredricks_3

here you go

According to Gill and Pajek's sheets, it's a Hoffman #11 main vent rated at 2.410 CFM at 2 oz pressure. Love that book.



http://www.heatinghelp.com/products/Books/5/146/Balancing-Steam-Systems-Using-a-Vent-Capacity-Chart-by-Gerry-Gill-and-Steve-Pajek

Steamhead

That vent was used

on the original type of Differential Loop. If it needs replacing, a couple Gorton #2 vents would work.