Old vapor system and orifices

Unknown

I'll get back to you.

Noel

Frank Weigert

I have an house with an old vapor system (ADSCO) that was discussed in a previous threat last month. Some of the original radiator valves have been replaced with new ones. Unfortunately the old ones had orifices and the radiators have no traps. After going through every local plumbing supply shop on the search for orifices (in most cases people had no idea what I was asking for), I finally asked a friend with a metal shop to make them for me. He is going to make all the plates with a 1/8" hole which based on some of the old valves I still have should be right for my smallest radiators. Are there any charts or formulas that can help me to determine (based on radiator size) how much I have to drill out these openings for my larger radiators ?

Frank Weigert

Steamhead

I think this is what you need

2 inches of vacuum equals about 1 PSI. Use the far-right column for Vapor, and add a Vaporstat to keep the pressure at 8 ounces or so. This comes from one of my old ASHVE Guides.

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

Frank Weigert

Thanks Steamhead,
just to make sure that I read this right. Based on the chart an orifice with an 1/8" (8 64ths) hole would be right for a radiator with 8-11 square feed EDR in a vapor system, correct ?
A quick question about the Vaporstat, there are two modesl for 4-16 ounzes, the L408A1132 (switch breaks on pressure rise) and the L408B1131 (switch makes on pressure rise). My instinct tells me I need the L408A1132, or am I wrong ? I have a Crown boiler from 1995.

Thanks

Steamhead

Right on both counts

Also, Tunstall makes very nice orifice disks if your friend's efforts don't work out. Their site is

www.tunstall-inc.com

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

Frank Weigert

Thanks again Steamhead