One pipe system Bridgeport, CT - Sts. Cyril & Methodius Church

jfice13

Hello all!

I am volunteering to help the Pastor of Sts. Cyril and Methodius Church in Bridgeport, CT to fix his ailing one-pipe parallel flow steam system. They don't have much money and I volunteer there on a regular basis fixing things and doing general handy-work etc.

I believe I have finally figured out how the system works and have been working at coming up with a plan of attack. Based upon when the church was built 1907 (I believe) and the main style of radiator in use (column), I date this system somewhere between 1907-1930. Is this a reasonable guess?

The first attachment is a radiator inventory spreadsheet. The net sq. ft. radiation for all of the radiators is 1427 sq. ft. Currently, the system is being fed from a Weil-McLain 680 commercial steam boiler which is rated for 1983 sq. ft. of net steam. The 580 would have been the proper size it appears, but oh well !

The system is piped with two mains. One main (#1) runs 100' down the length of the church directly out from the boiler room. The other main (#2) runs 50' ft over to the opposing wall, 100' down the length, and then 50' back over to meet the first main where they both drop down into the wet return back to the boiler room. The main vents are installed directly above the drops to the wet return at the end of each steam main. I have attached some pictures of the setup. Main #1 is on the right in the picture. Main #2 on the left.

The venting setup is really cheesy. It appears to me that there is a Hoffman #75 on main #1 (which is 100' long) and some drilled and tapped a 1/4" hole into main #2 (which is 200' long). Main #2 should be vented at twice the rate of Main #1 and yet it's completely backwards. I don't know what the best plan forward is for the main venting solution. The church really doesn't much money so I was thinking of using a bunch of Maid-o-Mist D vents in an antler configuration. I'm unsure as to what to do with the drilled and tapped 1/4" hole vs the 1/2" hole on the Hoffman 75.

Finally, I calculated radiator vents based on my arbitrary choices of 3 oz. steam and 5 minutes based on the Gill and Pajek document. This I have also attached.

My plan of attack for now is:

1) Figure out something for venting the mains correctly *really need help here with ideas*
2) Replace all of the radiator vents according to the sizing in my spreadsheet
3) Turn down the Pressuretrol for a 0.5 psi cut-in with a 1psi additive differential
4) Replace thermostat with a Honeywell digital set to 1 CPH
5) Monitor

I appreciate everyone taking the time to review my spreadsheets, calculation and pictures and pointing me in the right direction. Thank you!

John

Hap_Hazzard

You'd need a LOT of MoM vents to do the job, and if just one of them goes bad, you have a leak in the main. I'd go with Big Mouth vents. They're $85, but you'd need a lot fewer of them, and they're very good vents. You can even take them apart and fix them if they go wrong. I'm not sure exactly how many you'd need, but they have a higher venting capacity than a Gorton #2.

Hap_Hazzard

Here's some product info I found:

The Barnes & Jones 3/4" NPT air vent is designed for maximum evacuation of steam mains used in single pipe steam systems. The large 5/8" orifice provides 3.6 CFM of airflow at only 3 ozs of pressure. The bronze diaphragm has been tested to 10 million cycles and is repairable with a new disc. Overall height: 4 3/4"

Steamhead

What pipe sizes are those two steam mains? This info will help us determine what venting you need.

Drilling and tapping for main vents like that is a very popular way to upgrade a steam system. We do it all the time, and I ran into two systems this week where someone had done it before. In these cases I upgraded to bigger tappings and vents.

If a lot of venting is needed, welding thread-o-lets on the pipes is a good way to go. See our company's Find a Contractor ad for one job where we went that way.

jfice13

Thanks @Steamhead - I was thinking about getting a thread-o-let welded on.

I believe the mains are 3-1/2" but I will double check on Sunday.

Jamie Hall

Yes. Big Mouth vents. They can go on antlers; I'm thinking two and three, but the other folks are better than I am at that. Your pressures look right.

A Honeywell digital should work well for that -- but a couple of thoughts. People in churches like to mess with thermostats (ask me how I know) -- so put it in a lock box. Give a key to the Rector, and one to whatever the equivalent of the Junior Warden is -- and nobody else. Oh. Keep one yourself. Then really think about your program. They will want to keep the heat down during the week -- but as we all know steam takes time to get up to speed, and so do sanctuaries, no matter what kind of heat. So I suggest that for Sunday at least you set the thing so it starts to come up to 70 or so on Saturday night. Play with the start time for the ramp up, but trust me: get it set so that when the congregation starts to show up Sunday morning it's nice and warm in there. The rest of the week -- depends on what they've got going on (one church I do has something pretty much everyday; another one Sunday only).