Vapor System Componets and Operation

Ernie

001 Weil-McLain 572 Net I-B-R Rating , steam Sq Ft 915, 219,1000 BTU/HR

001 Trane Valves are at end of each Main and Return. One Main is 27' long the other is 33' long.

003 Drip Traps are off end of each Main.

006 Trane B2 traps,there are 11 all repaired and are connected to Fin Tube Emitters buried in walls and can not
be seen

005 Sarco Trap serves 1 CI radiator 57" long,16" high,4" wide. 38 sections. There is another 12' long Fin Tube
emitter that has a similar Sarco and is wall mounted like
baseboard.

007 Trane Direct Return just sits there.

010 Check valves do not have flappers..... Should they be
replaced?

017 Heating Vent is located at 6' level above floor. Good for heating ceilings!

018 Baseboard cut out to supply air to Fin Tube Emitter buried in the wall.

System operates with 0-16 oz vaporstat set a 12oz Main, 8 oz Differential subtractive. Problem was short cycling prior to repairing traps. Sarcos have not been touched. Boiler is maintained at 180*F for HWBB loop off tankless coil. With this set up it will produce steam in 15' on call for heat with a Mark I Interburner firing a 1.25 x 60* W Delavan nozzle, and will continue to run till T-stat is satisfied. Larger nozzles 1.35, 1.50, 2.00, cause short cycling, producing steam faster that system can condense it. At least this is what I have observed , a lot of basement time. One peculilar observation when system shuts down it goes into vacuum.

What have I done right/wrong or should change,aside from replaceing boiler which I believe is oversize













































































































.

Unknown

Vapor system

Replace those chek valves. These check valves prevent the water in boiler from entering the return lines. Look very carefuly at the vertical piping between those check valves. I donot know what is there so I cannot advise further.

I do know what should be there. My guess is that the system has a dry return and a wet return. You may have a hybrid vapor system because you have vent valves at the end of the steam main where the horizontzl piping goes to the vetical drop.

Typically a radiator trap is installed at the end and the discharge is piped to the dry return. The dry return ends near the boiler where a vent chamber and master vent valve is placed.

The old vapor system went into vacuum when the boiler stopped producing steam. These systems were designed to operate with a coal fired boiler.

When the boilers were converted to gas or oil the systems operated differently.

Because the the fuel supply was on and off the steam systems cooled much faster than coal fired boilers.

In some older systems the vent valves had to be changed to prevent vacuum from occuring. Vacuum in some of these systems caused many different problems.

Many of these older systems operate well with vacuum. if your system produces vacuum and you do not have banging, erratic boiler water levels that cause short cycling leave it as is.

You stated that you derated the burner because the boiler was making steam to fast, taht may be so.

I think that the check valves with out the flaps caused your problem. When a burner fires at full capacity in modern boilers the steam pressure can rise above the set point after the burner has shut down. If the steam pressure rose high enough and the dry side of the steam main was resonably low the water from the bloiler could be pushed into the steam main, additionally if the steam system was tight and produced a vacuum abve 4" Hg the water in the boiler can be pulled up 4 feet in to the piping at the end of the steam main. If the water level in boiler is at 36" off the basement floor you will have water in the steam main.

The flaos in the check valve prevent the water from being pushed or vacuumed out of the boiler.


I tried to keep it simple, maybee I rambled a bit but to explain the old vapor systems to you I would a few drawings and about three pages of text or a drawing and a half an hour talk time.


Jake

Ernie

Check Valves

Thank you for your reply. Will replace check valves, verticle pipe to the right goes to the Direct Return Trap, the pipe on the left is the Hartford Loop, copper pipe is capped off and serves no function. Boiler waterline is 47.5" of the floor.

Ernie

Check Valves

Thank you for your reply. Will replace check valves, verticle pipe to the right goes to the Direct Return Trap, the pipe on the left is the Hartford Loop, copper pipe is capped off and serves no function. Boiler waterline is 47.5" of the floor.

Steamhead

I agree with Jake-

replace those check valves! The Direct Return Trap can't work without them. The Vaporstat is great but the Return Trap is your backup if the pressure should get too high.

The system goes into vacuum because of those vents. I have a few sitting around my house that came off various systems- each of these vents is comparable to a Hoffman #75 or Gorton #1 (non-vacuum) or Hoffman #76 (vacuum). You really don't need to run vacuum when burning oil or gas- and since those vents were sized for a coal system they may be too small. I've had good results with Gorton #2 vents on Vapor jobs- a #2 has about 4 times the capacity of the vents mentioned above.

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Ernie

Vents

Would you put the Gorton #2 on both the Main and Return or is it sufficient to just put it on Main? My system would require 4 Vents as their are 2 mains leaving the boiler, and 2 returns paralelling the mains. Once steam is produced the Mains heat up very quickly. Reference vacuum both the Trane Quick and Float Vents have the aluminium discs removed from underneath the caps, and the system still goes into vacuum on shut down.

Ernie

Vents

Would you put the Gorton #2 on both the Main and Return or is it sufficient to just put it on Main? My system would require 4 Vents as their are 2 mains leaving the boiler, and 2 returns paralelling the mains. Once steam is produced the Mains heat up very quickly. Reference vacuum both the Trane Quick and Float Vents have the aluminium discs removed from underneath the caps, and the system still goes into vacuum on shut down.

Ernie

Vents

Would you put the Gorton #2 on both the Main and Return or is it sufficient to just put it on Main? My system would require 4 Vents as their are 2 mains leaving the boiler, and 2 returns paralelling the mains. Once steam is produced the Mains heat up very quickly. Reference vacuum both the Trane Quick and Float Vents have the aluminium discs removed from underneath the caps, and the system still goes into vacuum on shut down.

Steamhead

Those aluminum discs

are only part of the vacuum-holding mechanism. There's a diaphragm in the bottom of the vent that holds the float up during vacuum- this is undoubtedly what's causing the system to hold vacuum.

If the mains are heating quickly, try the Gorton #2 vents on the returns.

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Unknown

Vacuum

This is what we had on the big job we just finished . Kinda bright - but the gauge reads it was in vacuum .

Ernie

guages

> This is what we had on the big job we just

> finished . Kinda bright - but the gauge reads it

> was in vacuum .

Ernie

Gauges

Yours is nice,new and bright