Heating Help

The Float Trap/Air Eliminator

@ April 28, 2012 11:21 AM in OK What is it

IS the air vent. It is an open pipe, with a float to close the opening if water backs up that far.

However, it may be stuck, or may simply not be big enough to vent the system quickly with the use of oil or gas firing. A coal-fired boiler came up to pressure slowly, but with oil or gas the steam comes up much more quickly and the air venting has to keep up.

There may have been a vacuum check where the Hoffman air vent is now. That was another coal-era trick- as the coal pile burned down, the air couldn't get back in, so the system kept producing steam at lower temperatures. On oil or gas, the system often shuts down before all the air is out, resulting in uneven steam distribution under vacuum.

Even if the Return Trap is shot

@ April 27, 2012 11:40 AM in OK What is it

you do NOT need to install a return pump.

Remember, this was installed during the Coal Era, when it was more difficult to control the boiler pressure than it is now. Today we have a simple device called a Vaporstat, which can stop the burner at ounce pressures. As long as the pressure is kept low enough that the condensate can return by gravity, you don't need to pump it. And a return tank and pump, plus the additional traps that would be needed, will create more service headaches down the road. I repeat- you don't need a return tank and pump.

Listen to the Dead Men. They were geniuses.

The procedure for checking the Return Trap is outlined in chapter 15 of Lost Art. Basically, if steam goes into the Return Trap as soon as the boiler starts steaming, the internal valves are leaking. But if needed, I believe Tunstall can rebuild a Return Trap- call them and ask for Woody Tunstall, and tell him we sent you.

The air vent is another matter, though it is related. Vapor systems like this were designed to run at less than 1 PSI. But if the air can't get out at that pressure, the boiler will run and run, building more pressure than is needed to distribute the steam against the friction loss of the pipe. If that Hoffman is the only air vent on the system, it's way too small for a system of that size. A vent that is too small will slow the steam distribution and waste fuel.

Where is this system located?

Henry, your quote is spot-on

@ April 26, 2012 11:42 PM in A. O. Smith Cyclone Xi Field Performance

"They discovered that due to sediment in the tank, the welds of the flue pipes would fail causing the leaks. It was not perforation due to a glass lining failure. It was stress cracks due to the sediment collecting and insulating the weld from the water."

The sediment comes from the water lines in the street. In older cities these can be over 100 years old. Most customers don't blow the sediment out of the tanks. Not only does this shorten their life, but also reduces their efficiency.

When we replace a water heater, we recommend a sediment filter (minimum size 4-1/2x10) and install it on the water service just after the main valve (and PRV if used). Once the pipes are flushed out, they stay clean and so does the heater- unless the owner doesn't change the filter or have us do it, but that's another issue. And it's easier to change a filter than to get a couple inches of sediment out of a heater.

It's a Return Trap

@ April 26, 2012 9:50 PM in OK What is it

basically a pressure-powered pump that can force the water back into the boiler if the pressure gets high enough that the water can't return by gravity. The sight glass is used for seeing the water level rise into the Return Trap, and drop when the trap is activated.  See chapter 15 of "The Lost Art of Steam Heating". 

The air vent appears to be mounted on a pipe coming out of a smaller cast-iron device. This is an "air trap" or "float trap/air eliminator". It is the one place in the system where air can be vented (larger systems used several of these). The vent appears to be a Hoffman #75 or #76, and is almost certainly too small for this application. You will likely need one or more Gorton #2 vents there.

At the ends of the steam mains, you will probably find traps connecting the steam mains with the dry returns. These are usually thermostatic radiator-type traps, but can be F&T traps too. Their job is to serve as main vents, letting the air out of the mains quickly so the steam can fill them.

Have you found names on any of these devices? This will help us ID the system. Also, take some more pics of the system and post them here.

Maybe

@ April 26, 2012 9:36 PM in to Steamhead

went to a trade show today and talked to the PowerFlame rep. The usual hookup is a L91 modulating control, but Honeywell no longer makes one that works on ounces. I'm sure we could come up with something by switching fixed resistances with a Vaporstat to produce lo-hi-lo, but haven't had time to play with it.

The Mills

@ April 26, 2012 1:14 PM in Heres a photo of a fairly old boiler :)

was the best boiler of its time, and is still being made. But that one probably wasn't running at its best with that conversion burner.

Is the second Mills a spare?

Chris and GarvinP

@ April 25, 2012 8:49 PM in to Steamhead

Not sure since I haven't called them, but PowerFlame may offer lo-hi-lo firing on the X4-400. If so, that's the way to go- you can drop the firing rate 25-30% or so when you build a few ounces of pressure, which will keep the boiler running steadily instead of wastefully stopping and starting on pressure.

Check with PowerFlame to be sure.

Before you do anything

@ April 25, 2012 10:22 AM in leaky pipe?

check the pipe size and pitch. Determine the size of the radiator and make sure the pipe is large enough to supply it at that distance from the main, and make sure it pitches back to the main as much as it can.

I'm certain the water hammer caused the leak, and you don't want that to continue after the ceiling is closed in.

You might need some help with this. Where are you located?

That guy

@ April 25, 2012 10:01 AM in Boiler put in wrong 3 years ago - Do they owe me?

doesn't know what he's talking about. And if someone trained him that way, which I doubt, that person is equally benighted.

The boiler manufacturer specifies certain minimum piping standards for a reason. They have tested their boilers to make sure they produce reasonably dry steam, and the steam piping around the boiler is one factor in drying out the steam. If the manufacturer determined that 2-inch pipe would work, they would specify it.

That boiler is a Dunkirk Plymouth Series 2, no matter what name is on it. Carrier, Bryant and others re-brand Dunkirk boilers to fill out their product lines. I've included the link to the I&O manual with the piping diagrams- they show the use of either one or two steam tappings, but nowhere do they sanction the use of 2-inch pipe. Personally, on the larger Plymouth steamers I would always use both tappings, to reduce the steam velocity.

They need to repipe it. Period.

http://www.ecrinternational.com/secure/upload/document/2435.pdf

We mostly use Carlin EZ-Gas on the smaller ones

@ April 24, 2012 10:02 PM in to Steamhead

but have used Midco EC series too. Haven't had issues with either, except the Carlin can be a bit loud sometimes. Haven't used PowerFlame on the larger Intrepids yet, but Steam Whisperer has with good results.

I don't see why not

@ April 24, 2012 10:00 PM in to Steamhead

assuming it's one of the larger Intrepids. Which Intrepid are you looking at? 

Looks like a bad gauge

@ April 23, 2012 8:37 PM in Redesigned steam piping...

also have him check the pigtail under the pressuretrol if he hasn't already, to make sure it isn't plugged. 

When we were e-mailing Burnham about that

@ April 23, 2012 1:22 PM in sell me on a power gas burner

whoever responded said they hadn't done any testing yet. I think I still have that e-mail somewhere. I've gotten a few other excuses as well. I'm sure they could get a gas MegaSteam to run at 85% AFUE if they really wanted to.

I think it's a political problem- someone high up at Burnham just doesn't want to do a gas MegaSteam, and is in a position to block it.

Since at least 70% of boiler replacements are gas these days, not offering the truly superior MegaSteam in gas is at best a questionable business decision.

No reason to dump the steam

@ April 23, 2012 1:15 PM in Stay steam? Oil or Gas?

what amounts of radiation do the apartments have? 

At least!

@ April 23, 2012 9:39 AM in boiler choice time

nice work.

Never saw one like that

@ April 21, 2012 9:04 AM in Grundfos pump

are those 2-inch flanges? 

Agreed

@ April 21, 2012 8:28 AM in boiler choice time

so which Buderus did you end up using? 

What exactly

@ April 20, 2012 8:20 PM in Warren Webster 2 pipe vapor system boiler replacement

is leaking on that section? Is it leaking from the top or bottom?

I know where that is

@ April 20, 2012 8:15 PM in Hacked up two pipe vapor system....

if you need some more eyes on this, get in touch- it's a nice day trip from Baltimore.

Take some pics and post them here- let's see what you have.

Where in PA?

@ April 19, 2012 11:34 PM in Hacked up two pipe vapor system....

the Vapor system might be a Kriebel, Richardson, Thermal or some form of Orifice system. It should not have air vents on the radiators- that's a sure sign of knuckleheading.

Find out from Weil-McLain if the 80 series intermediate section really will work in a 78. But even if it will, some other section might be getting ready to fail, so simply replacing a section might be a short-lived (and still expensive) repair.

Also, do a heat-loss calculation on the building using hot-water baseboard- it's very possible that boiler is oversized.

Only three years?

@ April 19, 2012 6:29 PM in What they do in England

He deserved a lot more. 

Why are you tearing everything out?

@ April 17, 2012 5:53 PM in Changing to gas - two bids, which one??

No need for that. If you have a recent model Smith oil-fired boiler, it's probably an 8 series, which can be easily converted to gas using a replacement burner.

You need to find a better contractor, who knows steam. Try the Find a Contractor page of this site.