f ant t trap

Timco

What he said. I have only sized these things by the supply house method..."what pipe size?"


Tim

Jay Beuoy

f and t trap and steam vent

Two questions:

How do I pick the right f and t trap and then correctly place it?

How can I tell if a steam vent is bad? This one is really on tight. I can't get it to budge.

Brad White_203

Watch your language mister...

Oh... Float and Thermostatic, never mind...

First thing is to know your load. If the trap serves a piece of equipment such as a heat exchanger, use the total steam or condensate production number.

Traps are sized by a couple of methods, "net at pressure drop" (usually 0.50 PSI differential) and SHEMA (Steam Heating Equipment Manufacturer's Association) which has, IIRC, a 2.0 start-up factor.

But you have to start with a known load.

If used for pipe and header drips, you have to calculate the warm-up load. Now, to be conservative, I take the total area of the pipe wall x 240 BTUH to be conservative, because that first cold start will condense like that. After that, the insulation keeps the pipe warmer and condensate drops to about 1/6th of the cold-start number.

Now, to be fair, a 3/4" F&T trap (Tunstall TA-FT3-15 to be specific), will pass 369 pounds of condensate per hour at a 0.50 PSI differential. This is more than enough to heat two large houses, so for a pipe drip application, 3/4" usually is plenty. In fact, we often specify unit prices for full 3/4" F&T trap assemblies to be used as required. The sizing is that flexible.

A steam vent, (I assume you mean an air vent or air valve) would be considered bad if it:

1) Does not pass air during steam production and the vent is cold.

2) Passes air during steam production when cold, THEN passes steam when the vent is hot...

A "good vent" passes air readily then closes upon seeing steam.


Now, if you cannot get the vent to budge, none of this information really matters then, does it?

Have you tried a wrench? :P

If yes, get a bigger one. And WD-40.

Jack_44

Try PB Blaster rather than WD40

PB Blaster seems more effective than any other penetrant I've tried.

Jay Beuoy

p blaster

I was wondering about that. I hadn't used any penetrating oil because I was worried about mixing any oil into the water. I guess you are saying that a little won't hurt it?

Jay Beuoy

that was a very technical answer but good I'm sure

Brad,

I had been told that an f and t trap on the main return would move air faster and allow steam to reach the whole system faster. I have problems heating my third floor. The pipe is 1 and 1/2 inch. I think the whole system doesn't exceed 15lbs of pressure. Is that enough info to know what kind of trap? Knowing loads, etc. seems beyond my knowledge and skill set.

Jay Beuoy

the size is 1 and 1/2 inch.

Brad White_203

Thanks, John

I perhaps use the term "WD-40" to mean any penetrating lubricant but always nice to know about new (new to me) products. I will get some. I will not leave it on the night stand unlike the last time...

Mark Custis

If you are worried about oil and

The stuck part is in a cast fitting try adding some external heat.

Brad White_191

The trap size I gave

is the smallest and will serve you well, Jay. That is why I mentioned that it would handle two or more houses.

The F&T's work with a float (to get rid of gobs of water) and a thermostat, to get rid of gobs of air. Between the two of them, you are covered!

You can also get F&T's with side tappings for advanced air removal or can cut in vents upstream of the trap if you are concerned.

My presumption in all of this is that you have two pipe steam though. Correct?