steam trap question

Bill_12

I am installing 300 ft of 1 1/2" 85 psi insulated steam main, all horizontal with 1" in 20 ft fall in direction of flow. A clean run with no takeoffs. Installing end of main trap. Is an additional trap needed at midpoint of piping run?

Unknown

You're pushing it.

When it's cold pipe, you may want to heat it up slowly by hand, but running, it would keep up.

What is it on?

Noel

Tony Conner

I Think...

...you'll be OK from a trapping point of view. I've run 400 feet between main line drip traps. The tricky bit will be dealing with the expansion allowance. You'll likely see the line grow 4 or 5 inches as it comes up to temp.
What you don't want is for the little trap line to get stretched or squashed by the expansion of the larger pipe. Try to install the anchor at the end of the run, along with the trap. Have the expansion joint or loop at the far end. Keep the expansion movement away from the small diameter trap piping. I've seen a few hundred feet of 6" 10 PSIG line expand enough that it put a dandy kink in the 1/2" trap piping.