Checked Your Pigtail Lately?

Long Beach Ed

Pressure controls are usually mounted with a curled steam siphon "pigtail" loop to protect the control from steam.

Most of the ones we check are clogged, rendering the pressure control useless or inaccurate.

Blow through them and make sure they're clear, otherwise your boiler can build way too much pressure, wasting fuel and relying only on the pressure relief valve for overpressure safety.

Steel pigtails rust and clog easily; brass ones less so. If yours has been on the boiler for years take care not to break it off at the threads by exerting too much force to remove it. It may very well be rusted into place.

You'll have a job clearing it out with a wire, water and pressure. If it can't be cleaned it must be replaced.

CaptPaul

What a coincidence. I am sitting in my basement with my tablet waiting for boiler to cycle a second time after cleaning out my severely clogged pigtail. On the initial startup after the cleaning the unit cut out at 2.5 psi when it had been running up to 5 psi. The high pressure is what prompted the cleaning. Hissing in my radiators also seemed to be quite a bit less which I guess would be expected. Waiting for it to cycle again to double check but it sure seems like it worked.

ChrisJ

Such a shame we're forced to use a pigtail instead of an air gap which doesn't clog.

All well. The rules are the rules.

KC_Jones

ChrisJ said:

Such a shame we're forced to use a pigtail instead of an air gap which doesn't clog. All well. The rules are the rules.

It’s also a shame the pressuretrol is being utilized as a control because so many boilers are oversized.  Its primary function is a safety device, using it as a control is a cover up for improperly sized boilers.

Talk about waste.

ChrisJ

KC_Jones said:

ChrisJ said:

Such a shame we're forced to use a pigtail instead of an air gap which doesn't clog.

All well. The rules are the rules.

It’s also a shame the pressuretrol is being utilized as a control because so many boilers are oversized.  Its primary function is a safety device, using it as a control is a cover up for improperly sized boilers.

Talk about waste.

You mean people that think a steam boiler bouncing off the high limit like this is "normal" ?

Hap_Hazzard

It's on my annual start-up checklist.

Kickstand55

Some need to be checked more than once a season depending on how much crud makes it way into the loop. I install brass unions with brass piping with the brass pigtail. Works sweet. Easy to service.