Pigtail question regarding Gauge on residential one pipe steam

RTW · April 23

The port off front of boiler has a stem that rises up to a Tee fitting. Off to one side it has a pigtail for the pressuretrol and off the other side of the Tee it goes directly into the 1 to 30psi gauge ( that must be 30 years old). The dial has ever moved to my knowledge and the pressuretrol is on the lowest setting - QUESTION: should the gauge have a pigtail since my service tech has never mentioned it even when he last checked the pigtail, which was fine? I know the tech added some water to the pigtail when he re-installed it

Regards

RTW

EBEBRATT-Ed · April 23

Most gauges say on the face that it has an Internal syphon. But mots think for longer gauge life it should be on a pigtail. Use all brass fititings on the pressure trol and gauge and you will have fewer problems.

RTW · April 23

YES, the front of gauge has " internal syphon gauge" printed on it

pecmsg · April 23

That 0-30psig gauge is required by code. Gauges are only accurate when reading in the middle range. With your system operating at less than 2#'s you shouldn't notice any movement.

You can install a 0-5# gauge and isolation valve but the 0-30# must remain.

RTW · April 23

Lastly, is there a way my service tech can test the 0 - 30psi gauge when he returns to service/clean boiler after the heating season or is this an overkill request? Regards, RTW

Jamie Hall · April 23

https://forum.heatinghelp.com/discussion/comment/1799883#Comment_1799883

That's overkill. Odds are that the gauge will read something, anyway, if the boiler pressure gets up in the 5 to 10 pound range, at which point you have other things to worry about. Leave it.

ChrisJ · April 23

Most cheaper gauges that I've seen fall under the +- 3-2-3 category. My guess is the cheap gauges supplied with boilers do as well.

That means the middle 50% is 2% accuracy and below that and above are 3%. It doesn't mean it's not accurate at the extremes, it's simply a little less accurate.

So in the middle 50% of the gauge a 30 PSI gauge is within +-0.6 PSI and at the extremes it's within +-0.9 PSI.

If I did my math correctly.

Mad Dog_2 · April 23

Ya gotta spend a few bucks to get a qaulity Guage today. Mad Dog

ChrisJ · April 23

https://forum.heatinghelp.com/discussion/comment/1799910#Comment_1799910

The liquid filled Yellowjacket gauges I bought are class 1 gauges, so 1% across the entire range.

I think they were close to $80 each for the lowside and highside gauges not including a manifold or anything.

But that's not necessary for a steam boiler. Any cheap 3-2-3 gauge is fine, it would just be nice to have an added low pressure gauge in addition to the required 30 psi gauge.