Parallel Pressuretrols

Mad Dog_2

But contrary to what some believe, Vaporstats are NOT for every steam system, but ones that can operate at very low pressures and always on Vapor systems. When misapplied they can be beat to ---- in short order Mad Dog

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David Russell

Parallel Pressuretols

I am looking at my steam heating system and see multiple pressuretrols installed side by side on the same pipe.

Why would this be done?

The Wire Nut

One is probably the "operating" control, used to control the boiler's running pressure (probably should be a VaporStat instead?) and the other is a safety control, set to the upper safe limit to shut the boiler off is the pressure gets that high.... presuming the operating control fails....

Alex

Ed N.Y.C.

P Controls

Boyh controls should NOT be on same line. If line plugs both controls are useless, separate them. ED N.Y.C.

Ed N.Y.C.

P Controls

Both controls should NOT be on same pipe. If line plugs both controls are USELESS. Separate them ED N.Y.C.

wsdave

Interesting point

Interesting point you make Mad Dog which has me thinking.....how would one know if he made a "mistake" purchasing a vaporstat to install on his system?

Just curious before I take the plunge!!!

Dave

The Wire Nut

This is one way

to plumb the 2 controls. Note that each control and the gauge have their own "pigtail". Note, too, the orientation of the pigtails.

Because the 'trols position, the pigtails must be placed so that their expansion movement does not affect the horizontal level of the 'trols.

In the second picture, note that the pigtails can throw the 'trols out of level and they have to be adjusted (always fun with a steel pigtail) to assure that the controls are dead level... This photo was before I leveled them out...

As for when to use a Vapor over a Pressuretrol, I believe that most 1 pipe systems can use them, but I'd best leave that to the experts here...

Alex

Mad Dog_2

This is America.....................................

You can do whatever you'd like. Yes, Ed is 100% correct even though we see that mistake made often. Alex, yes you are correct with the pigtail, but that is becoming less important as Honeywell doen't seem to be making any mercury p-trols or vaporstats, trying to faze them out. Vaporstats are quite a bit more expensive and in many cases a standard Honeywell Merc. p-trol will work very well. I have found out the hard way, that a Vaporstat is VERY sensitive, and if the boiler is bot very clean and maintained, they will be destroyed in short order. They are the vaportats that have a range of 1-4 psi and the ones that are 0-16 ounces. Unless I have a rehabbed vapor system or a system and boiler is almost perfectly size a vaopr stat will cause even greater short cycling. I believe they are the olive in Beefeater Martini.....cherry on the sundae. Mad Dog

wsdave

Vaporstat

Thank you Mad Dog for your comments.

I'm already getting about a 30% savings in my gas usage just by the repiping of the near boiler piping and adding vents to the mains.

I'm not convinced that a vaporstat will add to any savings that I'm now realizing. In fact it may make matters worse, as you stated, because I know my boiler is still slightly oversized even though I reinstalled removed radiation.


I've looked at your posted installation pics and know that you speak from experience. Your work is like viewing fine art!

I will leave the vaporstat on the shelf.

Thanks again,

Dave

William Faust

just by the repiping of the near boiler piping

You are referring (mainly) to a header?

William Faust

Both controls should NOT be on same pipe

WM's LGB-6 gas/steam boiler manual instructs the installer to mount BOTH pressure controls on a horizonal manifold that is mounted atop (and in a line with) the primary LWCO's upper boiler tapping. HO here.

Unknown

It all depends

on what size pipe you use for the pressuretrol manifold .

I have no problems mounting multiple pressuretrols off a single 3/4 inch port . Even 1/2 inch is fine for smaller residential steamers . I think the Peerlees commercial steamer instructions show their setup on one 1/2 inch port .

But one 1/4 inch tee setup for 2 P-trols would be a bad idea .

wsdave

Yes Sir!

Yes William,

All I did was repipe the boiler IAW Utica's specifications and insured the mains were properly vented with Steamhead's help.

See attached photos

Dave

wsdave

Yes

Yes William,

All I did was correct the near boiler piping, add a header and make sure the mains were vented properly with Steamhead's help.

The "old" system only used one tapping (piped in copper) and was bullheaded entering the mains.
Because of the one tapping used it was putting saturated steam into the system knocking down its efficiency.
Along with Dan's books I was able to balance the system between the three floors by properly venting the radiators.
I also added the radiators back into the system that were removed from the second floor bath and third floor bedroom by the previous owner.

You can see in the attached pics.

Dave

William Faust

nice pics

Yeah, Steamhead is the greatest. He is in the zone.

wsdave

Finished Project

ALL the PROs here are GREAT!

Just too many to thank!!

Forgot the finished photo.

Dave

David Russell

Thanks to everyone for the replys. I have some checking to do.

BTW my background is in computer networking, I got Dan's book to try to understand our church's system so we can more intelligently pour money into it to keep it working and hopefully reduce our costs.

The water level in the system has been a problem for a while and most of the recent work has been to address that.

I am attaching some photos of the system and our THREE pressuretrols plus pressure gauge.

Ken_40

Ed is speaking of

a code requirement for large boilers. In the practical world of residential, the tappings may not be present to be able to have two separate tappings for two pressuretrols. Most don't.

The word parallel is incorrect. Probably just semantics. These devises are almost always (wired) in series, not parallel. The are part of the so-called "control circuit" which is nothing more than a string of safeties wired in series so if any one is "set," the entire power source is denied access to the burner.

Ken_40

Serious problem!

The three PT's (pressuretrols) are a good thing. They should be as follows:

1) set lowest, would be the "operating" PT
2) set next higher, would be the "backup operating" PT
3) set the highest, would be the MR (manual reset) PT

The photo suggests the PT's are set too high and that is supported by the gage showing 4# (# = p.s.i.= pounds)!

No heating steam system should run at over 2# tops! By doing so, you: waste lots of fuel, have banging and clanging, destroy the steam main air vents, have water spitting out those vents, fake out any auromatic feeder that may be in place, have uneven and problematic radiation balance problems, etc.

The operating PT should be set to turn off the flame at a scant 2-pounds. Back on at 1/2-pound. The backup operating PT should be set 1/2# higher on the "turn-off setting only, same "back-on". The MR PT 1# higher still. If it is "triggered," it will not allow the burner to ever turn back on, so there is no "back-on" setting. It must be manually reset and: THE REASON FOR ITS TRIGGERING FOUND AND FIXED IMMEDIATELY!

The Wire Nut

From another computer guy...

Ken is electrically correct, but I would posit that the 'trols are plumbed in parallel, hence the terminology, especially since most heating folks are plumbers or PAH.

And I always wondered why the operating 'trol is not wired in series with the T-stat especially on burners with pre and post-purge, like the Beckett AFG.... Certainly the 'trol that's the "safety" should kill the power, but I'd think the operating control, is, in effect, more like a thermostat...

JMHO...

Alex

The Wire Nut

Little piggies...

And they seem to be missing "pig-tails", unless I'm missing something... Without them, say bye-bye to all three of those nice 'trols...

Alex...

Ed N.Y.C.

P Controls

With 3 P controls and a burner that is capable of lo-hi-lo operation . I would tend to think p controls are as follows. #1 operating #2 manual reset #3 Hi fire cut in and out. Just my thoughts ED N.Y.C.

Ken_40

You are of course

correct!

IF, the burner is indeed a step-mod: L-H-L one. And, upon closer examination of the photo, there DOES appear to be a bypass fuel-line fitted to the oil pump!

Good call Ed!

That would make lots of sense for the third PT. I'll bet you lunch it is not working (;-o)