isolate the vaporstat?

moneypitfeeder

Now that I've finally been able to shut the heat down for a few days here, I'm looking to tackle installing a vaporstat,& low pressure gauge to my boiler. I only have one open tapping to the boiler, (1/4"), and plan to stub out with a 3" nipple from the boiler to a tee, left side 90's to a pigtail, tee, vaporstat on top, and low pressure gauge to the side...right side same only with the ptrol and req'd 30 psi gauge. Wire the 2 in series so that the vstat is the main control, but the ptrol can be my safety. My question is can or should I put a valve in before the pig to the vstat and low press gauge to be able to isolate them to raise the pressure to do a complete blowdown of the boiler. So far I've got almost all the fitting for this in brass, except for a few which my local stores did not have a supply of, or were very poorly machined. Thanks for any and all advice.

BobC

Use the shutoff and add a union.

i would put a shutoff in line with the vaporstat low pressure gauge side of your setup so you can isolate them. I would also put a union in line with the whole setup so you can easily remove the "tree" to clean out the pigtail without having to unwire everything. You may have to rig up a bracket of some sort to stabilize that tree on top of a union.



This is a good source for brass fittings -

  http://www.rittenhouse.ca/asp/Product.asp?PG=323



Bob

crash2009

yes, no, yes, yes, no

Stub out with a 3" nipple, then a cross with a plug.  In the future when you want to clean the tapping just pull the plug, and you don't have to disassemble anything.  You might want to use T's with plugs instead of elbows (where possible) for the same reasons.

Opinions are divided on the subject of isolating a safety control.  Convienience encourages more frequent maintenence, although Murphys Law sides with safety.

moneypitfeeder

a little late

I was already at a different supply house getting fittings, so a tee it is, I do have an iso valve in just on the vaporstat side, the ptrol side will not have a valve since it is acting as the safety override. When (or if) I ever get this finished I'll post a pic of it, just to make sure I haven't commited a major safety/performance faux pas. Thanks, Dee

moneypitfeeder

all working

It's in and wired up, everything seems to be working fine, my system seems to have a hard time getting above .05 psi, so it might be that I won't be able to really dial in the vstat till winter. I started early this morning with all the windows open, but it still wasn't that cool out. So its hard to keep it running long enough to see what it needs. Even at .05 all of my rads up 3 floors were getting hot all the way across. I'll post a pic, but please keep in mind I will be adding a bracket to the top to help support the weight as well as to help persuade the pitch of the nipple to the gauges to flow back to the pigtail. (right now the pig twist is making them spread out and lean the wrong way). Last night I tested with 8 oz. main and 6 diff, and today I set at 6 oz main, 4 diff, but still until I can have it run long enough to build anything its hard to tell where it needs to be set at. BTW in case anyone's curious I have the Marsh Vapor syst. piping in my house.

MotownSteamer

any vacuum problems?

Hi-does your system pull a vacuum at the end of a cycle? If so, is it ragging those gauges? Pulling the needles left past zero?

Jamie Hall

Nice looking installation!

The only thing you might want to watch as you get down to the very low pressures (you're looking at the same pressures I run at) is that you just might want to invest in a snubber just below the vapourstat.  They aren't that expensive, and they're easy to install.  I forget where I got mine.  What they do is smooth out small "jitters" in the pressure the 'stat is sensing.  I needed it.  You may not.

moneypitfeeder

snubbers

I actually have a snubber sitting in my toolbox. I had it on, but it seemed to "snub" too much. I wasn't getting any reading out of the wika gauge with it on. I dunno, maybe it was operator error. But I don't think I tried it under the vstat. maybe I'll give that a try. It does get the jitters sometimes. Thanks!

moneypitfeeder

nope,

This system doesn't pull a vacuum. I will remain forever jealous of those who can make steam below 212*

ChrisJ

water

I know you don't want to hear this but I would move your 3 PSI gauge up higher to keep the bottom out of water which can collect in the tee below it.



I had to do this with mine to keep water out of it, it would end up indicating a slight vacuum and then never move.  Now I can see around an ounce of pressure during a 3 degree recovery in the morning, before it wouldn't indicate anything.  I would work for a while then usually return to the same problem.



I bought all of my fittings for this at Lowes (ugh).  I'm thinking, the Ward cast iron fittings help balance that back out in the end