Jumpy Need on Low Pressure Gauge

FJL

I have noticed that the needle jumps a lot when it is reading the pressure in the boiler, and not just at the beginning of a cycle, but seemingly throughout the cycle. Is this supposed to be what happens? If not, does the gauge need to be replaced? Or could it be something else is causing it to jump?



Recently, a new wet return pipe was installed and there is cleanser in the boiler right now. The entire system will be flushed on Saturday.



Thanks.

MotownSteamer

we seem to be having the same issues

If you've seen my recent threads I rebuilt my instrument manifold, putting the controllers and gauge(s) even higher. My new 0-3 psi gauge arrives today, and I'll finish the build and let you know the results. It occurs to me (after another wallie pointed it out!) that holding vacuum is desirable in a vapor system.



You might want to pipe the gauges even higher, and if that doesn't work [we need to] consider snubbers.

FJL

Snubbers

What are snubbers?

MikeyB

Snubbers

Check out www.gaugestore.com for snubbers, i cannot attach the link

BobC

Wait for water to be clean

My boiler is set to cutout at 12 oz's and back in at 4oz's. The boiler is oversized and it cycles on and off several times before the tstat is satisfied.



The 0-3psi gauge is steady as a rock as it climbs to 0.75 psi and then down to 0.25 psi. It is mounted so it's about 5-6" above the water line in the boiler - I intend to get it up another 4" come spring just to be prudent. The water is my sight glass is clean and bounces about 1/4".



Once they flush out the cleaner on your boiler that gauge glass should be clear and you should not see a lot of bouncing. If not the boiler will have to be skimmed.



Bob

ChrisJ

Dirty

I agree with dirty water.



The few times I had to skim my boiler after installing it even though the water line in the gauge glass wasn't moving a whole lot the boiler was shaking more than normal AND my 3PSI gauge's needle was jumping.  After skimming every time the gauge calmed down.



Not only did the needle become dead steady my overall pressure has dropped a lot since skimming.  No idea why on that one though.

Jamie Hall

Snubbers

won't cure dirty water -- but even with clean water a sensitive gauge (or vapourstat!) may well be jumpy, but that doesn't mean there's something wrong.  It's the nature of the beast.  And snubbers will help that a lot -- particularly making the vapourstat more reliable at very low pressures.

FJL

Snubbers

I am having a hard time finding "snubbers" on the website link above. 



**** Never mind.  I found them.  ****

I have snubbers on my instruments -- the P-trol and v-stat -- but not the gauge.

ChrisJ

Snubbers

Please keep in mind on one of our other pressure gauge issues threads it was mentioned that common snubbers may keep water from draining back out.  It was mentioned as a speculation, nothing definite.



the WIKA 3PSI gauge does NOT like water,  I can personally attest to this.  I would also say you should have that gauge a few inches above the elbow below it to keep water further from it.