Bouncing vapor gauge

Abracadabra

Please see youtube video I link to below. Turn down your volume.  It's a big power burner. Is it normal for a gauge to be bouncing this much?  This happened after I significantly increased the venting on the main (as in completely removed the main vent). Prior to the venting increase the gauge would read properly and cycle between 4 and 12 oz. (hi/lo burner).  New gauge.











<a href="http://www.youtube.com/watch?v=Qwm0g3o9qqI">http://www.youtube.com/watch?v=Qwm0g3o9qqI</a>

nicholas bonham-carter

Great video!

The video shows exactly how ineffective the standard gauge is at the lower pressures needed for our systems!

If that was taken during the venting phase, I would say that your main venting is still not adequate. Add main vents until your gauge shows 1 ounce back-pressure, and yes there is bound to be some jumping of the needle at these low pressures. Some people (including myself) have put snubbers on the gauge, but I now have taken mine off, thinking that it's like swimming in your overcoat( snubs too much).--NBC

Abracadabra

can't add more venting...

.. maybe i should add a vacuum pump ;-)

nbc,  I can't add any more venting.  It was a completely open pipe when I was running that.

Rod

Gauge Snubber

Hi- I was going to suggest a gauge snubber



Ray Gauge Snubber

http://www.valvestore.com/products.asp?dept=1122



Porous for Steam - Part # 32627  - 1/4 “  NPT Stainless

                                - Part # 32618  - 1/4 “ NPT Brass



though I see NBC isn't overly enamored with them.so you might want to discuss it more with him.  I used one on a friend's vaporstat which was oscillating a lot.

- Rod

nicholas bonham-carter

Open vent still constipated?

I am amazed that the back-pressure isn't lower with an open pipe. One of the old sales brochures in the archives here had a pitch such as,"nothing can vent the air from the system better than an open pipe", and the vent pipe went up the chimney.

As far as snubbers, don't just follow my remarks as it was a gut feeling.--nbc

Abracadabra

...

*shrug*  It's a large long main. 

Layout attached: 

Jamie Hall

My $.02

on snubbers -- they do damp the swings a lot, and it really depends on what you are trying to do and how the whole thing is set up.  I like to have them on vapourstats, particularly when they are set very low, as they eliminate false trips from small pressure blips -- and what you are trying to do with them is control on the average pressure.  If your cutout is set at, say 6 ounces, and the blips are plus or minus an ounce, a snubber would help a lot.  On the other hand, if you cutour is set at perhaps 16 ounces, they don't make such a difference...

ChrisJ

snubbers

I'm curious if you have since installed a snubber and if so how much did it help?



On another note, whenever I open up a layout and vents are labeled "V1, V2" and so on it confuses me every time.  I work a lot with vacuum tubes and schematics always have tubes labeled in the same way.  It does make me laugh after the few seconds of "duh".

Abracadabra

snubber

nope, no snubber. With the main vents on, the bouncing is decreased quite a bit.