Make a manometer (propane pressure gauge)

[austinado16]

Here are the photos of the Manometer I made today to test the working gas pressure at my fridge and then adjust the 2 stage regulator at the propane tank accordingly.

I used some 1/8" thick board that is white on one side.  It was scrap from my recent ceiling restoration.  Following the instructions I found online, it's 6" wide, 24" tall.  The 1/4" I.D. PVC tubing is .75 cents/foot and I bought 6 feet.  It's held to the board by zip-ties.  12" from the top of the board, I marked my "0" position.  Then I marked upward, every 1/2" and labeled them 1-16 (in other words, 8" tall) and these are the "Inches of Water Column" that you're gauging.......because the water is moving down on one side of the tubing and up on the other side, so you don't actually measure a full inch on just one side.

I filled the tube with water which I dyed with "bluing" for laundry.  You can use food coloring too, I just didn't have any.  Simply fill the tubing so the water level parks at your "0" line.

I used a scrap of 2x4 for the base so it would stand up during use.

The fitting on the fridge is 1/8" male pipe thread with a 1/4" barb to match the PVC tubing.

We want to see 10.5"-11" of water column, so I hashed in green, that specific zone on my gauge.

I turned the gas valve off on the fridge pipe, unscrewed the brass plug from the pipe, just after the safety shut-off vavle, and screwed in my new barbed fitting.  Then I pushed on the PVC tubing, turned on the gas valve and depressed the safety button so gas would flow out to my gauge.  I initially had about 12.5" so I turned the adjustment screw on the propane tank regulator counter-clockwise 1/2 a turn at a time until I had 11".  I tested again with the gauge still hooked up, and the fridge burner lit.

So there you go, have fun!

[AustinBoston]

Then I marked upward, every 1/2" and labeled them 1-16 (in other words, 8" tall) and these are the "Inches of Water Column" that you're gauging.......because the water is moving down on one side of the tubing and up on the other side, so you don't actually measure a full inch on just one side.

I started out by just looking at your pictures.  It looked like you were measuring in 1" increments, which would have been wrong.  I was just about to fire off a volley when I decided I'd better read what you wrote.  What a novel idea...

The key thing is the difference between the two water levels, so if one side rises 1/2", the column has risen 1" (because the pressurized side went down by 1/2" and the other sie went up by 1/2" - total change 1").

In any case, your manometer is simple, reliable, and accurate.  Well done.

Austin