Antique pressure gauge

That is a cool gauge! And if it were mine, I would certainly plumb it into my system. I agree about the danger in its twitching - it would be shame to have the needle loosen.

Now, about the structure that the aux tank sits on: I am not a cautious person, at all, but I think that it should have a couple of diagonal braces. Not that I don't trust your welds, it would just be prudent.

Bob

"Ignoramus27433" wrote in message news: snipped-for-privacy@giganews.com...

The glycerin-filled gauge on my log splitter pump jumped its gearing, possibly from vibration as the relief setting isn't much over half scale on it.

Your gauge may have internal threads for a "pressure snubber" screw or you could add one in line.

jsw

Bob, it has some reinforcement braces near the floor, you do not see them on the picture. It is sturdy enough.

I will re-plumb the gauge into the tank directly. It looks like we both agree on that. It was a mistake to plumb it near the output.

Thanks, Jim, you are the third person who shares this concern, I will do one thing or another, add a snubber or hook up somewhere else.

If you plumbed in an orifice followed by a small tank to absorb the remaining impulses you could leave it there . Or for that matter a larger diameter line to the gauge might be enough .

Yes, that's a valid concern. Is there another plugged boss where you could mount it in the tank rather than at the compressor outlet? Many tanks have multiple bosses for running the piping from a different direction. Or insert it above the union on the tank outlet plumbing at the right.

Also, a concern I have is that the large gauge is out in the open and can easily be damaged. Consider putting a shield around it, Ig.

Yet another concern is that the outlet is on the very bottom of the (white upper) tank, ensuring that all moisture in that tank comes out in the air line. Very strange.

I just learned something. Thanks

If that won't work out, you can make a pneumatic low-pass filter. Just put a restriction of some sort (I was thinking of some purpose-made gizmo with a small orifice, but just a valve will do -- crack it barely open and leave it), then a couple of feet of largish-diameter (1"?) pipe, then your gauge.

Fast variations will be lost, but slow variations will register. If you do it with a valve, you can adjust the tracking speed by opening or closing the valve.

(Larry's idea is better, if it works).

Yes, I will look into something, or other.

That is for draining.

Here it is, called a Throttle Screw:

-jsw

I'll bet the rubber hose he used initially helped dampen the bounce.

Good idea, if there's one in the line already.

Yeah, the direct output of the compressor has far too much variance in pressure for a poor gauge to survive.

The same is true in car engines for vacuum gauges. The farther away from the cylinders, the better. Directly under the carb is the best.

I could have sworn I saw a quick disconnect fitting on the end of that line, Ig. Oh, well.

Simply add a restiction between the line and the guage to slow down the response. A needle valve that you can adjust works well, so dose filling a pipe nipple with solder and drilling a very fine hole through it. Since there is virtually no flow, the restriction will have virtually no effect on the pressure but WILL damp out the fluctuation

They make "pulse dampers that are used between a gauge and a pulsating source.

If you didn't notice the references I posted to gauge snubbers, one suggests starting with an 0.020" hole.

Several sizes of these bits have worked well enough for me in brass, better than the #61-80 set from Enco.

I tried one in steel and it didn't dull instantly, FWIW.

-jsw

Is there a check valve between the pump and tank? If so, you are not reading tank pressure. If there is not one, there should be so the pump unloader can work.

it does not need a check valve.

Put in a snubber, everything is great now. Thanks for the advice.

Ignoramus16276 fired this volley in news: snipped-for-privacy@giganews.com:

Yeah... I have no idea what that poster was thinking... it had nothing to do with gauging.

Ig... If you need to plumb the gauge in a pulsing line to make it more accessible or visible, they sell "gauge line snubbers" designed to do exactly what you want -- take the pump pulses out of the stream before they reach the gauge.

Lloyd