I have a couple of questions on mounting my primary pressure gauge. It weighs 2.5 lbs and has an OD of just over 5.5". It is 2 and 1/8 " "deep".
1. I assume at this weight that having it supported only by the siphon tube is unwise. Am I correct ?
2. Assuming then that I will have to mount it directly to the boiler, do I need to be concerned about temperature transfer from the face of the boiler to the gauge ? Do I need to put the gauge on stand-offs so that it does not get to hot ?
I couldnt pass it up when I saw it originated in Providence Rhode Island............I am about 20 Minutes sout of there, it seemed right to give it an application close to its roots.
What a beautiful gauge! You are lucky to find it. Now build yourself a dead weight tester to make sure it reads right. They are stone simple and the only things needed for very good accuracy are a micrometer and some way of weighing the weight. How close you are on the weight and ram diameter control the accuracy of the calibration.
Yes, probably a good idea to support it better. I would make a simple bracket that attaches it to the boiler. On locomotives it is usually made from 1/8" strap or something like that. It could be attached to the boiler lagging if that would work. Normal air circulation will keep it from getting too hot.
I have a similar gauge that reads steam pressure to 1000 psi. Since I have no use for it and no one I know owns a destroyer or a nuclear plant, I am making plans to remove the works and hide a bicycle speedometer in the old case for use as an engine tachometer.
As has been noted elsewhere, if you enter a calibration number of 2682 into most bike speedos, then 1000 rpm reads out as 100 mph. The magic number, by the way, is the circumference of the notional bicycle wheel in millimeters. Self powered and with automatic shut off. Most convenient All that is needed is a magnet stuck to the flywheel somewhere discreetly. Radio Shack sells some little ones that are so powerful that they don't need to be glued on.
With a cheap GPS and a tach, I'll have more information than I will know what to do with.
If you think you are too small to make a difference, try sleeping with a mosquito.
Dalai Lama
I bought the gauge from a guy who works on barometers and other measuring devices. He calibrated it and ensured it is reading correctly at 125 lbs. I am planning on running at 135 or below so that should work out well. I just looked up the "General FIre Extinguisher Co. of PRovidence RI" and it turns out it was started by the guy who invented the automatic sprinkler system, Frederick Grinnell, kind of cool.
I have seen set ups where people are running two pressure gauges. Is there a specifric reason to do so ?
I've not felt the need for two gauges reading at the same point.
There are all sorts of other places besides the boiler that are worthwhile or at least interesting. Feed water pump output. After the throttle as near as is convenient to the engine. Condenser output vacuum. Sometimes a good idea to use a compound gauge there as the pressure can go positive. Between stages on a compound; receiver pressure can be illuminating.
I'm torn between wanting lots of stuff hanging allover the power plant and a, perhaps conflicting, desire to make it easy for visitors to want to and be able to run the boat.
One look at Wes's power plant will give a newby the vapors complete but something more like the African Queen is also likely to alarm a potential member of the black gang.
If you think you are too small to make a difference, try sleeping with a mosquito.
Dalai Lama
I was considering putting a smaller gauge close to the engine to see what kind of pressure I have at the throttle and to have a back up for my 1920 primary..............of course my other gauge is a 1906........ ........
How about the affect of heat on pressure gauges ? I could tap my boiler housing and mount the big gauge right to the boiler, it would be the most "static" way to mount it, it would get warm hwever, and also means I have to drill three holes in my nice smooth boiler housing................. I could still do that and put in brass spacers if heat is an issue, or I could make some sort of bracket.
My only concern about the bracket route is that it will look like I made it......................
Can someone offer an opinion on the temperature question ? If you flushmount a gauge tot he boiler housing is its accuracy affected ?
If it is, what have people done to mitigate the effect.
jon
P.S. - If I want to mount a remote gauge, can I get away with 1/4 " or 3/8" copper tubing ? I would put a shut off close to the boiler as well as having a shutoff at the gauge before the siphon loop.
You can definitely use 1/4" copper line to hook up your gage; this is done all the time and it's how I did Otter's gage as well.
Don't let the gage get hot; warm is ok. If you can hold your hand on it, it's fine. A bit of an air gap between the gage and the mounting surface should take care of things.
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