Rule of thumb with steam gauges is that normal working pressure should be one-half the gauge's highest pressure. Thus, a 300lb gauge would be just right for a boiler normally running at 150lbs. This also puts the needle at the 12 o'clock position, so one can tell at a glance if pressure is up or down. Note: I said working pressure, good steam person doesn't lift the safeties often, you'd run at 150 lbs with safeties at 155 or 160.
At least that's what I was taught--but then our boats were a lot smaller, my Mikahala was/is 16'. Found it on sale on eBay the other day, at nearly 10x what I bought her for back in '78. I should never have let her go, I guess.
S'
David D.
|