On Wed, 30 Oct 1996 ERogers470@aol.com wrote: > main problem is the primary pump. I get out only 10 inch of mercury, while > the manual states it should be 50 inches. Could someone give me an idea > where my problem is? To remove the pump is very extensive, so I would like > advice before I undertake that project again!!! Eugene, Could it be that your pump is fine, and that you might have used the wrong units? Remember that one standard atmosphere is approx. 760mm Hg (Mercury), or approx. 29.9 inches Hg, which is approx. 32 feet Water, and approx. 15 psi(pounds per square inch), 384inches water pressure. If your manual is referring to 50 inches of water, which many pneumatic musical instruments might run their pumps, then your observed reading of 10 inches Hg would be about 5psi. or 128 inches water, which would meet or exceed the required 50 inches of water listed in the manual. Freshly rebuilt pneumatic pumps will often greatly exceed the listed required "blanked-off" pressure. If this is so, then you might not have pump problems at all; merely a calculation to reconsider. Try remeasuring the pump output using a different gauge to insure that your readings are correct. Fred Scoles, RPT
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