Re: '50 8 Manifold Pressure?

Posted by Fish'n Jim On 2016/9/24 19:42:51

FYI - technically, vacuum is pressure.
We refer to gauge pressure (psig) as above atmospheric. Where as absolute pressure (psia) is measured from full vacuum, P=0 psia.
"Vacuum" is fractional atmospheric pressure = 14.7 psia, 29.92 inches Hg, 0 psig, 33' H2O.
Eg, 5 psia = 20 inches of "vacuum" = 10 inches of Hg = -9.7 psig.
It just depends where measured from, i.e. relative measurement.
We use common terms, "vacuum" & "pressure" to conveniently distinguish above/below atmospheric but it's all pressure.