Low pressure regulator

[dwarren48]

Hi, would someone be able to recommend a regulator for a testing manometer I'm putting together. Supply is 18"Hg, I'd like to be able to regulate the pressure fairly accurately in the range 0 to 5"Hg.
Thanks, Don

[86rocco]

You might be over thinking things. If all you're doing is testing a manometer, that doesn't require any flow so instead of using an 18"Hg supply with an adjustable regulator, why not just use a simple static water column to supply the test pressure? The density of Hg is 13.534 so, every 13.534"WC is equivalent to 1"Hg. You can get a highly accurate test pressure simply by adjusting the height of the water column.

[dwarren48]

I’m actually using this setup on a Sun distributor machine. The Ford Load o matic distributor from the mid 50’s use a Venturi vacuum signal which ranges from 0-3”Hg. The machine itself has a vacuum pump producing around 18”Hg. It has a very crude regulator in the line which bleeds air into the line to reduce the pressure. I’ve coupled in a 36” H2O manometer to get an accurate reading of the supply to the distributor. My concern is being able to fine tune the vacuum signal to the manometer as each distributor has 4 test points based on different RPMs.