Chapter 3

Let’s Talk About Pressure

Here’s a quick lesson in pressure and vacuum terminology. If you’re going to speak the language of vacuums with those of us in the business, you’ll need to know these common pressure terms.

  • W.G. — Water Gauge (plus a height dimension).
  • W.C. — Water Column or Column of Water.
  • Inches H20 — Inches of Water (Column).
  • S.P. — Static Pressure (usually in inches).
  • W.L. — Water Lift

These are all the same thing. They can reference pressure or vacuum, but they are normally associated with dust collector fan performance. In vacuum systems, the terms are most often used when talking about pressure differential across a filter media.

PSI

Torr

Inches Hg