What does WOG Stand for?

WOG stands for Water Oil Gas and is used to indicate the pressure rating of valves and fittings....

WOG” - General “Non-Shock” pressure rating indicating maximum P.S.I. for  the medias Water, Oil or Gaseous.  It has traditionally been used as a catch all for ambient temperature fluids, simply defined as water, oil or gas.

“W” The definition of  WATER is clear – H²O. 

The terms oil and gas are less clear, and are the cause of major confusion! 

“O” We think of OIL as a hydrocarbon (a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon). The majority of hydrocarbons found naturally occur in crude oil, where decomposed organic matter provides an abundance of carbon and hydrogen. However, oils are also made from animal fats and vegetables.  In valve selection, oil is a liquid that is thicker than water, has lubricating characteristics and flows freely. 

“G” GAS is meant as a vaporized liquid. Gas then can be air, hydrogen, nitrogen, oxygen, etc. 

The real meaning of WOG remains “ambient temperature fluids”.


WOG does NOT cover combustible gases.  Valves for natural gas and liquid propane for example must have the required gas approvals from CSA – always make sure to verify, and follow the installation codes for your area! W.O.G. Rating Does not cover FLAMABLE Gases Natural Gas (NP) or Liquid Propane(LP)