Field glossary

Valve authority

Ratio of the valve's pressure drop to the controlled branch drop; aim high, commonly 0.3 to 0.5 or better

Used across 3 Anvilfield field guides, most in HVAC.

Also defined as

The share of loop pressure drop the control valve takes when open; low authority makes the valve hunt
Control valve pressure drop divided by total circuit drop; low authority causes hunting

Where this shows up