These directional control valves are basically family with common characteristics and benefits.
- They are seated poppet or ball design for virtually zero leakage at high pressures with low viscosity fluids. They are not “bubble-tight’’ on gas. Note: Normally open models will generally hold a tighter seal on low viscosity liquid or gas because seating force does not depend on inlet pressure.
- They are directly air-actuated for ideal system compatibility in wet or hazardous areas, or when used in air driven pumps or boosters. Yet, if electronic or electrical control is preferred, they can be actuated with any of the wide selection of sub-miniature 3-way solenoid air valves available from many manufacturers.
- They employ the same basic area ratio principle used in Haskel pumps enabling high forces to be easily and directly controlled from low pressure plant main or instrument air.
- Although not normally considered for pressure control, all of the normally open 2-way models can do double-duty in a circuit by also providing a safety relief function simply by installing a small air regulator in their pilot line.