ASCO Solenoid Valve Selection and Sizing

Proper selection and sizing of your solenoid valve will ensure better performance and longer service life.  When choosing a valve, consider the following, or use our application guide form:

Media:  Fluid Passing Through the Valve

  • Be specific – what is the concentration of the fluid?
  • Specific Gravity
  • Viscosity
  • What materials are compatible with the fluid?  Fluid Resistance Guide



  • What is the operating temperature range of the fluid?
  • What is the ambient temperature range surrounding the valve?


  • What is the operating pressure range the valve needs to handle?
  • What is the maximum pressure that the valve could see?
  • Do you need a valve for zero minimum differential pressure*?


  • How much flow does the valve need to pass?
  • Minimum/Normal/Maximum flow rate?
  • Minimum/Maximum pressure differential across the valve?

Sizing:  Will the valve be able to pass the required flow?

  • Improper valve sizing results in below standard performance and usually involves unnecessary cost
  • ASCO Valve Sizing

Need assistance in Valve Sizing?  Contact us now!

ASCO Engineering Guide (PDF)

*  Direct acting valves operate by the solenoid core directly opening or closing against the orifice in the valve body, and will operate without any differential pressure across the valve.  Direct acting valves usually have small coils and small valve orifices.  For higher flow rates, pilot operated valves are used.  These have a diaphragm and a bleed orifice that uses the fluid pressure to close off against the valve orifice.  Pilot operated valves typically require 5 PSI differential across the valve in order for the valve to operate.