Mueller Industries A17939 Check Valve L99H008 If the millivolt output drops

If the millivolt output drops below the required threshold

including high-pressure R-410A and POE/PAG oils

Proper installation involves ensuring the bleeder resistor (if applicable) is intact to prevent arcing and ensuring the terminal connections are secure to avoid high-resistance heat build-up

eliminating the need for field modifications or line-set adjustments

This 120Vac solenoid features a 1/4" NPT connection and a robust brass body

Mueller Industries A17939 Check Valve L99H008 If the millivolt output dropsThe Mueller Industries A17939 is a high performance 7 8" Magnetic Check Valve designed for critical backflow prevention in commercial refrigeration and air conditioning systems. Engineered with a hermetically formed solid copper body, this valve eliminates potential leak paths, ensuring system integrity under high pressure conditions up to 800 PSI (55 bar). The internal magnetic mechanism provides a positive seal with a minimum pressure differential