Nordyne 664087R Restrictor Orifice 318973-401 Constant Differential Performance: Ensures stable

Constant Differential Performance: Ensures stable cycling with a fixed 6°F differential

Optimized Airflow: The 770RPM speed rating preserves the system's external static pressure balance and heat exchange efficiency

automatic reset switches for precise burner and pump sequencing

Built with two SPDT relays (Single Pole Double Throw)

and TST20037

Nordyne 664087R Restrictor Orifice 318973-401 Constant Differential Performance: Ensures stableThe Nordyne 664087R Restrictor Orifice is a critical fixed bore metering device engineered for precise refrigerant expansion in HVAC evaporator coils. With an exact inner diameter of . 087 inches (Size #87), this OEM Nordyne part is designed to replace worn or fouled orifices that cause irregular superheat or subcooling readings. Proper sizing of the flow restrictor orifice is essential for maintaining the pressure drop required for efficient phase