The 23289374 thermal valve plug is used in conjunction with the thermal valve and spring to secure the thermostatic valve into the separator block / airend assembly. This was most commonly used on the UP6-40 and UP6-50 rotary screw air compressors manufactured by Ingersoll Rand.
Typically this valve was paired with the 22186720 thermal valve actuator and the 22186696 thermal spring.
Part #: 47695566001
Part #: 24546558
Part #: 22186696
Part #: 22463368
Part #: 22362198
Part #: 22832885
Part #: 22872857