Lochinvar & A.O. Smith 100318326 Pressure Switch 320788 704 The heavy duty plated steel frame The heavy duty plated steel frame and laser welded bellows contribute to an extended service life by resisting mechanical fatigue This bracket is designed for heavy duty 150 and 300 lb in spring return and non spring return actuators this component comes with factory calibrated set points designed to match the safety parameters of the NKC series and should not be tampered with in the field Smith 100318326 Pressure Switch is a critical safety component designed for precise water pressure monitoring in high efficiency Noble Fire Combi Boilers and NKC series units