The Diaphragm & Seat Sub-Assembly is a component of breathing circuit gas system used to regulate the pressure in the breathing circuit. The pressure relief valve assembly provides accurate pressuring while ventilating a patient with the use of diaphragm. The amount of pressure buildup in the bellows should be limited and also gases are to be released for scavenging. For adjusting these pressure limits, a diaphragm and seat subassembly are used as a part of pressure relief valve assembly. These are being used in MS CARESCAPE™ Monitor B650, ARC iCentral, MS Dash™ 4000, ARC Aestiva 7100, MS PRN50 Writer, ARC Airway Gas Module, ARC iVent 201, ARC Testing Service, MIC Giraffe™ Warmer, ARC Aestiva 3000, MS CIC Pro, ARC Anesthesia Monitor, MIC Panda™ iRES Warmer, ARC Aespire 7100, MS Solar 8000, ARC Airway Gas Module, ARC iVent 201, ARC Testing Services, MS CO₂ MODULE, ARC Monitor CardioCap 5, MS CIC Pro v5, ARC Aestiva MRI, ARC Engstrom Carestation, ARC Aestiva 7100, ARC Aisys, ARC Monitor, ARC S/5 Monitor FM, ARC Airway Gas Module, ARC S/5 Monitor Anesthesia, ARC ADU, ARC Monitor CardioCap 5, ARC Airway Gas Module, ARC Light Monitor, ARC ADU, ARC MRI Monitor, ARC Aestiva 7100, ARC Aespire 7900, ARC Tec 6 Plus and ARC Aespire View.