Castel – 3030/44C173 – 17.3 bar Safety Relief Valve, ½″ NPT×¾″ G, PS 55 bar

The Castel 3030/44C173 is a fixed-pressure safety relief valve tailored for refrigeration, air conditioning, and HVAC systems. It features a ½″ NPT inlet and ¾″ G outlet, factory-set to open at 17.3 bar with a maximum allowable pressure (PS) of 55 bar—ideal for protecting condensers, piping, and receivers.

Key Features:

• Model / P/N: 3030/44C173 (17.3 bar set pressure)  

• Connections: ½″ NPT threaded inlet × ¾″ G threaded outlet ()

• Set Pressure: 17.3 bar

• Max Allowable Pressure (PS): 55 bar  

• Adjustability Range (3030/44C): 9–50 bar; this unit is fixed at 17.3 bar  

• Body Material: Brass with PTFE-seated, direct spring-loaded mechanism (unbalanced design)  

• Orifice & Flow: 113 mm² orifice, discharge coefficient Kd 0.90  

• Temperature Range: –50 °C to +150 °C  

• Standards & Compliance: Complies with EN 378, PED 2014/68/EC, and ASHRAE A1 refrigerant group