Safety valves - SAFE P | ARI

ARI-SAFE-P Spring Loaded Safety Valve

The ARI-SAFE-P is a direct spring-loaded safety valve designed for overpressure protection of pressurized equipment in steam, air, and water systems. The series includes types 921, 922, 923, and 924, differentiated by cap design, lift lever configuration, and spring cover arrangement.

Technical Specifications

• Design: Spring loaded, direct acting
• Versions: D / G / F
• Nominal sizes: DN 15–150
• Pressure classes: PN16, PN40
• Body materials: EN-JL1040, EN-JS1049, 1.0619+N, 1.4408 (stainless steel)
• Temperature range: -10°C to +450°C; -60°C to +400°C for 1.4408 stainless steel
• Flanges: DIN EN 1092-1 / EN 1092-2
• Certifications: EN ISO 4126-1, AD2000-A2, TRD 421, VdTÜV 100, TÜV SV 811

Type Differences: 921 / 922 / 923 / 924

• 921: Enclosed manual lift mechanism, closed spring cover
• 922: Open lift lever, closed spring cover
• 923: Gas-tight cap, closed spring cover
• 924: Open lift lever, open spring cover

Selection depends on process medium, temperature, test lift requirements, and whether the mechanism can be exposed to the operating environment.

Media and Applications

Suitable for:

• Saturated or superheated steam
• Compressed air
• Water and thermal circuits
• Pressure vessels, heat exchangers, boilers, air receivers, auxiliary process lines

Sizing requires mass flow, temperature, set pressure, and backpressure. For gases, molecular weight and isentropic exponent are needed; for liquids, density and viscosity are required.

Backpressure and Installation

Accumulated backpressure in the discharge line should generally not exceed 10% of set pressure. For higher backpressure, a balanced bellows option is recommended. Installation requires vertical orientation, clean piping, correct flow direction, condensate drainage, and inlet pressure loss limited to 3%.