Control valve STEVI Pro - 470/471 ANSI | ARI

ARI STEVI Pro 470/471 ANSI – Control Valve for Industrial Processes

The ARI STEVI Pro 470/471 ANSI is a linear flow control valve designed for industrial regulation of flow, pressure, or temperature. The series covers DN25–DN200 / NPS 1"–8" with ANSI 150 or ANSI 300 flanges, while butt weld versions are available in DN25–DN150 / NPS 1"–6". Standard bodies are SA216WCB, with an SA351CF8M version available in ANSI300.

470 vs 471

• STEVI 470 ANSI: Features a stem packing design. Available with PTFE V-ring up to 220°C, PTFE packing up to 250°C, or graphite up to 425°C.
• STEVI 471 ANSI: Equipped with a stainless steel bellows and secondary sealing. Chosen when atmospheric leakage must be minimized or when media/temperature conditions do not allow standard packing.

Pressure, Temperature, and Connection

Operating pressures depend on material, class, and temperature. For SA216WCB, the ANSI150 version is rated at 19.6 bar at 38°C, decreasing to 5.5 bar at 425°C. The 470 ANSI300 reaches 51.1 bar at 38°C and 28.8 bar at 425°C. Flanges comply with ANSI B16.5 and face-to-face dimensions with ANSI / ISA S75.08.01-2016.

Trim and Seat Leakage

Available trims include parabolic plug, V-port, soft seal PTFE, hardened edge, pressure-balanced plug, and perforated plug for noise reduction. Standard leakage is Class IV per ANSI / FCI 70-2, while PTFE soft seal can achieve Class VI up to 200°C. Rangeability is 50:1 for DN25–DN150 and 30:1 for DN200 or perforated/V-port trims.

Actuation

Compatible with pneumatic ARI-DP 32–35, max air pressure 6 bar, or electric ARI-PREMIO / PREMIO-Plus and AUMA SAR. Options include spring-opening, spring-closing, manual override, IP65/IP67, and ATEX configurations.

FAQ

When is a perforated plug selected?
For steam or gases with high pressure drop, where noise reduction is required.

When is a pressure-balanced plug selected?
When differential pressure increases actuation force and required thrust must be minimized.

Key selection criteria: media, flow rate, P1/P2, temperature, Cv/Kvs, leakage class, fail-safe position, and actuator type.