Control valve STEVI Smart - 440/441 | ARI

ARI STEVI Smart 440/441 – Analog Control Valve

The ARI STEVI 440/441 is a straight-through control valve designed for continuous regulation of flow, pressure, or temperature in industrial circuits. Available in DN15–DN250, with flanged DIN connections and bodies made from EN-JL1040, EN-JS1049, 1.0619+N, or stainless steel 1.4408, with pressure classes PN16 to PN40.

Application Field

Used in water, steam, hot water, gas, and industrial fluid circuits, provided chemical compatibility of body, seat, and sealing materials is confirmed. Typical applications include heat exchangers, steam networks, HVAC installations, heating/cooling processes, and flow control lines.

Differences Between 440 and 441

• STEVI 440: Version with standard shaft sealing using PTFE, EPDM, or graphite, depending on DN and operating temperature.
• STEVI 441: Version with stainless steel bellows, suitable for reduced external shaft leakage or operation at higher temperatures. Graphite bellows cover up to 450°C.

Control Characteristics and Tightness

The valve is available with parabolic plug or V-port, equal percentage or linear flow characteristic. Standard seat tightness is class IV per DIN EN 60534-4, with options for tight closure IV-S1 and soft seat PTFE up to class VI, where temperature and differential pressure allow.

Actuation and Automation

Can be combined with ARI-DP pneumatic actuator, max air pressure 6 bar, or with ARI-PREMIO and AUMA SAR electric actuators. Options include fail-safe, handwheel, torque/travel switches, and versions for safety systems per DIN EN 14597.

FAQ

When to choose 441 over 440?
When external shaft leakage is critical or operating temperature requires bellows.

When is a soft seat required?
When the process demands lower seat leakage, e.g., class VI, with temperature and Δp control.

What is needed for sizing?
Medium, flow rate, inlet/outlet pressure, temperature, allowable leakage, piping DN, required Kvs, and control signal.