Control valve balanced 2-way DN 25-65mm - Nodular Cast Iron | Clorius Controls

Clorius G1FB – Balanced 2-Way Control Valve DN25–DN65

The Clorius G1FB is a flanged, single-seated control valve made from spheroidal graphite iron EN-GJS-400-15, rated at PN25. It is designed for hot water, steam, and thermal oil applications where differential pressure requires reduced actuator closing force without the increased leakage of a double-seated valve.

Construction and Sealing

• DN25, DN32, DN40, DN50, DN65.
• Flanges EN 1092-2 PN25; DIN and ANSI options available on product page.
• Actuator connection: G1B per ISO 228.
• Shaft, seat, cone, and bellows: stainless steel.
• Gaskets: Reinz-AFM34 metal and copper.
• Seat leakage: ≤0.05% of Kvs per VDI/VDE 2174.
• Flow characteristic: quadratic, with Kvs/Kvr >25.

Kvs and Stroke

• DN25: Kvs 7.5 m³/h, stroke 7 mm.
• DN32: Kvs 12.5 m³/h, stroke 8 mm.
• DN40: Kvs 20 m³/h, stroke 9 mm.
• DN50: Kvs 30 m³/h, stroke 10 mm.
• DN65: Kvs 50 m³/h, stroke 13 mm.

Operation

Pressure balancing is achieved via a bellows on the shaft, reducing the force required for closing. Without an actuator, the valve remains open via a spring; it closes with pressure on the shaft. Compatible with thermostats, pneumatic, or electric actuators. In temperature increase, the standard setup closes the valve; cooling requires a reverse-acting actuator.

Applications

Used in heat exchangers, district heating, central heating systems, thermal oils, steam processes, and marine installations. Final selection depends on Kvs, Δp, temperature, PN25, medium, and acceptable seat leakage.

FAQ

When to choose G1FB over G1F?
When Δp requires balancing for safe closure with available actuator.

Is it an isolation valve?
No. It is a control valve with defined but not zero leakage.

What about temperatures above 170°C?
For thermostats, a cooling unit is required, while for electric actuators, a high-temperature adapter is necessary.