In-line pressure or vacuum relief valve - F 61 N | KITO Armaturen

KITO F61N Pressure or Vacuum Line Valve

The KITO VD/Sc, F61N series, is a self-actuated in-line valve for venting or breathing of vessels, primarily when installation is within piping systems. Depending on installation orientation, it operates either as a pressure relief valve or as a vacuum relief valve; it is not a combined dual-function valve at a single operating point. It can also be used as a check or overflow device in process lines.

Size and Setpoint Range

• DN 25: PN 40
• DN 50–150: PN 16
• DN 200: PN 10
• ASME equivalents: 1" to 8"
• Setpoint range approx. 1.7 to 200 mbar, depending on DN and load configuration
• For higher setpoints, use type VD/Sc-1, F61.1N series
• C and H1 dimensions can be adapted to existing piping layouts

Materials and Sealing

Body and cover are carbon steel, with optional stainless steel 1.4571. Seat and spindle are stainless steel 1.4571. Standard gasket is HD 3822, with PTFE optional. Standard valve seal is NBR; Viton, PTFE, EPDM, or metal sealing available. For setpoints ≥100 mbar, only PTFE or metal sealing is permitted.

Connections and Flow Calculation

Standard flanged connection is EN 1092-1 type B1. ASME B16.5 Class 150 RF available on request. Flow rates refer to air at 1.29 kg/m³, 273 K, with 40% accumulation above setpoint, per DIN 4119. For lower permissible overpressure, flow must be recalculated.

Typical Applications

• Tank breathing lines
• Protection of vessels against overpressure or vacuum
• Gas, vapor, and vent piping
• Check function in low-pressure networks
• Overflow or balancing in closed systems

FAQ

How does it differ from F30N?
Same operating principle as KITO VD/TA of F30N, but with different VD/Sc construction geometry.

CE marking?
Technical datasheet states version without EC certificate and without CE marking.