Vacuum relief valve - D 12.1 N | KITO Armaturen

KITO D12.1N Vacuum Relief Valve

The KITO VS/o-1-…, type D12.1N, is a self-actuated vacuum relief valve designed for end-of-line installation on tank vent nozzles. It admits air when the tank vacuum exceeds the setpoint, preventing unacceptable negative pressure in the tank shell. This model is not explosion-proof and is not intended for flammable media.

Applications

Suitable for:

• water tanks, auxiliary liquids, and non-flammable chemicals,
• process vessels with vacuum risk during discharge,
• installations requiring vacuum protection without flame arresters,
• shared nozzle with pressure relief valve for combined pressure/vacuum protection.

Dimensions and Setpoints

D12.1N series covers DN 50 to DN 200. Flanged connections per EN 1092-1 type A: PN 16 for DN 50–150, PN 10 for DN 200. Optional ASME B16.5 Class 150 RF available. Maximum standard setpoint is 350 mbar. Minimum setpoints: >200 mbar (DN 50–100), >150 mbar (DN 125–150), >100 mbar (DN 200). For lower setpoints, use D12N series.

Materials and Sealing

Standard construction: carbon steel body/cover, optional stainless steel 1.4571. Seat, spindle, and spring components are stainless steel. Valve seat is metal-to-metal. Flange gasket is HD 3822 or optionally PTFE.

Sizing Criteria

Sizing is based on allowable tank vacuum, required air inflow, gas density, and vent line losses. Flow curves are for air at ρ = 1.29 kg/m³ with 40% accumulation above setpoint, per DIN 4119.

FAQ

Is an actuator required?
No. Operation is mechanical via differential pressure and spring.

When to select over D12N?
When higher vacuum setpoints are required.

CE or EC certification?
No. Technical datasheet states no EC certificate and no CE marking.