The KITO VS/KS-1-…-IIB3, type D11.1N, is a self-actuated vacuum relief valve designed for air intake ports on tanks, vessels, and pipelines. The valve opens at a preset differential pressure when vacuum exceeds the setpoint, preventing unacceptable negative pressure in process equipment. Integrated flame arrester element is suitable for flammable liquids of explosion group IIB3, MESG ≥ 0.65 mm, up to 60 °C.
Typical uses include:
D11.1N 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 connection available.
This version is intended for higher vacuum setpoints than D11N. Minimum settings: above 200 mbar for DN 50–100, above 150 mbar for DN 125–150, above 100 mbar for DN 200. Maximum typical setpoint: 350 mbar. For lower setpoints, use D11N series.
Standard construction: carbon steel body and cover, optional stainless steel 1.4571. Seat, spindle, spring components, and flame arrester element are stainless steel. Valve sealing is metal-to-metal; flange gasket is HD 3822 or optional PTFE.
Type examination certificate per EN ISO 16852. CE marking in accordance with ATEX Directive 2014/34/EU.
Is an actuator required?
No. Operation is mechanical via spring and differential pressure.
When to select D11.1N over D11N?
When the tank design allows higher vacuum and a higher opening setpoint is required.
What is checked during maintenance?
Cleanliness of flame arrester element, seat, valve disc, seals, and free movement of the mechanism.
KITO® VS/KS-1-…-IIB3
