Pressure and vacuum relief valve - E 21 N | KITO Armaturen

KITO E 21 N – Pressure/Vacuum Valve VD/oG

The KITO VD/oG-… is a terminal breather valve designed for tank vent openings. It is primarily used on fixed-roof storage tanks to limit non-permissible overpressure and vacuum, and to reduce gas volume losses or non-acceptable emissions. Installation is vertical on the tank roof.

Sizes and Settings

• DN 50, 80, 100, 150: PN 16
• DN 200, 250, 300: PN 10
• Alternative sizes: ASME 2" to 12"
• Vacuum setting: 2–60 mbar
• Pressure setting: 2–60 mbar
• Flanges: EN 1092-1 Type B1, optional ASME B16.5 Class 150 RF

Construction Materials

Standard body: cast steel 1.0619. Optional: stainless cast steel 1.4408 or aluminium (DN 100–300). Cover: carbon steel, optional stainless 1.4301 or aluminium. Seat: stainless 1.4571. Main gasket: PTFE. Protective screen: stainless 1.4301.

Pallete and Sealing Options

Pallete material depends on setpoint range. For 2 to <3.5 mbar: aluminium pallete. For ≥3.5 to 60 mbar: pallete and shaft in stainless 1.4571. Sealing: FEP & HD3822 for low range, PTFE for settings above 14 mbar.

Flow Calculation

Flow curves are based on air density 1.29 kg/m³ at 273 K. Rated flows are achieved at 20% accumulation above setpoint. For lower permissible overpressure, recalculate flow accordingly.

Certification Note

The type sheet states E 21 N is supplied without EC certificate and without CE marking. It must not be considered a certified explosion protection device for flammable vapors without separate technical assessment.