In-line pressure or vacuum relief valve - F 70 N | KITO Armaturen

KITO F70N In-Line Pressure Relief Valve

The KITO DS/oG-PA, F70N series, is an in-line pressure relief valve designed for installation at the end of a tank vent line. The technical datasheet specifies it as a pressure relief valve only, not a combined pressure/vacuum device. It is mounted vertically on the fixed roof of storage tanks, with a side flange directing product vapors to a collection header or atmosphere.

Operation

The valve opens when tank pressure exceeds the setpoint of the pallet. This arrangement limits unacceptable overpressure and reduces vapor losses or fugitive emissions via controlled venting. No electrical or pneumatic actuator is used; actuation is purely mechanical.

Sizes and Setpoints

• DN 50–150: PN 16
• DN 200–300: PN 10
• ASME equivalents: 2" to 12"
• Setpoint range: 2 to 60 mbar
• Flow rates calculated for air, ρ=1.29 kg/m³ at 273 K
• Rated flow at 20% accumulation above setpoint

Materials and Sealing

Standard construction: upper/lower body in cast steel 1.0619. Optional: stainless cast steel 1.4408. Seat: stainless 1.4571; gasket: PTFE. Pallet and spindle selected by pressure range—aluminum for low setpoints, stainless 1.4571 for higher. Sealing: FEP/HD3822 for low setpoints, PTFE for >14 mbar.

Connections and Standards

Standard connection: flanged EN 1092-1 type B1. Optional: ASME B16.5 Class 150 RF. Datasheet notes version without EC certificate and without CE marking.

Typical Applications

• Fixed roof tank venting
• Product vapor routing to collection header
• Minimizing vapor loss during thermal expansion or filling
• Low-pressure vent lines in chemical and petrochemical facilities

FAQ

Is this a vacuum valve?
The F70N datasheet describes a pressure relief valve only. Vacuum protection requires a separate device or different valve type.

When is flow verification required?
When allowable overpressure differs from the calculation basis or when the gas density differs from air.