In-line pressure and vacuum relief valve - F 37 N | KITO Armaturen | Philippopoulos s.a.
In-line pressure and vacuum relief valve - F 37 N | KITO Armaturen | Philippopoulos s.a.

In-line pressure and vacuum relief valve - F 37 N | KITO Armaturen

Pressure and Vacuum Line Valve KITO F37N

The KITO VD/T3, F37N series, is a self-actuated breather valve designed for fixed-roof tanks and vessels. It features a lateral connection to the tank, a bottom flanged connection for inert gas supply or venting, and a top flanged connection for breathing line. The bottom valve can be used for automatic inert gas (e.g., nitrogen) supply control.

Process Operation

Under overpressure, the valve vents the gas phase to a vent or vapor recovery line. Under vacuum, it allows replenishment via a separate breathing line. For flammable liquids, installation of an explosion-proof flame arrester (e.g., KITO EFA-Det) between tank and valve is required per technical documentation.

Sizes and Settings

  • DN 25–40: PN 40
  • DN 50–150: PN 16
  • ASME equivalents: 1" to 6"
  • Vacuum setting: approx. 1.7 to 148 mbar
  • Pressure setting: approx. 1.7 to 200 mbar, depending on DN and configuration
  • For higher settings, use type F37.1N
  • Face-to-face length C can be adapted to installation

Materials and Sealing

Body and cover in carbon steel or optional stainless steel 1.4571. Seat, spindle, and weights in stainless steel 1.4571. Standard seal is NBR; Viton, PTFE, EPDM, or metal sealing available. For settings ≥100 mbar, only PTFE or metal seal is used.

Connections and Flow Calculation

Standard flange: EN 1092-1 type A. Optional: ASME B16.5 Class 150 RF. Flow rates based on air at ρ=1.29 kg/m³, 273 K, with 40% accumulation above setpoint, per DIN 4119.

Typical Applications

  • Nitrogen blanketed storage tanks
  • Storage of solvents, fuels, or volatile chemicals
  • Vapor lines to VRU, scrubber, or flare
  • Overpressure protection during filling
  • Gas replenishment during tank emptying

FAQ

How does it differ from F33N?
The F37N provides a separate top breathing connection and allows inert gas supply control via the bottom valve.

CE Marking?
Technical documentation states the product is supplied without EC certificate and without CE marking.

Standard (Options)
  • DIN
Connection (Options)
  • Flanged
Material (Options)
  • 1.4571
  • Steel
Pressure Rating (Options)
  • PN 16
  • PN 40

Datasheet and documents

Description

KITO® VD/T3-…

  • As inline armature with venting and breathing function for application on fixed roof tanks and vessels.
  • Equipped with a lateral Connection for the tank connecting pipe, a lower flange connection for a venting conduit and an upper flange connection for a breather conduit.
  • The lower valve can be used to automatically control a supply of inert gas (e. g. nitrogen).
  • For flammable liquids, a detonation flame arrester, e.g. KITO® EFA-Det-… should be provided between the tank and the KITO® VD/T3-…