Full-Bore Knife Gate Valves - FB Series | Wey Valves
Full-Bore Knife Gate Valves - FB Series | Wey Valves

Knife Gate Valves - FB Series | Wey Valves

WEY FB Knife Gate Valve – Full Bore Design

The WEY FB series is a bidirectional isolation valve for pipelines requiring pigging or mechanical cleaning. Its full-bore geometry keeps the internal passage aligned with the nominal pipe diameter, while the gate guides remain outside the flow path. From DN200 upward, brass scrapers remove deposits from the gate during each opening cycle.

Technical Data

  • Nominal sizes: DN50–DN2000

  • Operating pressure: up to 10 bar, depending on DN, actuator and service conditions

  • Flange connections: PN6, PN10, PN16, ASME Class 150, BS10 and AS2129

  • Face-to-face dimension: EN 558 / ISO 5752, Series 20

  • Leakage test: EN 12266-1, Leakage Rate A

  • Body materials: EN-GJS-400-15 ductile iron or stainless steel 1.4408

  • Gate materials: stainless steel 1.4301 or hard chrome-plated 1.4404

  • Standard seat seal: NBR

The transverse seal limits leakage to atmosphere and can be readjusted through lateral compression screws without removing the valve. In the closed position, the gate is mechanically supported to reduce deformation under differential pressure.

Actuator Options

  • Handwheel

  • Bevel gearbox

  • Pneumatic cylinder

  • Hydraulic cylinder

  • Electric actuator with rising stem

Actuator sizing must consider nominal diameter, differential pressure, operating frequency, deposit formation and required closing time.

Applications

Seawater and brackish-water pipelines, lake-water intakes, cooling-water systems and process lines exposed to biological deposits or sediment accumulation. The FB series is selected where pigs, cleaning plugs or inspection devices must pass through the valve without obstruction.

FAQ

When is the FB selected instead of a conventional knife gate valve?
When the pipeline requires an unobstructed bore for pigging, mechanical cleaning or internal inspection.

Which data are required for valve selection?
Nominal diameter, operating pressure, medium, temperature, pressure direction and the dimensions and material of the pigging device.

Standard (Options)
  • DIN
  • ANSI
Material (Options)
  • EN-GJS-400-15 (Nodular Cast Iron)
  • 1.4301
  • 1.4404
  • 1.4408
Pressure Rating (Options)
  • PN 6
  • PN 10
  • PN 16
Seat (Options)
  • NBR

Datasheet and documents

Description

Our full bore knife gate valve combines the proven Wey middle flange design with a completely free passage. Perfectly suited for all applications where pipes and valves need to be cleaned regularly with pigs. Specially designed scrapers remove deposits from the gate every time it is opened. The FB knife gate valve has already been installed in numerous plants for thermal sea or lake water utilization and has proven itself in the fight against the quagga mussel.

Characteristics

  • Nominal sizes: 50 – 2000 mm
  • Material: Stainless steel, Ductile iron
  • Pressure rating: 0 – 10 bar
  • Flange drilling: PN6, PN10, PN16, ANSI Class 150, BS10-D, BS10-E, AS2129-D, AS2129-E
  • Face to face dimension: EN 558 series 20

Details

The robust metal yoke enables the optimal, simple assembly of mechanical or inductive limit switches. The yoke can be removed from one side. This makes it easier to access the mechanical parts.

A completely round passage enables easy pipe cleaning with a pig.

The robust metal yoke enables the optimal, simple assembly of mechanical or inductive limit switches. The yoke can be removed from one side. This makes it easier to access the mechanical parts.

Bronze scrapers clean the gate every time it is opened.

The robust metal yoke enables the optimal, simple assembly of mechanical or inductive limit switches. The yoke can be removed from one side. This makes it easier to access the mechanical parts.

The transverse seal can be repacked at any time and under full pressure using the lateral packing screws.

The robust metal yoke enables the optimal, simple assembly of mechanical or inductive limit switches. The yoke can be removed from one side. This makes it easier to access the mechanical parts.

In the closed end position, the gate is also mechanically supported.

Application Areas

Water treatment

e.g. Seawater, Saltwater ...

Material Of Construction

PartDuctile ironStainless Steel
BodyEN-GJS-400-151.4408
Gate1.43011.4404*
SealNBRNBR
TopworkCarbon steelCarbon steel
Stem / Piston rod1.41041.4104

Other materials upon request  *hard chromed

Corrosion Protection

Body2 Comp. Epoxy-Zinc dust Primer, 2 Comp. Epoxy-Resin iron mica intermediate coat, 2 Comp. Polyurethane-Enamel-Top Coat
Topwork2 Comp. Epoxy-Zinc dust Primer, 2 Comp. Epoxy-Resin iron mica intermediate coat, 2 Comp. Polyurethane-Enamel-Top Coat