Knife Gate Valves - MH Series | Wey Valves | PN25 Slurry Service
Knife Gate Valves - MH Series | Wey Valves | PN25 Slurry Service

Knife Gate Valves - MH Series | Wey Valves

WEY MH Knife Gate Valve – PN25 Service

The WEY MH series is a bidirectional isolation valve for slurry, sludge, viscous products and solids-bearing media at pressures up to 25 bar. The gate is guided throughout its travel and mechanically supported in the closed position to limit deformation under differential pressure.

Technical Data

  • Nominal sizes: DN100–DN400

  • Operating pressure: up to 25 bar

  • Flange connections: PN25, ASME Class 150 or Class 300

  • Face-to-face dimension: EN 558 / ISO 5752, Series 16

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

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

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

  • Seat seals: NBR; EPDM, FKM or PTFE options

The double transverse sealing arrangement includes two scrapers to control leakage to atmosphere and remove deposits from the gate surface. The circular seat seal is mechanically retained, while the guide geometry directs accumulated solids back into the flow during opening.

Actuator Options

  • MHA: handwheel or bevel gearbox

  • MHC: double-acting pneumatic cylinder, 6–8 bar

  • MHE: electric actuator

  • MHH: double-acting hydraulic cylinder

Actuator thrust must be calculated according to nominal diameter, differential pressure, solids concentration and required operating time.

Applications

Mining slurry, tailings, process water, phosphates, acids, bitumen, wastewater, digested sludge, pulp and chemical solutions.

FAQ

What is the difference between the MH and MG series?
The MH covers pressures up to 25 bar and uses a Series 16 face-to-face dimension. The MG covers pressures up to 16 bar with a Series 20 dimension.

How is transverse seal leakage corrected?
The lateral compression screws are tightened uniformly in small increments to restore sealing without causing excessive gate friction.

Standard (Options)
  • DIN
  • ANSI
Material (Options)
  • EN-GJS-400-15 (Nodular Cast Iron)
  • 1.4301
  • 1.4404
  • 1.4408
Pressure Rating (Options)
  • PN 25
Seat (Options)
  • NBR

Datasheet and documents

Description

The MH series is designed for extremely high pressures in particularly demanding applications. The original Wey design ensures optimal sealing in the seat and is 100% bubble-tight, regardless of pressure, medium, or on/off cycle.

Characteristics

  • Nominal sizes: 100 – 400 mm
  • Material: Stainless steel, Ductile iron, Special material
  • Pressure rating: 0 – 25 bar
  • Flange drilling: PN25, ANSI Class 150, ANSI Class 300
  • Face to face dimension: EN 558 series 16

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 unique transverse seal, consisting of a transverse seal profile and packing compound, makes the body bubble-tight towards the atmosphere.

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 mechanically retained round cord seal creates a bubble-tight shut off on the gate edge.

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.

Robust 4-post topwork for maximum load and a wide variety of actuator types.

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.

Most known pipe-cleaning methods (e.g., pigs, brush cylinders, etc.) can be used with the body bore, resulting in minimal pressure drops.

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.

With its optimized gate geometry, accumulated media is pushed out of the gate guide and flushed out into the bore by the increased flow.

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 gate is mechanically guided over the full stroke.

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

Mining

e.g. Coal dust, Mining slurry, Sinter water, Tailings, Acids and phosphates ...

Infrastructure

e.g. Waste water ...

Pulp and paper industry

e.g. Pulp Stock (Low to high density), Liquor (black, white, green), Chemical solutions, bleaching agents, Recycling tissue ...

Chemical and petrochemical industries

e.g. Viscous pastes, Granulates, Chemically contaminated waste water, Bitumen/tar ...

Coal fired power stations

e.g. Coal slurry ...

Waste water treatment plants

e.g. Raw water, Sludge, Digested sludge ...

Material Of Construction

PartCast 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-Polyamide Resin Primer, 2 Comp. Polyurethane-Enamel-Top Coat
Topwork2 Comp. Epoxy-Polyamide Resin Primer, 2 Comp. Polyurethane-Enamel-Top Coat