API · ASME · DIN · EN standard industrial valves
Knife Gate Valves
Knife gate valves cut through pulp, slurry, chip and other media that would jam a wedge gate: a thin blade-style disc with a sharpened edge drops through the medium and seats into a soft seal ring, keeping the valve short, light and cheap per size. The series is a unidirectional design at DN50 to DN450, PN10, in carbon steel, ductile iron or SS316 bodies with SS304/SS316 blades and polyurethane, EPDM, NBR or Viton seal rings. Ends are wafer or lug; operation is handwheel, electric or pneumatic actuated. Design and manufacture are per MSS SP-81 with face-to-face per the same standard, flanged connections per DIN and JIS, and testing to API 598. Bi-directional and slurry variants exist in the same family.
Part of the Gate Valves family
Last updated: 2026-11
Family specifications
| size range | DN50 to DN450 |
|---|---|
| pressure class | PN10 (Class 150 body option in collected tables) |
| body materials | Carbon steel, Ductile iron, SS316 |
| disc materials | SS304, SS316, SS316L |
| end connections | Wafer type, Lug type |
| operation | Handwheel, Electric actuated, Pneumatic actuated |
| temperature range | -20°C to 80°C |
| design standards | MSS SP-81 |
| testing standards | API 598 |
| seal materials | Polyurethane, EPDM, NBR, VITON |
| flow direction | Unidirectional |
| kgv structure | Bidirectional knife gate valve, wafer type |
| kgv nominal size | DN50 (2 inch) |
| kgv design pressure | PN10, PN16, Class 150 LB |
| kgv temperature range | -29 deg C to 120 deg C |
| kgv max working pressure | DN50-DN250: 10 bar; DN300-DN450: 7 bar |
| kgv body materials | GGG40, ASTM A351 CF8, CF8M, special alloys |
| kgv disc materials | Stainless steel chrome plated, special alloys |
| kgv seat materials | EPDM (120 deg C), NBR (80 deg C) |
| kgv flange standards | GB/T 9113.1, JB/T 79.1, HG 20592, ASME B16.5, EN 1092-1 |
| kgv face to face | MSS SP-81 |
| kgv operation options | Manual, pneumatic, electric, hydraulic |
| kgw nominal size | DN150 (6 inch) |
| kgw design pressure | PN16, Class 150 LB |
| kgw size range | NPS 2-24 inch (DN50-DN600) |
| kgw max working pressure | DN50-DN250: 10 bar; DN300-DN450: 7 bar; DN500-DN600: 4 bar |
| kgw temperature range | -29 deg C to 538 deg C |
| kgw body materials | Carbon steel, stainless steel, special alloy |
| kgw disc materials | Stainless steel chrome plated, special alloy |
| kgw seat materials | Stainless steel + cobalt-chromium hardfacing alloy; EPDM (120 deg C); Viton (200 deg C); PTFE (200 deg C); NBR (80 deg C) |
| kgw flange standards | GB/T 9113.1, JB/T 79.1, HG 20592, ASME B16.5, EN 1092-1 |
| kgw face to face | MSS SP-81 |
| kgw flow direction | Unidirectional, rising stem |
| kgw medium | Pulp, coal ash, sewage, food |
| kgx size range | DN50-DN450 (2-18 inch) |
| kgx pressure rating | 150 LB |
| kgx body material | SS410 |
| kgx stem material | Stainless steel 304 |
| kgx temperature range | -20 to 100 deg C |
| kgy size range | DN50-DN400 |
| kgy pressure rating | PN10/PN16 |
| kgy body material | Ductile iron |
| kgy seal materials | SS304/SS316 + EPDM |
| kgy stem material | Stainless steel 304 |
| kgy temperature range | 0-80 deg C |
| kgy medium | Water, oil, gas |
| kcm size range | 2-48 inch (DN50-DN1200) |
| kcm pressure rating | Class 150, PN10, PN16 |
| kcm body options | Integral body, two pieces body; bolt bonnet available |
| kcm stem types | Rising stem, non-rising stem (NRS) |
| kcm flow direction | Bi-directional |
| kcm operators | Bevel gear box, pneumatic cylinder, electrical, hydraulic, chain-wheel |
| kcm body materials | WCB, CF8, CF8M, SS2205, 904L |
| kcm seat materials | 20Cr13, SS304, SS316, 904L, SS2205, NBR, EPDM |
| kcm gate materials | 20Cr13, SS304, SS316, 904L, SS2205 |
| kcm stem material | 2Cr13 |
| kcm stem nut material | Brass |
| kcm stem packing | PTFE |
| kcm applications | Syrup, pulp, sewage, slurry, dust |
| kcn pressure rating | Class 150, PN10, PN16 |
| kcn connection types | Flanged wafer or lug, semi-lug |
| kcn stem types | Ring stem, non-rising stem type |
| kcn flow direction | Uni-direction, bi-direction flow |
| kcn operators | Manual handwheel, bevel gear, pneumatic, hydraulic, electric motor, chain wheel |
| kcn body materials | A216 WCB, A351 CF8, A351 CF8M |
| kcn gate materials | 20Cr13, SS304, SS316, 904L, SS2205 |
| kcn stem material | 2Cr13 |
| kcn stem packing | PTFE |
| kcn handwheel material | Ductile iron |
| nkg standard basis | Standard basis (MSS SP-81, ASME B16.34) to be confirmed for the selected series or configuration |
| nkg connection options | Wafer, lug or flanged, selected design dependent |
| nkg review inputs | Service medium, solids, pressure and maximum differential pressure, temperature, shutoff direction, connection, material or seat requirements, actuation, testing and document requirements, quantity |
Ordering & documentation
Documents
Ask for the documentation set with the inquiry — typical items (material certificates, test reports to the listed inspection standard, dimensional drawings) are confirmed and supplied with the quotation.
Quotation
Send the medium, temperature, pressure, size and connection for a quotation-ready inquiry. Lead time, MOQ and price are confirmed at quotation, together with the documents to be supplied with the order.
Sample & supply
Supply terms, order quantities and lead time are agreed per order — state the destination country and required schedule with the inquiry.
Storage & shipping
Store valves with seats and seals protected from UV, ozone and deformation, and keep end-face protectors on until installation; storage limits and shipping arrangements for the selected materials are confirmed at quotation.
Frequently asked questions
What standards govern the design and testing of knife gate valves?
The published specification for this family lists MSS SP-81 as the design standards. Testing follows API 598.
What sizes and pressure ratings are available for knife gate valves?
The published size range is DN50 to DN450, and the published pressure ratings are PN10 (Class 150 body option in collected tables). Availability of a specific size and rating is confirmed at quotation.
What materials are knife gate valves available in?
The published specification lists body materials: Carbon steel, Ductile iron, SS316. Material availability for a specific size and rating is confirmed at quotation.
What working temperature range do knife gate valves cover?
The published working temperature range is -20°C to 80°C. For a medium at the edge of the range, confirm the suitability of the selected seat and body materials at quotation.
What end connections do knife gate valves support?
The published specification lists Wafer type, Lug type as the available end connections. The connection for a specific size is confirmed at quotation.
What should a quotation inquiry for knife gate valves include?
The governing standard and class, nominal size, body and seat materials, the service medium with temperature, and the destination — anything missing is confirmed during quotation.
Knowledge: selection guides
Models & executions in this subtype
Model
Unidirectional Knife Gate Valves
Unidirectional knife gate valves seal on one side only: a thin blade gate pushes into an elastomer seal (polyurethane, EPDM, NBR or Viton on the benchmark page)
View specifications →Model
Bi-Directional Knife Gate Valves
A bi-directional knife gate execution to MSS SP-81: the gate seals in both flow directions, so it can be installed without regard to flow orientation - the prac
View specifications →Request a quote for knife gate valves
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