What is the difference between knife gate valve and gate valve?

Knife gate: thin sharp blade, handles slurry/solids, full bore no cavity, resilient seat (EPDM/PTFE), MSS SP-81, PN10-PN16. Conventional gate: thick wedge, clean fluids only, body cavity, metal seat, API 600/602, up to Class 2500.

MSS SP-81 is the primary design standard for knife gate valves. Covers design, dimensions, materials, testing. Specifies face-to-face dimensions, pressure-temperature ratings, hydrostatic test (body 1.5x, seat 1.1x rated pressure).

Slurry & Isolation

Knife Edge Gate Valve – Wafer & Flanged Type

Name: Knife Edge Gate Valve (Knife Gate Valve)
Brand: Supreme Valves
SKU: SV-KNIFEEDGEGATEVALVE
Price: 3500 INR
Availability: InStock
Rating: 4.8 (127 reviews)

SUPREME Make Knife Edge Gate Valve – also known as Knife Gate Valve. Sharp-edged blade cuts through slurry, pulp, and viscous media. Available in Wafer and Flanged body styles. GGG40, WCB, or SS316 body. SS 304 knife. EPDM / PTFE seat. PN10, PN16, Class 150, Class 300. Sizes DN50 to DN600. Design per MSS SP-81. Manual, gear, or AUMA electric actuator.

Quick Summary

Knife Edge Gate Valve = Valve with sharp-edged blade that cuts through thick media for shut-off. Ideal for slurry, wastewater, pulp, mining, cement, ash handling. Wafer type = compact, lightweight. Flanged type = heavier, end-of-line capable. GGG40 body + SS304 knife + EPDM/PTFE seat. PN10 wafer prices from ₹9,737 (DN100) to ₹19,838 (DN200). AUMA actuator adds ₹25,000.

How It Works

The hand wheel or actuator rotates the stem, moving the thin, sharp-edged knife vertically through the flow path. The knife cuts through solids, fibres, or slurry and seats into the resilient EPDM/PTFE seat for a bubble-tight seal (Leakage Class IV). Bonnetless design = knife retracts above body = full bore, unobstructed flow when open. This cutting action handles media that would jam conventional gate valves.

Knife Edge Gate Valve Wafer Flanged GGG40 SS304

In Stock AUMA Option Export Ready

Key Specifications

Type: Knife Edge Gate

Body Styles: Wafer, Flanged

Pressure: PN10, PN16, CL150, CL300

Body: GGG40 / WCB / SS316

Knife: SS 304 / SS 316

Seat: EPDM / PTFE / NBR / Metal

Leakage: Class IV (soft seat)

Design: MSS SP-81

Sizes: DN50 to DN600

Operation: HW / Gear / AUMA

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Export Ready: We export to UAE, Middle East, Africa, and Asia. Complete documentation including MTCs, test reports, and GAD.

Wafer vs Flanged – Which Type to Choose?

Feature	Wafer Type	Flanged Type
Connection	Sandwiched between flanges	Integral flanges bolted to pipe
Weight	Lighter (30-50% less)	Heavier
Cost	More economical	Higher cost
End-of-Line Use	Not suitable	Suitable
Removal	Requires both flanges loosened	Easy individual removal
Best For	Cost-sensitive, inline isolation	Critical service, large sizes

Price Schedule – PN10 Wafer Type (GGG40 / SS304 / EPDM)

Manual Hand Wheel Operated

Size	Rating	Body	Knife	Seat	Price (INR/pc)
DN100 (4")	PN10	GGG40	SS 304	EPDM	₹9,737
DN150 (6")	PN10	GGG40	SS 304	EPDM	₹12,194
DN200 (8")	PN10	GGG40	SS 304	EPDM	₹19,838

AUMA Actuator Operated (24V DC, ON-OFF + Proximity Sensors)

Size	Rating	Valve (INR)	AUMA Actuator (INR)	Total per PC (INR)
DN100 (4")	PN10	₹9,737	₹25,000	₹34,737

All prices Ex-Works Ahmedabad. GST extra. Delivery: 2-3 weeks from PO & drawing approval. Flanged type and other sizes on request.

Technical Specifications

Valve Type	Knife Edge Gate Valve (Knife Gate Valve)
Body Styles	Wafer Type, Flanged Type
Pressure Rating	PN10, PN16, Class 150, Class 300
Available Sizes	DN50 (2") to DN600 (24")
Body Material	GGG40 (Ductile Iron), WCB (Carbon Steel), CF8M (SS316), Cast Iron
Gate / Knife	SS 304, SS 316, Hastelloy
Seat Options	EPDM (Bi-directional), PTFE, NBR, Metal-to-Metal
Leakage Class	Class IV (soft seat), Class V (metal seat)
Design Standard	MSS SP-81
Testing Standard	MSS SP-81 / API 598
Face-to-Face	MSS SP-81 (Wafer), ASME B16.10 (Flanged)
Flange Drilling	ASME B16.5, EN 1092-1, IS 6392
Operation	Hand Wheel, Bevel Gear, AUMA Electric (24V DC / 415V AC), Pneumatic, Hydraulic
Temperature Range	-40°C to +120°C (EPDM), -200°C to +260°C (PTFE), up to +425°C (Metal seat)
Painting	Industrial Epoxy Coating
Warranty	12 months from supply or 18 months from dispatch

Test Pressure

Test Type	PN10 (kg/cm²)	Class 150 (PSI)	Standard
Hydrostatic – Body	30	425	MSS SP-81
Hydrostatic – Seat	22	300	MSS SP-81
Air Test – Seat	7	100	MSS SP-81

Bill of Material (MOC)

Sr.	Component	Standard MOC	Alternate MOC
01	Body	GGG40 (Ductile Iron)	WCB, CF8M (SS316), Cast Iron
02	Gate / Knife	SS 304	SS 316, Hastelloy
03	Seat	EPDM (Bi-directional)	PTFE, NBR, Metal
04	Gland Packing	PTFE	Graphite
05	Shaft / Stem	SS 304	SS 316
06	Yoke	MS, Epoxy Coated	SS 304
07	Sleeve	Gun Metal (GM)	Bronze
08	Hand Wheel	SGI	–
09	Fasteners	MS / SS	A193 B7 / B8
10	Actuator (Optional)	AUMA, 24V DC, ON-OFF	Pneumatic, Hydraulic

GAD – Dimensional Data (mm) – Wafer Type

End detail: Wafer to suit ASME B16.5. Standard: MSS SP-81.

Size	DN	L	ØD	ØC	B	ØJ	PCD
2"	50	48	60	50	12	12	120.6
2.5"	65	48	70	65	12	12	139.7
3"	80	51	80	75	12	12	152.4
4"	100	51	135	100	12	18	190.5
5"	125	58	110	125	15	18	215.9
6"	150	58	160	150	15	18	241.3
8"	200	70	210	200	15	18	298.4

L = Face-to-Face, ØD = Body OD, ØC = Bore, B = Body Thickness, ØJ = Bolt Hole Dia, PCD = Pitch Circle Diameter. Green rows = sizes with pricing. Flanged dimensions on request.

Applications

Wastewater Treatment

Pulp & Paper

Mining & Slurry

Cement & Ash Handling

Power Plants

Chemical Processing

Food Processing

Water Treatment

Commercial Terms

Price Basis

Ex-Works, Ahmedabad. GST extra.

Delivery

2-3 weeks from PO & drawing approval.

Payment

50% advance, 50% before dispatch.

Warranty

12 months from supply or 18 months from dispatch.

Documents Provided After PO

Valve Datasheet

GAD Drawing

Material Test Certificates

Pressure Test Report

Actuator Datasheet (AUMA)

Frequently Asked Questions

What is a knife edge gate valve?

A knife edge gate valve (knife gate valve) has a sharp-edged blade that cuts through thick media for shut-off. Designed for slurry, pulp, wastewater, mining tailings. The knife edge cuts through solids that would jam conventional gate valves. Available in wafer (compact) and flanged (end-of-line capable) types.

Knife gate valve vs conventional gate valve?

Knife gate = thin sharp blade, handles slurry/solids, full bore, resilient seat, MSS SP-81, PN10-PN16. Conventional gate = thick wedge, clean fluids only, body cavity, metal seat, API 600, up to Class 2500.

What is the price of knife edge gate valve?

PN10 wafer (GGG40/SS304/EPDM): DN100 = ₹9,737, DN150 = ₹12,194, DN200 = ₹19,838. DN100 with AUMA actuator = ₹34,737. All Ex-Works India. Delivery 2-3 weeks.

Wafer vs flanged knife gate valve?

Wafer = sandwiched between flanges, lighter, cheaper, cannot be end-of-line. Flanged = integral flanges, heavier, costlier, can be end-of-line, easier removal. Use wafer for cost-sensitive inline. Use flanged for critical service.

What is MSS SP-81?

MSS SP-81 is the primary design standard for knife gate valves. Covers design, dimensions, materials, testing. Body test 1.5x rated pressure, seat test 1.1x rated pressure.

What materials are available?

Body: GGG40, WCB, CF8M (SS316). Knife: SS304, SS316, Hastelloy. Seat: EPDM (-40 to +120°C), PTFE (-200 to +260°C), NBR (oil), Metal (high temp). Stem: SS304/316.

What is EPDM bi-directional seat?

EPDM bi-directional seat seals both directions. Bubble-tight shut-off (Leakage Class IV), -40 to +120°C, self-cleaning as knife cuts through seat.

What actuators are available?

Hand wheel (standard), bevel gear (DN300+), AUMA electric (24V DC / 415V AC, ON-OFF / modulating, proximity sensors), pneumatic, hydraulic. AUMA adds ₹25,000 per valve.

Need Knife Edge Gate Valves?

Wafer and flanged types with AUMA actuators. Export to UAE, Middle East, Africa. Complete documentation.