Lever-type knife gate valve

Valves of this type should generally be installed horizontally in piping systems.

Lever-type knife gate valves are typically selected for applications requiring rapid manual opening and closing.

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When a gate valve is closed, the sealing surfaces rely solely on the pressure of the medium to achieve a seal—specifically, the sealing surface of the gate is pressed against the valve seat on the opposite side by the medium’s pressure, thereby ensuring a tight seal. This type of sealing is known as self-sealing. By contrast, most gate valves employ forced sealing: when the valve is closed, an external force is used to press the gate against the valve seat, guaranteeing the sealing performance of the sealing surfaces. Such valves should be installed vertically in the pipeline.

Performance

1. The valve can be locally and remotely controlled according to user requirements, and can also provide remote and centralized display.

2. Lightweight: The valve body is made of carbon steel, making it approximately 20%–30% lighter than conventional gate valves, which facilitates installation and maintenance.

3. Using this type of valve can enhance the sealing performance of pipeline systems, minimizing leaks to the greatest extent possible, thereby playing a positive role in improving production efficiency and protecting the environment.

4. The sealing surface is designed with a highly wear-resistant and corrosion-resistant ceramic composite material, using an inlaid technology. This results in superior corrosion resistance and excellent wear resistance, significantly extending the service life of China’s valves and increasing their cost-effectiveness by a factor of 10 compared to conventional valves.

PZG73H, W, Y, TC, X, F, PU
Lever (Rising Stem) Knife Gate Valve
■ Product Overview
Lever-type knife gate valves are typically selected for applications requiring rapid manual opening and closing.

■ Control Instructions
Lever operation requires only manual pulling of the lever to drive the gate plate up and down, thereby opening and closing the valve. Pressing the lever downward raises the gate plate, opening the valve; lifting the lever upward lowers the gate plate, closing the valve.

■ Parameters related to knife gate valves
Sealing structure: unidirectional sealing, bidirectional sealing
Valve structures: exposed disc with exposed stem, concealed disc with exposed stem, through-type, bidirectional opening
Support structures: triangular type, four-column type, steel plate type, concealed plate type, arch bridge type (unique structure)
Connection types: Wafer, flange
Nominal Diameter: DN50–DN3000, NPS 2”–120” (customizable upon request)
Operating temperature: ≤1000℃ (specific temperature resistance depends on the selected material)

Nominal pressure: 0.6 MPa, 1.0 MPa, 1.6 MPa, 2.5 MPa, 5K, 10K, 150LB

Actuating mechanisms: handwheel, pneumatic, pneumohydraulic, electric actuator, electrohydraulic, hydraulic, bevel gear, sprocket, lever

■ Guidance on Sealing Selection for Knife Gate Valves

Sealing type	Valve seat material	Temperature	Applicable Media and Characteristics	Non-applicable operating conditions
Hard Secret Seal	STL	≤500	The cemented carbide has a hardness of 93 HRA, making it suitable for pipelines carrying various particulate media. It features excellent wear resistance and is resistant to deformation.	Hard seals are not suitable for pipelines conveying media containing gases or liquids, as they exhibit large leakage rates and poor sealing performance (Class D). Their use is not recommended in pipelines or operating conditions where even minor internal leaks of gases, liquids, or other micro-media are unacceptable.
	TC	≤300	Ceramics exhibit extremely high resistance to wear, corrosion, and erosion, making them suitable for pipelines conveying various high-intensity particulate media, such as coal slag, coal powder, and high-concentration mineral slurries.
	507	≤425	Metal seals are suitable for various medium- and low-intensity media conditions, such as slag-water mixtures, dust, and bulk materials.
Soft Secret Seal	NBR	≤80	Nitrile rubber is suitable for pipelines conveying various gases and liquid media, with excellent oil resistance and good abrasion resistance.	Not recommended for use in pipelines carrying particulate or solid media. The media can easily damage and wear the rubber body.
	EPDM	≤150	EPDM rubber is suitable for pipelines conveying various gases and liquid media, with excellent acid and alkali resistance and superior abrasion resistance.
	PTFE	≤200	PTFE rubber is suitable for pipelines conveying various gases and liquid media, with excellent acid and alkali resistance as well as outstanding wear resistance.
	PU	≤120	The polyurethane boasts a hardness of 95 HRA and exhibits excellent performance in oil resistance, abrasion resistance, and resistance to low-temperature aging. It is exceptionally wear-resistant, highly resilient, and offers outstanding sealing performance. It is suitable for pipelines conveying various mixed media—including gases, liquids, and particulate materials—and when used in combination, it ensures 100% leak-free operation.	Not recommended for use in sanitary-grade media pipelines.
	PU	≤120		Not recommended for use in sanitary-grade media pipelines.

■ Selection Criteria for Knife Gate Valves
Design and Manufacturing Standards: JB/T 8691-2013, MSS SP-81
Structural length standards: GB/T 15188.2-1994-J21, MSS SP-81

Flange connection standards: GB/T 79, ASME B16.5, GB/T 9113.1-2000

Pressure test standards: JB/T 8691, MSS SP-81

Gate valve grinding standard: GB/T 1184-1996 (Grade 12)

Valve seat precision standard: GB/T 1184-1996 (Grade 11)
Valve stem specification standard: JB/T 8691-2013
Double-head bolt standard: GB899-76
Product identification standard: GB/T12220
Supply specification standard: JB/T7928

■ Material Standards for Knife Gate Valves

Material Selection Standards for Valve Bodies and Components
Part Name	Material Name	Material Grade	National Standard Number
Valve body Pressing strip pressing cover	Ductile iron	QT450-10	GB/T 12227
	Carbon steel	WCB, A305	GB/T 12228, GB/T 12229
	Austenitic stainless steel	CF8, CF3, CF8M, CF3M, 310S	GB/T 12230, GB/T 4237
	Austenitic stainless steel	304, 304L, 316, 316L	ASTM A182:2007, ASTM A240:2007
Valve plate	Austenitic stainless steel	304, 304L, 316, 316L	ASTM A240:2007
Valve plate	Austenitic stainless steel	06Cr19Ni10, 22Cr19Ni10, 06Cr17Ni12Mo2	GB/T 4237
Valve stem	Stainless steel round bar	304, 304L, 316, 316L	ASTM A479:2008
Bracket	Carbon steel	WCB	GB/T 12229
Bracket	Carbon steel	Q235	GB/T 700
Valve stem nut	Copper alloy	ZcuZn38Mn2Pb2, ZcuSn5Pb5Zn5	GB/T 12225
Valve stem nut	Nickel-containing cast iron	D-2	ASTM A439:83(2009)
Packing seal	Graphite braided packing	-	JB/T7370-1994
Valve seat seal ring	Polytetrafluoroethylene	-	HG/T 2903
Valve seat seal ring	Rubber	Fluororubber, nitrile rubber, ethylene propylene diene monomer (EPDM) rubber	-
Handwheel	Carbon steel	25. Q235A	GB/T 699, GB/T 700
Handwheel	Ductile iron	QT400-15, QT450-15	GB/T 12227