Shanghai Liangzheng ValvePZ673H/X/F-10P/16P 304Pneumatic Stainless Steel Knife Gate Valve

I: Product Introduction

The opening and closing component of the pneumatic knife gate valve is the gate plate, whose movement direction is perpendicular to the fluid flow. Manual knife gate valves can only be fully opened or fully closed and cannot be used for regulation or throttling. The gate plate has two sealing surfaces. Commonly used wedge-type gate valves have two sealing surfaces forming a wedge shape, with the wedge angle varying according to valve parameters, typically 50 degrees. The gate plate of a wedge-type knife gate valve can be made as a single unit, known as a rigid gate plate, or it can be designed to allow slight deformation to improve manufacturability and compensate for deviations in the sealing surface angle during processing—this is called an elastic gate plate. When the knife gate valve is closed, the sealing can rely solely on medium pressure, meaning the medium pressure presses the gate plate's sealing surface against the valve seat on the opposite side to ensure a tight seal, which is known as self-sealing. Most knife gate valves use forced sealing, meaning that when the valve is closed, external force is required to press the gate plate against the valve seat to ensure the sealing surface's integrity.

Shanghai Liangzheng ValvePZ673H/X/F-10P/16P 304Pneumatic Stainless Steel Knife Gate Valve

II: Application Range

Pneumatic knife gate valves were introduced in China in the 1980s, and their applications have expanded from general fields to a wide range of industries. They are used in coal selection, gangue discharge, and slag removal in mines and power plants, as well as in urban wastewater treatment. They have evolved from general industrial pipelines to food, sanitary, and other pipeline systems. Knife gate valves offer advantages such as compact size, low flow resistance, light weight, easy installation, and simple disassembly, addressing the issues of high flow resistance, heavy weight, difficult installation, and large footprint associated with conventional gate valves, flat gate valves, ball valves, globe valves, control valves, and butterfly valves. Since their introduction, knife gate valves have largely replaced many general-purpose shut-off and control valves.

Shanghai Liangzheng ValvePZ673H/X/F-10P/16P 304Pneumatic Stainless Steel Knife Gate Valve

III: Performance

Pneumatic knife gate valves feature a simple and compact structure, rational design, lightweight material usage, excellent sealing, easy and flexible operation, small size, smooth flow passage, low flow resistance, light weight, easy installation, and simple disassembly. The gate plate of the knife gate valve has a shearing function, capable of scraping off adhesions on the sealing surface and automatically removing debris. The stainless steel gate plate prevents sealing leakage caused by corrosion.

Shanghai Liangzheng ValvePZ673H/X/F-10P/16P 304Pneumatic Stainless Steel Knife Gate Valve

IV: Installation and Use

1. Before installation, inspect the valve cavity and sealing surfaces to ensure no dirt or sand particles are attached; this type of valve should generally be installed horizontally in the pipeline.

2. Bolts at all connection points should be tightened evenly.

3. Ensure the packing is compressed properly to maintain sealing integrity while allowing smooth opening of the gate plate.

4. Before installation, verify the valve model, connection dimensions, and medium flow direction to ensure compatibility with valve requirements.

5. Reserve necessary space for valve actuation during installation.

6. Wiring for the actuation device must follow the circuit diagram.

7. Perform regular maintenance on the pneumatic knife gate valve; avoid impact and compression to prevent affecting the seal.

Shanghai Liangzheng ValvePZ673H/X/F-10P/16P 304Pneumatic Stainless Steel Knife Gate Valve

V: Features

1. Pneumatic knife gate valves are available in non-rising stem and rising stem designs depending on the diameter (non-rising stem DN50–900mm, rising stem DN50–900mm). The full-round straight flow channel design prevents residue accumulation and jamming. The bottom edge of the gate plate is sharpened to cut through soft materials like fibers, pulp, and wood pulp, while ensuring smooth opening and closing. A hard PTFE scraper installed on the upper part of the gate plate prevents abrasive materials such as dust and grit from entering the stuffing box, extending the gate plate's service life. The gate plate is made of stainless steel, precision ground and polished for excellent sealing. The valve is compact, space-saving, lightweight, cost-effective, easy to install, equipped with wear and clogging prevention measures, easy to maintain, user-friendly, durable, and compatible with various actuation devices.

2. The valve body and stuffing box are precision cast. The valve body is flanged and integrally cast, with material options including 304, 316, 316L, WCB, and 2Cr13 based on user requirements. The sealing ring is made of PTFE (polytetrafluoroethylene), offering corrosion resistance, wear resistance, and non-stick properties.

3. The gate plate has five support points, ensuring excellent self-alignment. When the valve is closed and under back pressure, the gate plate does not shift.

4. The internal passage of the pneumatic knife gate valve can be designed in V-shape, triangular, or pentagonal configurations. The V-shaped gate plate can be used for regulation and control.

5. Connection types include wafer-type and flanged lug-type. Sealing options include metal-to-metal hard sealing, metal-to-polyurethane, and PTFE soft sealing.

6. Suitable media: gold ore powder, tailings, pulp, wood pulp, fibers, dust, chemically treated wastewater, sedimentation tanks, ore sand, slag, coal slurry, asphalt, silo outlets, fruits, grains, cement slurry, slaughterhouse wastewater, etc.