Forged steel gate valve

Introduction The gate of the gate valve is a gate. The direction of movement of the gate is perpendicular to the direction of the flow. The gate valve can only be fully opened and fully closed and cannot be adjusted or throttled. The direction of gate movement of the gate valve is perpendicular to the direction of the flow. The gate valve can only be fully opened and fully closed, and it cannot be adjusted or throttled. The gate has two sealing surfaces. The two sealing surfaces of the most commonly used mode gate valves form a wedge, and the wedge angle varies with the valve parameters. Gate valve drive classification: manual gate valve, pneumatic gate valve, electric gate valve.

Forged steel gate valve: It is all gate valves made of forging materials and are collectively referred to as forged steel gate valves. Forging materials include A105, F11, F5, 304, 304L, 316, and 316L. Domestic forging steel gate valve usually refers to small diameter forged steel gate valve, diameter range: DN10 ~ DN50; pressure range: national standard PN16 ~ PN320, American standard: Class150 ~ 2500, can adopt American standard or national standard size production and processing, manufacturers are Available from stock. The forged steel gate valves that exceed the DN50 caliber are all required to be customized, with less domestic demand.

There are many different ways of classifying structure classification gate valves. The main difference is that the structure of the sealing elements used is different. According to the structure of sealing elements, gate valves are often divided into several different types. The most common form is parallel type. Gate valve and gate valve; According to the structure of the valve stem, it can be divided into open and closed gate valves. Forged steel gate valve Forging steel gate valve Suitable for Class 150～2500, working temperature: -29～425°C (carbon steel) or -29～ 500 °C (stainless steel) on the small diameter pipeline, used to cut off or connect the medium in the pipeline, use different materials, can be applied to water, steam, oil, acetic acid, oxidizing medium, urea and other medium. More applications in the oil pipeline.

Forged Steel Gate Valves Features Forged steel gate valves are mostly designed for reducing diameters in Dalian. Compared with cast steel gate valves of the same caliber, the flow rate is slightly lower, but the pressure and temperature range is higher than that of cast steel valves, and the sealing performance is also higher than that of cast steel gate valves. The steel gate valve is much better and has a longer life. The flow direction of the medium is the same as other gate valves.

Installation points 1. The installation position, height, and direction of import and export must meet the design requirements and the connection should be firm and tight.

2. All types of manual valves installed on the insulation pipe shall not be downwards.

3, the appearance of the valve must be checked before installation, the nameplate of the valve should comply with the provisions of the current national standard "General Valve Marking" GB12220. For valves with a working pressure greater than 1.0 MPa and a shut-off effect on the main pipe, strength and tight performance tests shall be performed before installation. In the strength test, the test pressure is 1.5 times the nominal pressure, and the duration is not less than 5 minutes. The valve housing and the packing should have no leakage as qualified. In the stringency test, the test pressure is 1.1 times the nominal pressure; the test pressure shall meet the requirements of GB50243 standard for the duration of the test, and no leakage of the sealing surface of the gate is acceptable.

Forged steel gate valve implementation of standard design specifications: JB/T7746, API602

Structure length: JB/T7746, factory specification socket/thread: JB/T1751/GB7306, ANSIB16.11/B2.1

Test and Inspection: JB/T9092, API598

Pressure-Temperature: GB/T 9131, ANSI B 16.34

Product ID: GB/T12220, MSSSP25

Supply specification: JB/T7928

The standards produced by major manufacturers in China are not the same. For example, the lengths and production standards of American Standard Gate Valves produced by Shanghai Gaogao Valve Co., Ltd., formerly Shanghai Minhang High and Intermediate Pressure Valve Factory and Shanghai Liangzhong Valve Factory, are not the same. Forged steel gate valves often neglect pressure problems. During the grease injection operation, the pressure of the injection-regulating half-free float ball steam trap is changed by peaks and valleys. If the pressure is too low, the seal leaks or the safety valve fails, the pressure is too high, the grease injection valve is blocked, the internal grease is hardened, the seal ring and the valve ball, and the valve plate is locked. When the injection pressure is too low, the injected grease flows into the bottom of the valve chamber, which usually occurs in the small gate valve. The fat injection flow control valve pressure is too high, on the one hand to check the thermal insulation valve check grease injection mouth, if fat is blocked, the remote control float valve hole is closed and the spring is closed and the wrench is fully opened to replace; the other is a plunger stop valve on the one hand fat To harden, use a cleaning fluid, repeatedly soften the defective sealing grease, and inject new grease to replace it. In addition, the sealing type and the sealing material also affect the injection pressure. Different sealing types have different injection pressures. In general, the hard sealing pressure is higher than the soft sealing.