Forged Steel Flange End Gate Valve

Product description
Type (Channel Location): Straight-through Standard: National Standard; Nominal Path: 40 (mm)
Main Material: A105 Working Temperature: Normal Temperature Material: A105
Flow Direction: One-way Pressure Environment: High Pressure Parts and Accessories: Accessories
Type: Forged Steel Flange End Gate Valve Connection Form: Flange Seal Form: Hard Seal Type
Usage: Cut-off Brand: Keep winning. Applicable medium: water
Drive mode: manual shape: miniature
Product Overview
The gate valve's opening and closing part is the gate. The movement direction of the gate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and closed, and can not be adjusted and throttled. The gate has two sealing surfaces. The two sealing surfaces of the most commonly used mode gate valves form wedges, and the wedge angle varies with the valve parameters. The driving modes of gate valves are classified as manual gate valves, pneumatic gate valves and electric gate valves. The materials of gate valves are cast iron gate valves, ductile iron gate valves, stainless steel gate valves, forged steel gate valves, etc. Gate valve refers to the valve whose closing part (gate) moves vertically along the central line of the passage. Gate valves are mainly used for cutting off in pipelines. Forged steel gate valve is a kind of valve widely used. It is usually used for cutting device with diameter DN (> 50mm), and sometimes for cutting device with very small diameter. Gate valves, as a kind of lower grade valves, are more common.
I. Advantages of gate valves
1. Low fluid resistance.
2. Opening and closing require less external force.
3. The flow direction of media is not limited.
4. When fully open, the erosion of sealing surface by working medium is smaller than that of globe valve.
5. Simple shape and good casting technology.
2. Disadvantages of gate valves
1. The shape size and opening height are larger. The installation space is large.
2. In the process of opening and closing, there is relative friction between the sealing surfaces, which easily causes abrasion.
3. Gate valves generally have two sealing surfaces, which make it difficult to process, grind and maintain.
According to the configuration of sealing surface, wedge gate valves can be divided into wedge gate valves and parallel gate valves. Wedge gate valves can be divided into single gate, double gate and elastic gate; parallel gate valves can be divided into single gate and double gate.
1) Parallel gate valve: The sealing surface is parallel to the vertical central line, that is, the two sealing surfaces are parallel to each other. Among parallel gate valves, the structure with thrust wedges is the most common one. There are double thrust wedges between the two gates. This kind of gate valve is suitable for low pressure small and medium diameter (DN40-300mm) gate valves. There are also springs between the two gates, which can produce a tightening force, which is conducive to the sealing of the gates.
2) Wedge gate valve: the sealing surface and the vertical center line into a certain angle, that is, two sealing surfaces into wedge-shaped gate valve. The inclination angle of sealing surface is generally 2 52, 3 30, 5 8 and 10 etc. The magnitude of the inclination angle mainly depends on the medium temperature. Generally, the higher the working temperature is, the larger the angle should be, so as to reduce the possibility of wedging when the temperature changes. In wedge gate valves, there are single gate, double gate and elastic gate. Single gate wedge gate valve is simple in structure and reliable in use, but it requires higher accuracy of sealing surface angle, and it is difficult to process and maintain. The possibility of wedging is great when the temperature changes. Double wedge gate valves are widely used in water and steam medium pipelines. Its advantages are: low accuracy requirement for the angle of the sealing surface, temperature change is not easy to cause wedge phenomenon, when the sealing surface wears, gaskets can be added to compensate. However, there are many structural parts, which are easy to bond in viscous media and affect the sealing. More importantly, the upper and lower baffles are easy to rust and fall off after long-term use. Elastic wedge gate valve, which has the advantages of simple structure and reliable use of single wedge gate valve, can produce a small amount of elastic deformation to compensate for the deviation caused by the angle processing of sealing surface and improve the technicality, has been widely used.