Gate valve classification features and design standards installation applications

Gate valve applications.

The opening and closing member of the gate valve is the gate, the direction of movement of the gate is perpendicular to the direction of the fluid, used as a cut-off medium, the entire flow through when fully open, when the medium runs small pressure loss. Gate valve is usually used in the case where it is not necessary to open and close frequently, and to keep the gate fully open or fully closed, not suitable for use as regulation or throttling. Gate valve fluid resistance is small, the applicable pressure, temperature range, media flow direction is not restricted, good sealing performance. Widely used in food, medicine, petroleum, chemical, natural gas, steel, environmental protection, paper and other transport pipeline to do media cut off or circulation.

Gate valve classification.

Types of gate valves, according to the configuration of the sealing surface can be divided into wedge gate type gate valve and parallel gate type gate valve, wedge gate type gate valve can be divided into: single gate, double gate type and resilient gate type; parallel gate type gate valve can be divided into single gate type and double gate type. According to the thread position of the stem, it can be divided into two kinds of open stem gate valve and concealed stem gate valve. This type of valve in the pipeline should generally be installed horizontally.

Gate valve working principle.

Turn the handwheel, through the handwheel and the thread of the Fashion design wall mounted quick open tap stem in and out, lifting or lowering the valve plate connected with the stem, to open and close the role.

Gate valve design notes.

1, valve cover gasket form

Class150 gate valve adopts stainless steel graphite composite gasket; Class300 gate valve adopts stainless steel graphite wound gasket; Class600 gate valve can use stainless steel graphite wound gasket or metal ring gasket; Class900 gate valve adopts metal ring gasket; Class1500/Class2500 gate valve adopts gate valve adopts self-pressure sealing metal ring.

2, valve body and cover connection form

Bolt-on bonnet BB, body cover welded BW, self-pressure sealing bonnet PS 

3,Spring loaded packing impact system

Spring loaded packing impact system can be used to improve the durability and reliability of the packing seal according to customer requirements.

4,Gate design form

NPS≤2in (DN50) can use rigid gate; NPS≥2in (DN50) can use elastic gate

5, Inverted seal design

The gate valve produced by our company adopts inverted seal design, usually, the seat design of carbon steel gate valve adopts separated inverted seal structure, and the inverted seal type of stainless steel gate valve is directly processed or processed after welding. When the valve is fully open, the sealing surface of the inverted seal is very reliable.

6, stem design

Our gate valve stem is made of integral forging process, the stem is tempered and surface nitriding treatment, has good corrosion resistance, anti-scuffing and wear resistance, in accordance with the standard requirements to determine the small diameter, the stem and the gate is connected by T-shaped structure.

7, valve seat design

Carbon steel gate valve seat is usually made of forged steel, seat seal material can be spray welded carbide according to the user's requirements. According to the customer's requirements, the valve seat can be separated threaded screw-in seat, welded seat and the body directly processed seat.

8,Bypass valve design structure

The gate valve with bypass valve should be opened before opening (to balance the pressure difference between the import and export and reduce the opening force).