Flanged Gate Valve

Flanged gate valve refers to the gate valve in which all the connection between the valve body and the bonnet is flanged. The type of flange sealing surface can be flat, concave-convex, tenon-groove or trapezoidal-groove, and is specified in the order contract. Indicate the type of sealing surface.

Common valve connections include:

Flange connection, wafer connection, butt welding connection, threaded connection, ferrule connection, clamp connection, self-sealing connection and other connection forms.

Flange connection: the valve body has flanges at both ends, corresponding to the flanges on the pipeline, and is installed in the pipeline by bolting the flanges. Flange connection is the most used connection form in valves. Flanges have convex surface (RF), flat surface (FF), convex and concave surface (MF), etc.

Flanged gate valves can be divided into the following types according to the shape of the joint surface:

1) Smooth type: used for valves with low pressure. Processing is more convenient

2) Concave-convex type: high working pressure, medium and hard washers can be used

3) Tongue and groove type: gaskets with larger plastic deformation can be used, which are widely used in corrosive media and have better sealing effect.

4) Trapezoidal groove type: use an oval metal ring as a gasket, used for valves with a working pressure of ≥64 kg/cm², or high temperature valves.

5) Lens type: The gasket is in the shape of a lens and is made of metal. It is used for high-pressure valves or high-temperature valves with a working pressure of ≥100 kg/cm².

6) O-ring type: This is a newer flange connection form, which is developed with the emergence of various rubber O-rings, and it is more reliable than ordinary flat washers in terms of sealing effect.

Flange gates have the following types, which should be indicated in the order contract:

a) Wedge-type single gate;

b) Wedge type double gate;

c) Parallel double gate.

Body, bonnet and gate for flanged gate

1. The valve body, bonnet and gate must have guide rails or guide grooves, so that the gate moves along the guide grooves of the valve body and the bonnet during the opening and closing process of the valve, so as to ensure that when the gate is in any position, the gate will not move. The symmetrical centerline of the sealing surface is aligned with the stem axis, which minimizes the wear of the sealing surface.

2. The sealing surface of the valve body and gate can be directly processed on the valve body and gate, or surfacing with other metals. The thickness of the surfacing layer after processing shall not be less than 2 mm, and other combined forms can also be used. But no matter what kind of structure is adopted, it must be ensured that it will not loosen or fall off during use, and there will be no leakage at the joint.

3. When the gate valve is fully opened, the gate should be higher than the inner diameter of the channel.

4. The sealing surface of the valve seat and the sealing surface of the gate plate on the valve body must have sufficient width to ensure the complete fit after wear.

Hot Tags: flanged gate valve, China flanged gate valve manufacturers, suppliers, factory, 3 pvc gate valve, metal gate valve, 1 1 2 inch brass gate valve, check gate valve, air gate valve, gate valve stainless