Operational features of wedge gate valves

Wedge gate valves are designed for use as shut-off valves. During operation, these valves are usually either fully open or completely closed. When fully opened, the working medium flows through the valve in a straight line with very little resistance, so there is practically no pressure loss.

Classification

Wedge gate valves are divided depending on:

• Material. Products can be made from ferrous metals (steel, cast iron), or from non–ferrous (mainly copper) alloys.
• The method of receipt. For example, using cast iron as a starting material, cast wedge gate valves are obtained. At the same time, if necessary, to increase the tensile strength of the reinforcement, stamping technology is implemented for the manufacture of steel or brass valves. Combined versions are less common: welded or die-welded.
• Constructions. According to GOST 5762-2002, these details of pipe fittings are distinguished by the type of wedge (rigid, elastic, composite, hollow).
• Nomenclature of butt elements and parts. The main positions of choice are the type of seal, as well as the method of connecting the wedge valve to the main pipeline.
• The purpose of the attached part of the housing is with a full or incomplete passage.
• The permissible direction of movement of the working medium is straight or with reversal.

Each wedge valve size is calculated for a permissible pressure of at least 25 MPa, and the pressure limits depend on the conditional passage of the valve.

Application areas and advantages

Wedge gate valves work stably in pipelines where flow regulation or throttling is not used, or is used extremely rarely. They are recommended for systems with medium and low pressure, since high flow rates in partially open valves can cause erosion of disks and landing surfaces. At the same time, there are also high-speed wedge gate valves of the knife type, which are used in the pulp and paper industry.

Advantages of wedge gate valves:

• Good trip characteristics.
• The ability to change the flow direction.
• Minimum pressure loss.

Limitations when using

Wedge gate valves should not be used in high-speed flows, where the development of vibrations is possible. In addition, such types of fittings are characterized by:

• Slow opening/closing speeds.
• The requirements of a large installation space.
• Increased abrasion of moving parts.
• Sensitivity to temperature changes (the upper temperature limit should not exceed 1200C).

Taking into account the above factors, the standard sizes and designs of wedge valves are selected.