Gate Valve

A gate valve, also known as a sluice valve, is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar, so gate valves are often used when a straight-line flow of fluid and minimum restriction is desired.

Gate valves are used to permit or prevent the flow of liquids, and are typically for on/off control rather than flow regulation. Because of their ability to cut through liquids, gate valves are often used in the petroleum industry.

Gate valves consists of three main parts: body, bonnet, and trim. The body is generally connected to other equipment by means of flanged, screwed or welded connections. The bonnet, which containing the moving parts, is attached to the body, usually with bolts, to permit maintenance.

Wedge gate valves act as reliable devices to connect and close the fluid in pipeline of in oil & gas, petrochemical refinery, coal-fired power generation and water treatment. It comes with two types of solid wedge and flexible.

wedge gate valves are not piggable because of the void that is left in the bottom of the valve body when the valve is open. These valves do not have a bore through the gate itself; instead, the gate retracts into the valve body when open, which saves height space.

Wedge gate valves are commonly supplied with solid wedge up to 2” size and with flexible wedge for larger sizes.

Flexible Wedge Gate Valves

Flexible Wedge Gate Valves design consists of two independent and flexible wedge halves, that allow a relative movement to accommodate changes in the body seat angles.

[caption id="attachment_2732" align="alignnone" width="434"] Flexible Wedge[/caption]

Features and benefits

1. Flexible wedge is ground and lapped to a mirror finish and tightly guided to prevent dragging and seat damage.  Wedge is hard faced with 13Cr, SS 316, Stellite 6, Monel or CoCr alloy.
2. Seat face is hard faced with 13Cr, SS 316, Stellite 6, Monel or CoCr alloy;  and ground and lapped to a mirror finish.
3. Body and bonnet joint accurately machined.
4. Body and bonnet castings are precision machined.
5. One-piece bonnet for better alignment and fewer parts for Class 150 up to NPS 16 (DN 400).
6. Rotating stem nut is Austenitic ductile iron Gr. D-2C renewable in line (as shown).
7. Design to ASME B16.34, API 600

Solid Wedge Gate Valves

Solid wedge is designed in one-piece model while flexible wedge offers a wedge shape for both seats.

[caption id="attachment_2733" align="alignnone" width="397"] Solid Wedge[/caption]

Features and benefits

1. Designed for 2”and below; bigger sizes are available upon request.
2. The solid wedge is more reliable for durable operation compared to flexible wedge, while the cost is higher than flexible wedge gate valve.
3. Design to API 602 for sizes 2" and below; ASME B16.34, API 600 for 2" and bigger