Gate Valve

This Cast Steel Gate valve features a bolted bonnet with Class 150 to Class 1500 flanges in sizes 2 to 30”. The one piece flexible wedge with a tapered H shape is fully guided and suitable for steam and other high temperature service. The yoke sleeve is designed to allow for disassembly without disconnecting the bonnet and stem. Standard body materials are A216-WCB, A217-WC6 or A351-CF8. Depending on service conditions, other material options are available for valve and trim.

Sizes: 2” – 30”

Larger sizes are available upon request

ANSI Class: 150 – 1500

Features: API 600/603, Testing to API 598, Bolted Bonnet/Pressure Seal Bonnet, Outside Screw & Yoke, Flexible Wedge, Fully Guided Wedge, Rising Stem, Standard/NACE

Body: Carbon, Alloy or Stainless Steel (WCB, LCC, WC6, C5, C12, CF8)

Trim: Trim 5, Trim 8, Trim 16

End Connections: Raised Face (RF), Flat Face (FF)

Also available in RTJ and Butt Weld

*Additional sizes and materials available upon request. Availability is dependent on market demands

FUNCTION

Gate valve is characterized by a sliding wedge which is moved by actuator perpendicular to the flow direction. There are a variety of valve sizes and types. The valve is used primarily as a stop valve to open or close fully. Normally it works for slurries, viscous fluid, etc. but not for throttling. The gate valve usually has a minimum pressure drop in full open and a tight seal in full close, and therefore there is little possibility that contaminants may enter the valve.

BODY AND BONNET

The body and bonnet is designed to achieve most uniform distribution of stress on all sides and minimum turbulence and resistance to flow. The bonnet on valve is equipped with back seat ring up to 12" for Class 150 & 300 and up to 10" for Class 600 or higher. The yoke is integrated with bonnet.

BODY AND BONNET JOINT

Body-bonnet joint of gate valve is machined as follows:

Class 150 ................................... Plain faced

Class 300 and higher class ........ Male and female

We can supply any kinds of gasket as required by customer

WEDGE

The valve is normally supplied with a one-piece flexible wedge of which the cross section is a tapered H shape.

All wedges are fully guided. The flexible wedge is cast or machined with circumferential grooves to allow the seating faces to move independently and adjust the movement of body seat.

It is used where the line load or thermal expansion of system may distort the seating face of valve, and especially useful to prevent sticking that may happen in case the valve is closed at a hot temperature and opened at a cold temperature.

Ideally the wedge is suitable for steam and other high temperature service.

SEAT RING

The stem connection to the wedge shall have an integrated tee head (without welding)and is rectified in the packing area to ensure a long life and perfect tightness. Through experiments, we have calculated and checked the connections between stem and wedge not to disengage the stem from wedge while gate valve is working.

The strength of stem and wedge connections is stronger than that of stem alone at the root of thread.

STEM

The packing size is designed to secure maximum tightness along the stem, and the standard packing is a non-asbestos type. We can supply any kinds of packing as required by customer.