What is the Gate valve ? Purpose, Main Parts, Testing Methods, Advantages & Disadvantages :-

 

        It's the most common place form of valve utilized in any procedure plant. It is a linear movement valve used to begin or forestall fluid go with the drift. In service, those valves are both completely open and completely closed.

 A gate valve may be described as a form of valve that makes use of a gate or wedge-kind disk, and the disk actions perpendicular to go with the drift to begin or forestall the fluid go with the drift in piping.

 When the gate valve is completely open, the disk of a gate valve is completely eliminated from the go with the drift. Therefore in reality no resistance to go with the drift. Due to this, little or no stress drops whilst fluid passes via a gate valve. 360° floor touch is needed among the disk and seats whilst the valve is completely closed to obtain right sealing.

 Gate valves have to now no longer be used for law or throttling of go with the drift due to the fact correct manage isn't always possible. The excessive speed of the go with the drift with inside the in part open valve can also additionally reason erosion of the disc and seating surfaces and additionally creates vibration and noise.

Main Parts of Gate Valve:

These below parts are the most important parts of Gate valve.

        v Bonnet

        v Body

        v Wedge (Gate)

        v Body Seat

        v Stem

        v Back Seat

        v Gland Follower

        v Gland Flange

        v Stem Nut

        v Yoke Nut

Types of Gate Valves:

Generally we classify the gate valves depend upon follow factors,

1)   Based on Disk

Ø  Solid taper wedge

Ø  Flexible wedge

Ø  Split wedge or Parallel disks Valve

 

2)   Based on Body Bonnet Joint

Ø  Screwed Bonnet

Ø  Bolted-Bonnet

Ø  Welded-Bonnet

Ø  Pressure-Seal Bonnet

 

3)   Based on Stem movement

Ø  Rising Stem or OS & Y Type (Outside Stem and Screw Type)

Ø  Non-rising Stem type

TESTING:

Gate valves test by three parts.

                              i. Shell

                             ii. Seat

                            iii. Back Seat

Advantages and Disadvantages of Gate Valve:

The advantages of the gate valves may be said as follows:

• v  Good shutoff features.
• v  The frame production is simple, and the manufacturing manner is extra efficient.
• v  The period of the shape is instead short.
• v  The torque had to near and open the door is minimal.
• v  Gate valves are bidirectional and therefore they may be applied in directions.
• v  Low resistance to flow.
• v  Pressure loss via the valve is minimal.

 

The following negative aspects also can be taken into consideration for them:

• v  They can't be opened or closed quickly.
• v  Gate valves aren’t designed to manipulate the flow.
• v  Gate valves regularly have sealing surfaces, which makes processing, grinding, and preservation extra challenging.
• v  The abrasion and friction of the sealing floor boom even as establishing and shutting. Furthermore, it's far feasible to broaden abrasions while the temperature is high.
• v  In open conditions, they may be touchy to vibration.