Basics of Gate Valves

The Gate valve is a linear actuating  valve used as flow isolater in a fluid pipeline.  As the name says the gate valve, a flat  circular or rectangular plate acts as a ‘gate’ in a pipeline. We call this plate as disc ,gate or wedge.

When the valve actuates down the gate slice the fluid  to total shut off .

Basics of Gate Valves

The disc can moved up fully into the upper portion of the body and results no hindrance to the fluid flow cross section area.  This  makes the valve  full open with very less pressure drop.

Gate valves (also known as knife valves or slide valves) are linear motion valves in which a flat closure element slides into the flow stream to provide shut-off. They are one of the most common valves used.

Gate valves use linear type of stem motion for opening and closing of a valve. These valves use parallel or wedge shaped discs as closure members that provide tight sealing.

Best Suited Control: Quick Opening

Recommended Uses:

• Fully open/closed, non-throttling

• Infrequent operation

• Minimal fluid trapping in line

Advantages :

• High capacity

• Tight shutoff

• Low cost

• Little resistance to flow

• Ability to cut through slurries, scale and surface build-ups

• Provide unobstructed  flow paths that not only provide  high flow capacity  (Cv), but even allows slurry, large objects, rocks and items routinely found in mining processes to safely pass through the valve.

Disadvantages :

• Poor control

• Cavitate at low pressure drops

• Cannot be used for throttling

• Relatively low  pressure  limitation  –  general  pressure  limitations  are  150  psi  at maximum.

Applications :

• Suitable for oil, gas, air, heavy liquids, steam, non-condensing gases, abrasive and corrosive liquids

• Sizes available  range  from  standard  cast  configurations  as small  as 2″ to special fabricated valves exceeding 100″.

• Standard cast configurations  have ASME 125/150 bolting patterns and are rated at 150 psi.

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