Type Of Valve

Type of Valve

Valve is a mechanical device which is used to isolate, regulate and control the fluid flow.

Like: liquids, gases and slurries.

 

 

There Are A Many Type Of Valve

• Gate valve
• Globe valve
• Butterfly valve
• NRV (non return valve) / check valve
• PRV/PSV (pressure relief valve / pressure safety valve)
• Ball valve
• Needle valve
• Pinch valve 
• Plug valve
• Control valve

  

Gate valve

 

Gate valve is most common type of valve in any process plant.

It is linear motion valve use to start and stop the flow. This valve are fully open and fully close position.

Gate valve is also known as isolation valve.

Ex. water, air, steam, hydrocarbon.

 

Globe valve

 

 

Globe valve use for flow regulate as per need a flow control.

Globe valve are use in system when flow control is require and leak tightness is require.

Gate Valve is provide better shut-off as compare to gate valve.

It is costly than gate valve.

 

Type of globe valve

 

• Z-Shape Globe Valve
• Angle Shape Globe Valve
• Y-Shape Globe Valve

Z-Shape Globe Valve :

This valve is most common valve.

Fluid flow has in straight type.

This valve use for no matter pressure drop on effect.

A “Z shape” globe valve is not a standard type of globe valve their use in industrial or plumbing applications.

 

Angle Shape Globe Valve

An angle globe valve, sometimes referred to simply as an angle valve, is a type of globe valve designed with an angled body configuration.

Here are the main features and components of an angle globe valve:

Body

The body of an angle globe valve is made of materials such as cast iron, stainless steel, or bronze.

 

Bonnet

Similar to other globe valves, the bonnet of an angle globe valve is the removable portion of the valve body that provides access to the internal components, such as the valve stem and disc.

 

Valve stem

The valve stem is a rod that connects the handwheel or actuator to the valve disc.

Rotating the handwheel or activating the actuator moves the valve stem, which in turn opens or closes the valve.

 

Valve disc

The valve disc, also known as the plug, is the component that controls the flow of fluid through the valve. When the valve is open, the disc lifts away from the valve seat, allowing fluid to pass through. When the valve is closed, stop the flow of fluid.

 

Valve seat

The valve seat is prevent the flow of fluid when valve is closed. It ensures a tight seal to prevent leakage.

 

Inlet and Outlet pots

The angled configuration of the valve body results in an inlet and outlet port that are oriented at 90 degrees to each other. This design allows for easier installation in piping systems where space constraints or specific piping configurations exist.

Handwheel and actuator :Angle globe valves can be manually operated using a handwheel or automated using an actuator. The handwheel allows for manual opening and closing of the valve, while an actuator enables remote or automatic operation.

Angle globe valves are commonly used in applications where space limitations or specific piping configurations require an angled approach to the flow control. They are often found in HVAC systems, water distribution systems, steam systems, and various industrial processes where precise flow control is necessary.

 

Y-Shape Globe Valve

This valve is suitable for high pressure and critical service.

Body

The main structure of the valve, usually made of materials such as cast iron, stainless steel, or bronze. The body houses the internal components of the valve and provides the connection points for piping.

 

Bonnet

The bonnet is the top portion of the valve body, which is removable to provide access to the internal components such as the valve stem and disc.

 

Valve Stem

A rod that connects the handwheel or actuator to the valve disc. Turning the handwheel or activating the actuator moves the valve stem, which in turn moves the disc to open or close the valve.

 

Valve Disc (Plug)

The valve disc, also known as the plug, is the component that regulates the flow of fluid through the valve. When the valve is open, the disc lifts away from the valve seat, allowing fluid to pass through. When the valve is closed, the disc makes contact with the seat, preventing the flow of fluid.

 

Valve Seat

The valve seat is the sealing surface where the valve disc makes contact to stop the flow of fluid when the valve is closed. It ensures a tight seal to prevent leakage.

 

Inlet and Outlets

The Y-shaped configuration of the valve body typically includes one inlet and two outlets. The fluid enters through the inlet and can be directed to either of the two outlets depending on the position of the valve disc.

 

Handwheel or Actuator

Y-shaped globe valves can be manually operated using a handwheel or automated using an actuator. The handwheel allows users to manually open or close the valve by turning it, while an actuator can be used for remote or automatic operation.

Y-shaped globe valves are commonly used in applications where throttling or fine control of the flow rate is required, similar to T-shaped globe valves. They are suitable for various industries such as oil and gas, petrochemical, chemical, power generation, and water treatment. Their design allows for effective flow control and reliable sealing performance.

 

 

Globe valve Disc type

• Conventional disc (ball disc)
• Composite disc
• Plug disc

 

Advantage

Better shut-off as compared to gate valve.

Good for frequent operation as no fear of wear of seat and disc.

Easy to repair as seat and disc.

Fast operate compare to gate valve due to shorter stroke length.

 

Disadvantage

High head loss from or more right angle turn of flowing fluid within the valve body.

Obstruction and discontinuities, pulsation and impacts can damage internal from part.

 

 

Butterfly Valve

 

 

Butterfly valve is a type of quarter turn valve.

Quarter turn means 1/4 ( full turn means 90 degree)

A quarter turn valve can open or close whenever the handle is turn 90 degree.

The handle can be turned manually or pneumatically . the function of these valve is to control the flow of liquid through a suction pipe.

 

There are Two Of Type Butterfly Valve

There are two types of valves: the ball valve and the gate valve.

There are two types of valves: the ball valve and the gate valve.

There are two types of valves: the ball valve and the gate valve.

There are two types of valves: the ball valve and the gate valve. The ball valve is a commonly used valve that utilizes a spherical disc to control the flow of fluids. It offers excellent shut-off capability and low friction loss. On the other hand, the gate valve is a linear motion valve that uses a wedge-shaped gate to control the flow. It is often preferred for applications where a tight seal is required.

• Manually
• Pneumatically

 

Application of butterfly valve 

Butterfly valve are mainly used in waste treatment system and in other industrial application. They are extremely durable and need minimal maintenance.

Pressure rating shut-off at temperature up to maximum limit of the seat material.

Butterfly valve size and pressure limits:

2′ – 12″ 200 psi

14″ – 48″ 150 psi

 

Butterfly valve parts

 

Resilient seat

Body

Packing

Stem

Actuator

Disc

 

The most important one is the metal disc. The metal disc is the commonly referred as the butterfly.

The butterfly is mounted on road and when the valve is closed it blocks passage of fluid.

When valve is full open the metal disc or butterfly moves a quarter turn. The passage way is unrestricted allowing fluid to pass.

 

NRV (non return valve)/ check valve

 

 

A non-return valve, also known as a check valve or one-way valve, is a mechanical device used in piping systems to allow fluid to flow in only one direction.

It prevents reverse flow or backflow of fluids, ensuring that fluids flow in the intended direction and preventing contamination of upstream systems.

Backflow occurs when the direction of flow in a piping system reverses, potentially causing contamination or damage to equipment. Non-return valves prevent backflow by automatically closing when the flow direction reverses.

Non-return valves are designed to provide minimal resistance to flow when open, thereby minimizing pressure drop across the valve.

Non-return valves are used in a wide range of industries and applications, including water supply systems, wastewater treatment plants, irrigation systems, chemical processing plants, oil and gas pipelines.

Non-return valves are available in various materials such as brass, stainless steel, PVC, and cast iron, among others.

 

Type Of NRV ( check valve)

 

 

 

• swing check valves
• lift check valves
• ball check valves

 

Swing Check Valves

Design

A swing check valve consists of a disc or flap that swings open and closed on a hinge or pivot point within the valve body. The disc or flap is typically made of the same material as the valve body and may have a sealing surface to ensure a tight shut-off when the valve is closed.

Flow Control

When the fluid flows in the desired direction, it pushes the disc or flap away from its seat, allowing the fluid to pass through the valve. The swinging motion of the disc or flap allows for unobstructed flow.

Prevention of Backflow

If the flow direction attempts to reverse, the disc or flap is forced against its seat by the pressure of the fluid, creating a seal that prevents backflow. This action stops the fluid from flowing backward and maintains the integrity of the system.

Low Resistance

Swing check valves typically have low resistance to flow when open, which helps to minimize pressure drop across the valve and maintain efficient flow through the pipeline.

Versatility

Swing check valves are versatile and can be used in a wide range of applications and industries, including water distribution systems, wastewater treatment plants, irrigation systems, chemical processing plants, and HVAC systems.

Installation Orientation

Swing check valves can be installed in horizontal pipelines or vertical pipelines, depending on the specific requirements of the application. The swing mechanism allows the valve to operate effectively in various orientations.

Maintenance

Swing check valves are generally simple in design and require minimal maintenance. However, periodic inspection and cleaning may be necessary to ensure proper operation and prevent any obstructions that could affect valve performance.

 

Lift Check Valves

Design

A lift check valve consists of a disc or piston that moves vertically within the valve body. When fluid flows in the desired direction, the pressure of the fluid lifts the disc or piston, allowing the fluid to pass through the valve.

Flow Control

Lift check valves control the flow of fluid by moving the disc or piston in response to changes in pressure. When the pressure of the fluid is greater on the inlet side than the outlet side, the disc or piston lifts, allowing flow. When the pressure equalizes or reverses, the disc or piston seats against the valve body, preventing backflow.

Prevention of Backflow

Lift check valves prevent backflow by creating a seal when the disc or piston seats against the valve body. This seal prevents fluid from flowing in the opposite direction and maintains the integrity of the system.

Low Resistance

Lift check valves typically have low resistance to flow when open, which helps to minimize pressure drop across the valve and maintain efficient flow through the pipeline.

Versatility

Lift check valves are versatile and can be used in a wide range of applications and industries, including water distribution systems, wastewater treatment plants, irrigation systems, chemical processing plants, and HVAC systems

Installation Orientation

Lift check valves are designed to be installed in vertical pipelines. The vertical orientation allows the disc or piston to move freely in response to changes in pressure and ensure proper operation of the valve.

Maintenance

Lift check valves are generally simple in design and require minimal maintenance. However, periodic inspection and cleaning may be necessary to ensure proper operation and prevent any obstructions that could affect valve performance.

 

Ball Check Valves

Design

A ball check valve consists of a spherical or ball-shaped mechanism inside a valve body. The ball is typically made of a resilient material such as rubber, plastic, or metal, depending on the application.

Flow Control

When the fluid flows in the desired direction, the pressure of the fluid pushes the ball away from its seat, allowing the fluid to pass through the valve. The ball moves freely within the valve body to accommodate the flow.

Prevention of Backflow

If the flow direction attempts to reverse, the ball is forced against the seat by the pressure of the fluid, creating a seal that prevents backflow. This action stops the fluid from flowing backward and maintains the integrity of the system.

Low Resistance

Ball check valves typically have low resistance to flow when open, which helps to minimize pressure drop across the valve and maintain efficient flow through the pipeline.

Versatility

Ball check valves are versatile and can be used in a wide range of applications and industries, including water distribution systems, wastewater treatment plants, irrigation systems, chemical processing plants, and marine applications.

Size and Configuration

all check valves are available in various sizes and configurations to suit different pipe diameters and flow rates. They can be installed in horizontal, vertical, or inclined pipelines, depending on the specific requirements of the application.

Maintenance

Ball check valves are generally simple in design and require minimal maintenance. However, periodic inspection and cleaning may be necessary to ensure proper operation and prevent any obstructions that could affect valve performance.

 

PRV/PSV (pressure relief valve/Pressure safety valve)

 

 

PRV is protection of life, property and environment during over pressure event in a pressurized vessel or equipment.

An over pressure event refer to any condition which would cause pressure in a vessel or system to increase beyond thew specific design pressure or maximum allowable working pressure.

PRV designed to open and relief excess pressure from vessel or equipment and re-close and prevent the further releases of fluid after normal conditions have been restored.

PRV is a safety device and in many causes the last line of defense.

PRV is capable to operate at all times and under circumstances.

PRV should have to be operate for one purpose only : over pressure

 

Reason for excess pressure in vessel

There are number of reactions -Why the pressure in a vessel or equipment can exceed a predetermined limit ?

Blocked outlet

Exposure to extend fire often referred to as fire case

Thermal expansion of fluid

Abnormal process condition ( Reaction)

Cooling system failure

Heat exchanger tube rupture

Pipe work component failure 

Control valve failure

 

 

Type of PRV

 

 

• Spring loaded
• Pilot loaded
• Dead Weight loaded

 

Ball valve

 

Ball valve is quarter turn rotary motion valve.

This valve use in low pressure utility.

Ball valve lighter and smaller than gate valve.

The ball valve is one of the quickest valve because if only needs quarter turn to open.

 

Needle valve

 

A needle valve is a type of valve used to control the flow rate of fluid in a pipeline with precision.

It is designed with a slender, tapered needle-like plunger that fits into a matching seat.

The fine adjustment possible with the needle valve makes it suitable for applications requiring accurate flow control.

The needle valve size 1/4 inch – 1 inch.

 

Needle valve types

 

• Straight needle valve : straight needle valve has an inlet and outlet a straight line 180 degree allowing for straight flow through valve. 
• Angle needle valve : Angle needle valve has an inlet and outlet at 90 degree from one to another.
• Multiport needle valve : A multiport needle valve has normally more than two port and it can have 3, 4 and 5 way control.

 

Pinch valve

 

Pinch valve is a linear motion valve.

Rubber tube called pinch valve.

ON/OFF : starts or stop flow within a system.

Flow control : Regulate the flow

Used to control solid material like slurry.

 

Plug valve

 

 Plug valve is quarter turn rotary motion valve.

Why this valve called plug valve – Because this valve in side plug type disc

This valve worked on/off valve.

This valve mechanism is very simple.

Maintenance work is easy for repair.

Low pressure drop.

Reliable and tight seal capacity.

Fast acting to open close as it only needs.

Use in temperature, vacuum and high pressure.

 

 

Control valve

 

Control valve use to manage and direct the flow of fluid by varying the size of the flow passage.

Control valve provide the direct control of flow, temperature, pressure and level.

Most frequently used in process control sector.

Used the counteract the load disturbance and maintain the regulated process variable as close to the intended set point.

Help in stable run of plant operations.

Decreases the manpower requirement.

 

Control valve parts

 

 

 

Actuator

Transducer

Positioner

Valve

 

Transducer receiver a signal from DCS/PLC.

AS per input of 4-20 mA transducer converts it to pressure signal of 0.2-1 Kg/Cm2

Actuator is the device connected to the valve through the valve stem that provide the force required to move the valve.

 

Type of control valve

 

(i) Pressure drop profile 

• Low recovery valve
• High recovery valve

 

(ii) Movement profile of controlling element

• Rotary valve
• Sliding valve

 

(iii) Medium of actuation

• Manual valve
• Pneumatic valve
• Hydraulic valve
• Electric valve

 

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