Valve Types with Their Advantages and Disadvantages

A butterfly valve is a quarter-turn valve used to regulate the passage of fluids through a pipe. Some level of control is also provided to the fluid. The design is such that complete flow is provided but with a set amount of efficiency. You cannot get positive shut-off from butterfly valves. But now it&#;s possible to build butterfly valves with tight closure thanks to high-temperature ratings and the latest polymers.

Check now

Several components of a butterfly valve include a metallic disc or butterfly disc, an outer body/casing, an actuator, and a positioning plate. A strong seal is made due to the packing. This seal surrounds the stem and protects the stem. The disc is mounted on a rod and stops fluid passing when the valve is closed.

The disc moves depending on the opening or closing of the valve. When the disc rotates perpendicular, the valve is entirely open, and a large amount of fluid can pass through the pipe. A seat is also fixed on the body. This seat gives a proper seal to the body. Most manufacturers provide an additional seal in case the seat gets damaged.

Butterfly Valves Advantages

Butterfly valves are widely used for several reasons. Some advantages of check valves are as follows:

• Butterfly valves are lightweight with a wafer-form body. The low weight and compact size make them favourable for use in many applications.
• Butterfly valves are relatively cheaper than other valves. This may be because of the low weight and that a small number of components are used in their construction.
• The installation costs are low.
• The design is not complicated. A small number of parts are used in the construction of butterfly valves.
• It is reasonably convenient and easy to repair butterfly valves. So we can say they are maintenance-friendly.
• Butterfly valves can transfer mud with a little fluid deposit in the outlet of the pipe.

Butterfly Valves Disadvantages

There are a few disadvantages of using butterfly valves. They are discussed below:

• A part of the butterfly disc is always facing the flow even if it&#;s completely open. So there&#;s still a pressure switch over the valve no matter what the setting is.
• The sealing is not as good as other valves.
• When butterfly valves are used, throttling is limited to low-pressure drop systems.
• Sometimes, the choked flow may occur when using a butterfly valve.

The suitability of a valve for a specific application is defined by the materials used in relation to the transported fluid as well as its mechanical design. Here is Indelac Valve Selection Guide.

Valve Selection Table

The tables below can be used as a valve selection guide taking into consideration the state of material, its nature and the function of the valve.

Conveyed Fluid

Nature of Fluid

Valve Function

Type of Disc

Liquid Neutral (Water, Oil, etc) On/Off Gate Rotary ball Plug Diaphragm Butterfly Plug gate Control valve, modulating Globe Butterfly Plug gate Diaphragm Needle Corrosive (Acid, alkaline etc.) On/Off Gate Plug gate Rotary ball Plug Diaphragm Butterfly Control valve, modulating Globe Diaphragm Butterfly Plug gate Hygienic (Food, beverages, drugs etc) On/Off Butterfly Diaphragm Control valve, modulating Butterfly Diaphragm Squeeze Pinch Slurry On/Off Rotary ball Butterfly Diaphragm Plug Pinch Squeeze Control valve, modulating Butterfly Diaphragm Squeeze Pinch Gate Fibrous Suspensions On/Off, Control valve, modulating Gate Diaphragm Squeeze Pinch

 

Conveyed Fluid

Nature of Fluid

Valve Function

Type of Disc

Gas Neutral (Air, Steam etc) On/Off Gate Globe Rotary ball Plug Diaphragm Control valve, modulating Globe Needle Butterfly Diaphragm Gate Corrosive (Acid vapors, chlorine etc.) On/Off Butterfly Rotary ball Diaphragm Plug Control valve, modulating Butterfly Globe Needle Diaphragm Vacuum On/Off Gate Globe Rotary ball Butterfly

 

Conveyed Fluid

Nature of Fluid

Valve Function

Type of Disc

Solids Abrasive Powder (Silica, etc) On/Off, Control valve, modulating Pinch Squeeze Spiral sock Lubricating powder (graphite, talcum, etc) On/Off, Control valve, modulating Pinch Gate Spiral sock Squeeze

 

Valve Type Pros and Cons

Because everything is easier to understand with a table, here is another one summarizing pros and cons for the most common valves.

Valve

Advantages

Disadvantages

Butterfly

Quarter turn

Difficult to clean

Open port

Difficulty with slurries

Used with chemical or corrosive media

Throttling limited to low differential pressure

Compact, lightweight design

Potential for cavitation and choke

Available in large sizes

Unguided disc movement is affected by flow turbulence

Low pressure drop and high-pressure recovery

 

High coefficient of flow

Ball

Superior ease of operation

 Poor throttling characteristics

Maintains and regulates high volume,

 Difficult to clean, leads to contamination

high pressure, and high temp flow

 

Rugged construction and long service life

Low purchase and maintenance cost

Able to function without side loads

Permits inspection and repair of seats and seals without removing the valves' body from the line

kairuite contains other products and information you need, so please check it out.

Related articles:
IBC Valves | Bulk & Wholesale Available | BascoUSA.com

Does not require lubrication

Diaphragm

Extremely clean

Can only be used in moderate temperature (-60 to 450ºF)

Leak proof seal

Can only be used in moderate pressures (approximately 300psi)

Tight shut-off

Cannot be used in multi-turn operations

Easy maintenance

No industry standard face-to-face dimensions

Repairs can be made without  interrupting pipe line

The body must be made of corrosive resistant material

Reduce leakage to the environment

 

Gate

Available in large sizes

Low pressure limitations

Can be used with slurries and viscous liquids

Slow open and close time

Used as a shut off valve

Erosion of the seat and disk can occur

Easy to maintain and disassemble

Poor throttling characteristics

Inexpensive

Difficult to repair

Inherently fire-safe (when used with a metal sheet)

Should not be used in sanitary applications

Bidirectional

 

Globe

Can be fast-acting

High head loss

Precise control

Large opening for disk assembly

Can be used in high-pressure systems

Heavier than other valves

 

Cantilevered mounting of the disk to the stem

Low coefficient of flow

Not good for clean or sterile applications

Pinch

Very Clean

Cannot be used in high temperature applications

Excellent drainage

Cannot be used in high pressure applications

Minimal turbulence

Cannot be used with gas media

Low airborne contaminants

 

Low maintenance

Low weight

Can be used in explosion-proof lines

Inexpensive

Once the right valve has been selected, it is time to select the right actuator! See link below to Indelac Actuator Selection Guide:

Want more information on control valves? Feel free to contact us.