Butterfly valve

Best Suited Control:  Linear, Equal percentage

Recommended Uses:

1.  Fully open/closed or throttling services

2.  Frequent operation

3.  Minimal fluid trapping in line

Applications:  Liquids, gases, slurries, liquids with suspended solids

    Advantages:                  Disadvantages:

1.  Low cost and maint.          1.  High torque required for control

2.  High capacity               2.  Prone to cavitation at lower flows

3.  Good flow control

4.  Low pressure drop

    Ball valve

Best Suited Control: Quick opening, linear

Recommended Uses:

1.  Fully open/closed, limited-throttling

2.  Higher temperature fluids

Applications: Most liquids, high temperatures, slurries

    Advantage:                 Disadvantage:

1.  Low cost                 1.Poor throttling characteristics

2.  High capacity           2.Prone to cavitation

3.  Low leakage and maint.

4.  Tight sealing with low torque

    Gate valve

Best Suited Control:  Quick Opening

Recommended Uses:

1.  Fully open/closed, non-throttling

2.  Infrequent operation

3.  Minimal fluid trapping in line

Applications:  Oil, gas, air, slurries, heavy liquids, steam, non condensing gases,corrosive liquids

     Advantage:                   Disadvantage:

  1.  High capacity              1.Poor control

2.  Tight shutoff                2.Cavitate at low pressure drops

3.  Low cost                      3.Cannot be used for throttling

4.  Little resistance to flow

For more information,please refer to Valve Selection Guide to select the proper valve type.