Classification of Valves Used in Piping Systems

Valves exceed any other piping component. Estimates reveal that a substantial portion, approximately 8-10%, of the total capital expenditure of the chemical process industry is used for the procurement of valves. In terms of the number of units also. Hence, proper thought should be given for the selection of valves. The first step in the selection is to determine exactly what function the valve is expected to perform after it has been installed.

Valves are installed on equipment/ piping to perform any one of the below mentioned functions.

Classification of Valves:

  1. Based on functions:

Functions of valves
Functions of Valves

The design of the valves is done in such way as to perform any of the above functions. The type of valves used can be classified in the following categories.

Isolation valve

Regulation Valve

Non return valve

Special Purpose Valve

  1. Based on the end connections:

The valves can further be classified based on the end connections. End connection means

the arrangement or attachment of the valves to the equipment or to the piping. The types of

end connections are:

  • Screwed ends.
  • Socket weld ends
  • Flanged ends
  • Butt weld ends
  • Socketted ends
  • Wafer type ends
  1. Based on the materials of construction:

The valves could also be classified based on the materials of construction. There can be any number of combinations possible with the materials of construction. It is for the piping engineer to select the same in consultation with the process engineer to suit the process fluid.

The environment in which the valves are installed is also to be considered for selection of materials of construction. However, the most commonly available materials are:

  • Cast Iron
  • Bronze
  • Gun metal
  • Carbon Steel
  • Stainless Steel
  • Alloy Carbon Steel
  • Poly Propylene UHMW-PE,UHMW-HDPE etc
  • Special Alloys

Body could also be lined with elastomer so that process fluid will not be in contact with the metal.

The valve could also be classified based on the type of construction. Valve manufacturers offer endless varieties of construction. Based on the operation, valves can be broadly classified as operated valves and self-operated valves. Mainly the check valves are self-operated and all other types come under operated valves.

(Reference: “Selection and Application of Valve – Piping Handbook”)


  1. Nice blogs got from you expecting more knowledge will get in future.

  2. MANOJ kumar SINGH

    good knowledge

  3. good knowledge helpful for engineers and professionals

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