Valves

A valve is a device that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways.

The simplest structure of valve and its components are shown in diagram

 

Valves may also be classified by how they are actuated:

• Hydraulic
• Pneumatic
• Manual
• Solenoid
• Motor

Regular examples of Valves are follows:

1. Ball Valve

2. Gate valve

3. Check valve (NRV)

4. Butterfly  Valve

5. Globe Valve

6. Knife Gate Valve

7. Needle Valve

8. Foot Valve

9. Diaphragm Valve

10. Solenoid Valve

 

The Symbol for valves used in line diagram are as follows

 

ISI Mark

ISI mark is a certification mark for industrial products in India. The mark certifies that a product conforms to the Indian Standard,mentioned as IS:xxxx on top of the mark, developed by the Bureau of Indian Standards (BIS), the national standards body of India. The ISI mark is by far the most recognized certification mark in the Indian subcontinent. The name ISI is an abbreviation of Indian Standards Institute, the former name of the Bureau of Indian Standards. The ISI mark is mandatory for certain products to be sold in India, like many of the electrical appliances viz; switches, electric motors, wiring cables, heaters, kitchen appliances etc., and other products like portland cement, LPG valves, LPG cylinders, automotive tyres etc. But in the case of most other products it is voluntary