All Types of Gate Valves

Classification by Design

Wedge Gate Valves

The most common type of valve.

The sealing element has a wedge shape and ensures tight shut-off of the flow.

Advantages:

• High tightness
• Reliability
• Suitable for high pressures

Disadvantages:

• Sensitive to temperature deformation
• Requires significant effort to open/close

Parallel Gate Valves

They use two parallel discs with a spacer element between them.

Advantages:

• Reduced risk of jamming
• Stable operation in high temperatures

Disadvantages:

• Lower tightness compared to wedge valves

Knife Gate Valves

Designed for viscous, contaminated, and fibrous media (slurry, pulp, wastewater).

The closing element is a thin plate that cuts through the medium.

Advantages:

• Operates in contaminated environments
• Simple design

Disadvantages:

• Not intended for high pressure
• Reduced sealing performance

Hose (Pinch) Gate Valves

Flow shut-off is achieved by compressing an elastic hose inside the body.

Used for aggressive or abrasive media.

Advantages:

• Excellent tightness
• No contact between medium and metal body

Disadvantages:

• Limited pressure range
• Periodic replacement of the hose required

Classification by Body Material

Cast Iron

Used in water supply and heating systems at low pressure.

Steel

Used in high-pressure pipelines, oil and gas industry.

Stainless Steel

Used in aggressive environments, food and chemical industries.

Non-ferrous Alloys (Bronze, Brass)

Used mainly in small diameters and utility networks.

Classification by Connection Type

• Flanged
• Welded
• Threaded
• Wafer type

Conclusion

The choice of a gate valve depends on operating conditions: pressure, temperature, medium type, and required tightness.

Correct selection ensures long service life, reliability, and safe pipeline operation.