Gate Valve

Ball Valve

1. Sizes

Larger diameters

A gate valve is mainly used in pipes with a larger diameter. This is because it is simpler in construction than the other options you have for shutting down and starting a large flow (butterfly valves).

Gate valves are not used very often below DN50 (2")

Small and medium diameters

In the smaller diameters, a ball valve is usually preferred above a gate valve because a ball valve is simpler and therefore cheaper than a gate valve. 

Ball valves are not used very often above DN200 (8 ").

2. Pricing

Higher

Because a gate valve is somewhat more advanced than a ball valve and contains more parts, a gate valve is generally more expensive than a ball valve with comparable specifications.

Lower

Ball valves come in many different designs and generally cost less than a gate valve.

3. Movement

Vertical

A gate valve moves a solid disk up and down to open or close the orifice.

Horizontal

A ball valve moves a ball (orifice) with a bore in it to open or close the valve.

Hollowed ball acts as a disc that allows the flow.

4. Manual operation

Round knob 

The round knob of gate valve is used to control flow of water when turned, this ups or down internal gate to start or stop the flow of water.

Stem

Ball valve contains a stem and a ball which turn horizontally. That’s why ball valve is also called rotational valve.

5. Shut-down speed

Slow

Gate valve is a bit slow for shutting down the immediate flow and they are often used in high pressure applications.

Immediate

Ball valve is best suitable where immediate shut off the flow is required. They are used in low pressure application.

6. Application usage

Gate valves are used in non critical application where high quality sealing is not required.

Gate valve comes with a sealing surface dividing the gate and the seats, gate valves are used when a straight line flow with minimum curb is required.

Ball valves are used in application where small diameter or low pressure is required,and prevention of leakage is priority, that can be up to DN 300 or 12 inch diameter pipe.

Ball valves are quarter turn valve, they use a hollow ball which is perforated and pivoted to control the flow. Valve opens when hole of ball is in line with flow and closes when pivoted to 90 degree.

7. Materials

Due to the more advanced shapes and parts, gate valves are mainly available in different metals such as stainless steel, cast iron, cast steel, bronze and copper.
Gate valves are also available made of PVC, PP or HDPE plastics, but the choice is limited.

Also various plastics

Ball valves are somewhat simpler in design than gate valves. This makes them extremely suitable for manufacturing from plastics.

Ball valves are available in many versions and in many different types of plastic.