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Ball valve selection guide

A ball valve is a globe valve that uses a rotating ball with a hole to control the flow of a liquid or gas. The rotating ball is rotated a quarter turn (90°) about its axis to allow or stop flow through the valve. These valves are prized for their longer life and reliable sealing performance. When selecting a ball valve, there are many options on the market. However, a wide range of operating ranges, connection types, loop functions, housing materials, and many other criteria complicate the valve selection process.

1. Type of operation

Ball valves can be manually, electrically, or pneumatically operated. The different actuation methods have their advantages and disadvantages.

Manual: If you have a low budget, do not have electricity/compressed air available for installation, or do not need automation, you should choose a manual ball valve. Manual ball valves should not be used if the ball valve needs to be opened and closed frequently or if the system needs to be automated.

Automatic: Deciding between electric and pneumatic ball valves can be difficult. It usually comes down to what is available at the installation site (electricity or compressed air) and the required torque (pneumatic ball valves have higher torque, so pneumatic is used for larger valves). Electric ball valves have a higher initial cost but lower operating costs than pneumatic ball valves.

2. Circuit Function

Depending on the number of ports, ball valves may have 2-way, 3-way, 4-way, or 5-way circuit functions.

2-way ball valves are the most common type of ball valve. These valves provide a straight flow path from input to output.

3-way ball valves: Three-way ball valves have three ports available with either L or Tholes. The L and T designations refer to the design of the bore, which will determine the direction of flow. Three-way ball valves with T or L ports allow mixing, dispensing, or changing the flow direction for different applications. This makes the valve suitable for heating or cooling applications with water, chemicals, and oil.

4-way ball valves: 4-way ball valves are not as standard as 2-way and 3-way ball valves, but it is essential to understand their variations. Four-way ball valves are typically available in four variants: L-port, T-port, X-port (LL-port), and straight.

5-Way Ball Valves: Vertical double L-port valves are available; these five-way valves are rare.

3. Housing Materials

The valve's housing material should be compatible with the fluid media used in the application. Standard materials and their characteristics are


Suitable for neutral and noncorrosive media.

Brass is versatile, durable, and resistant to high temperatures.

Not suitable for saltwater (seawater), distilled water, acids, and chlorides.


Suitable for corrosive media such as seawater, most acids and bases, salt solutions, and organic solvents.

Not resistant to aromatic and chlorinated hydrocarbons.

Lower temperature and pressure range than brass and stainless steel.

Stainless steel

Excellent general chemical resistance to almost any medium.

Very wear-resistant, resistant to high temperatures and pressures.

Not suitable for use with hydrochloric acid, chlorides, bromine, and bleaching agents. On the other hand, swimming pool water has a low chlorides concentration, so that stainless steel can be used here.

4. Seals

Ball valves have two seals. The seat ring is located around the ball at the inlet and outlet, and the O-ring seals the valve stem. Typically, the seal ring is made of PTFE. For both seals, the seal material should be compatible with the fluid medium used in the application. Standard materials and their characteristics are

Ethylene Propylene Diene (EPDM)

EPDM is well suited for low water concentrations, steam, ketones, alcohols, brake fluid, acids/alkalis.

Excellent resistance to weather effects and ozone.

The typical operating temperature range is -10° to 130°C.

FKM (Fluorinated Rubber)

FKM has excellent overall chemical resistance to oils and solvents (e.g., aliphatic, aromatic halogenated hydrocarbons, acids, animal and vegetable oils).

The typical operating temperature range is -10°C to 120°C.

It has good mechanical properties, is resistant to compression, and is suitable for high temperatures (not suitable for hot water/steam).

Nitrile Rubber

NBR has good resistance to compression, tearing, and abrasion.

Compatible with oils, solvents, and alcohols.

Typical operating temperatures up to 80°C.

Polytetrafluoroethylene (Teflon)

PTFE is resistant to virtually all fluids.

PTFE is relatively hard; this makes it suitable for higher working pressures and temperatures.

The typical operating temperature range is -30°C to 180°C.


POM is suitable for high-pressure and low-temperature applications.

CSM (Hypalon)

Hypalon is known for its resistance to chemicals, extreme temperatures, and UV light.

5. Connection Types and Sizes

There are different sizes and types of ball valve connections available to connect them to the system. Some common ones are

Standard/Threaded Ball Valves: Threaded connections are the most common connection type used for a wide range of temperature and pressure applications.

Flanged Ball Valves: These have flanged connections connecting the ports to the piping system. These valves are typically used in larger pipe sizes. Choosing a flanged ball valve requires consideration of the pressure rating and flange compression rating, which indicates the maximum pressure it can withstand.

Welded Ball Valves: The ball valve is welded directly to the pipeline in a welded connection. This type of connection is suitable for applications where zero leakage is required.

Proper union ball valves: These valves have a solvent socket connection at each port. The center section of the valve can be easily disassembled and removed when the valve is installed. This is suitable for quick repairs and maintenance in flow systems.

6. Flow Coefficient (Kv)

The flow coefficient, or Kv value, is expressed as the flow rate in m3/h of water at 20°C at a pressure drop of 1 bar. 

7. Pressure

Ensure the ball valve can withstand the minimum and maximum pressures in the system. The housing material helps determine the pressure range of the ball valve. Stainless steel usually has the highest rating for maximum pressure, followed by brass and then PVC housings. Be sure to check your ball valve datasheet to confirm the proper pressure range.

8. Temperature

Ensure the valve material can withstand the maximum and minimum temperature requirements of your operation. The housing and seal materials typically determine the temperature range of the ball valve. Typical ranges are listed below but check the ball valve datasheet to confirm.

Brass ball valves: -20°C to 60°C (-4°F to 140°F)

PVC ball valves: -10°C to 60°C (14°F to 140°F)

Stainless steel ball valves: -40°C to 220°C (-40°F to 428°F)

9. Approvals and Standards

Depending on the application, ball valves may need to be manufactured to specific standards or approved by regulatory agencies for use in certain applications, such as potable water or gas.

Potable water: WRAS, KIWA, or DVGW approval

Gases: DVGW or EN-331 certification.

ATEX: The ATEX regulations are two EU directives detailing minimum safety requirements for workplaces and equipment used in explosive atmospheres.

Ball valve selection guide

Application Examples

One of the most common ball valves application is in residential water supply lines. We will describe the selection process for this ball valve based on the steps described above.

Type of operation: We can choose a manual ball valve because the application does not require automation and can be operated manually.

Loop function: In this case, we can choose a 2-way ball valve with a direct flow path.

Housing material: Brass housing is suitable because it is compatible with water.

Seal material: We should choose the PTFE seal because it is compatible with potable water.

Connection type size: We can choose standard/threaded ball valves for potable water applications.

Flow coefficient (Kv): We can calculate the Kv value by knowing the inlet, outlet, and water flow rate (in m 3) in residence. However, typical applications such as residential water supply lines can usually be sized based on the surrounding pipe size rather than the Kv value.

Pressure: Brass valves can withstand a maximum pressure of up to 80 bar, sufficient to achieve our goal.

Temperature: Valves should withstand a temperature range of -20°C to 60°C. Therefore, brass valves are preferred.

Approvals: If used for potable water, ensure the valve is approved for potable water applications.

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