What are the differences between ball valves, globe valves, gate valves, and butterfly valves?

Butterfly Valve  

For small pipe diameters, butterfly valves don't show significant advantages. But at DN300, DN500, or DN800, the benefits become apparent. As pipe size increases, valve selection can no longer focus solely on sealing and flow resistance. A simple butterfly disc mounted on a shaft offers compact structure, short installation length, and easy weight control. Thus, butterfly valves are widely used in circulating water, cooling water, HVAC, water supply and drainage, fire protection, and large-diameter water systems.

Butterfly valves have their own characteristics: even when fully open, the disc remains within the flow path. Therefore, local resistance still needs to be calculated in hydraulic design. For pump discharge lines or high-flow circulation pipes sensitive to pressure drop, the valve’s resistance coefficient must be included in system calculations.

Modern butterfly valves come in many designs. Standard mid-line soft-sealed models are common in water systems, while double-offset, triple-offset, and metal-sealed types are suited to different temperature, pressure, and sealing requirements.

Differences and Selection Criteria Among the Four Valves  

When faced with a new pipeline, follow this sequence:

First, determine the valve’s function: shut-off, isolation, throttling, or regulation. Clarify this point first.

Then, identify the medium. Clean water is easy to handle. But if the medium is steam, natural gas, corrosive fluids, slurries, or solid-laden particles, the choice of seat and sealing surfaces will immediately change.

Third, what are the design pressure and design temperature?  

It's important to note that we're referring to design pressure and design temperature—not just the normal operating values shown on instruments.  

Valve pressure ratings cannot be considered independently of temperature and material. For example, a valve marked with PN or Class rating may have different pressure capacity under high-temperature conditions, which must be verified against the corresponding material’s pressure-temperature rating.

Fourth, consider the size (nominal diameter), pressure drop, and actuation frequency.  

A DN50 valve and a DN1000 valve, even if both perform the same shut-off function, require different considerations. A valve operated twice a year versus one operated dozens of times per day will differ in terms of actuator type, sealing components, and maintenance requirements. Only after confirming these conditions should you proceed to select the body material, seat material, connection type, actuator, and accessories. This ensures a logically complete valve selection.

Selection should not be rigidly fixed. Although previous designs worked without issues, they can only serve as references. If the new system has different pressure, temperature, flow rate, or actuation frequency, the original selection must be re-evaluated. This is especially true for the same medium—people often develop a habit of using similar valves. Even though all involve water, requirements vary significantly between main circulating lines, pump discharge, heat exchanger branches, and flow control lines. Similarly, for steam, pipelines at 1.0 MPa and higher pressure levels require reevaluation regarding temperature, materials, sealing, and valve structure.

Therefore, during selection, follow this logical sequence: first determine the application, then identify the medium; next verify pressure, temperature, and nominal diameter; finally, specify materials, sealing, connections, and drive mechanisms.