How Are Industrial Valves Classified By Working Function?

How Are Industrial Valves Classified by Working Function?

Industrial valves are essential control components of fluid pipeline systems, widely used in oil and gas, petrochemical, power generation, water treatment and municipal engineering. With the diversification of industrial working conditions, valve types have become increasingly rich, and different valves are designed for specific fluid control needs. To standardize engineering selection, unify industry standards and improve pipeline operation efficiency, the industry has formed a mature classification system based on valve working functions. Unlike classification by material, pressure grade or connection mode, functional classification focuses on the core working purposes of valves. This article systematically introduces the functional classification of industrial valves and their respective application characteristics through question-based subheadings.

Cut-off valves, also known as isolation valves, are the most widely used basic type of industrial valves, with the core function of fully connecting or completely cutting off pipeline fluid passages. This type of valve only supports two working states: fully open and fully closed, and is not suitable for fine fluid regulation. When fully opened, the internal flow channel is unobstructed with minimal fluid resistance; when fully closed, it achieves ultra-tight sealing to prevent medium leakage.

Common cut-off valves mainly include gate valves, ball valves, globe valves and plug valves. Each type has its own scenario advantages. Gate valves are suitable for large-diameter main pipelines with low resistance requirements; ball valves feature fast switching speed and excellent sealing performance, adapting to high-pressure and corrosive media; globe valves are widely used for medium and small-diameter industrial pipelines requiring reliable isolation. Cut-off valves are mainly applied in conventional fluid transmission pipelines, providing basic switch guarantee for pipeline maintenance, sectional isolation and daily start-stop operation, which is the most fundamental functional valve type in pipeline engineering.

Different from switch-only cut-off valves, regulating valves are professional functional valves designed for fluid parameter control. Their core working function is to adjust pipeline flow, pressure and flow velocity through changing the opening degree of internal passages. They can realize stepless adjustment between fully open and fully closed states, maintaining fluid parameters within the stable range required by industrial production processes.

Mainstream regulating valves include butterfly valves, straight-through regulating valves and intelligent control valves. High-end precision regulating valves represented by Emerson and Flowserve products can achieve micron-level accurate regulation, effectively solving fluid fluctuation problems in high-precision industrial production. These valves are widely used in petrochemical refining, thermal power generation, pharmaceutical production and chemical reaction processes, where fluid pressure and flow stability directly determine product quality and production safety. As the core regulating equipment of industrial systems, regulating valves ensure the continuity and standardization of industrial production.

Check valves, named one-way valves, are a special type of safety functional valves, whose unique working function is to prevent fluid backflow in pipelines. This kind of valve works automatically relying on fluid pressure difference without manual or electric driving control. When the fluid flows forward, the medium pressure pushes the valve core open to ensure normal fluid transportation; once the fluid reverses, the backflow pressure will push the valve core to close tightly, completely blocking the reverse flow channel.

Common check valve types include swing check valves, lift check valves and wafer check valves. They are mainly installed at the outlet of water pumps, compressor pipelines, long-distance transmission pipelines and multi-loop circulating systems. In industrial operation, sudden pressure fluctuation or system shutdown easily causes fluid backflow, which may impact precision instruments, damage power equipment and cause medium mixing. Check valves effectively avoid such risks, maintain one-way stable operation of fluid systems, and improve the overall safety and stability of pipeline networks.

Pressure relief valves, also known as safety valves, belong to emergency safety protection valves, serving as the final safety barrier of high-pressure pipeline systems. Their core working function is to release pressure automatically when pipeline pressure exceeds the rated safe value, so as to prevent pipeline overpressure burst, medium leakage and explosion accidents. Different from regulating and cut-off valves, safety relief valves are normally closed and only act in emergency overpressure situations.

When the internal pressure of the pipeline exceeds the preset threshold, the internal spring structure or pressure sensing device of the valve will be automatically opened to discharge excess fluid and reduce the system pressure to the safe range. After the pressure returns to normal, the valve will reset and close automatically. This type of valve is widely used in high-pressure industrial pipelines, pressure vessels, energy storage tanks and chemical reaction equipment, providing reliable emergency safety protection for high-risk industrial facilities.

In addition to the four mainstream functional valve types, there are various special functional valves customized for extreme working conditions and special industrial needs, supplementing the functional classification system of industrial valves. Special valves include exhaust valves, drain valves, cryogenic valves, high-temperature resistant valves and desulfurization valves, which are designed for single specific working scenarios and special media.

For example, exhaust valves automatically discharge accumulated air in pipelines to avoid air resistance affecting fluid transmission efficiency; drain valves clean residual media in pipelines to facilitate equipment maintenance; cryogenic valves adapt to ultra-low temperature working conditions of LNG projects. These special functional valves make up for the functional limitations of conventional valves, meet the diversified and extreme working condition needs of modern industrial engineering, and improve the completeness and professionalism of pipeline system operation.

In conclusion, industrial valves are functionally divided into cut-off valves, regulating valves, check valves, pressure relief safety valves and special functional valves. Each type of valve has independent core functions and targeted application scenarios, covering basic pipeline switch, parameter regulation, backflow prevention and emergency safety protection. The scientific functional classification provides a unified standard for valve selection, pipeline design and engineering operation. Reasonable matching of different functional valves and high-standard steel pipe systems can maximize the operational efficiency and safety of industrial fluid pipelines, supporting the stable and efficient operation of modern industrial infrastructure.