In industrial pipeline systems, check valves play an indispensable role in preventing fluid backflow, which could lead to equipment damage, process disruptions, or even safety hazards. Among them, cast steel swing check valves have emerged as reliable “guardians” for ensuring unidirectional fluid flow in numerous fields, thanks to their unique structural designs and dependable performance.
Cast steel swing check valves feature ingenious structural designs. The valve body is constructed from high-strength cast steel materials, such as WCB and WC6. After heat treatment, it exhibits excellent strength and toughness, capable of withstanding pressure ratings ranging from PN16 to PN160 and operating within a temperature range of -29°C to 425°C. This enables stable operation under various complex working conditions. The core component, the valve disc, is connected to the valve body via a disc shaft, which is installed in the rotational shaft hole of the valve body, allowing the disc to rotate around the disc shaft. The sealing surfaces of the valve seat and the valve disc undergo precise machining and grinding to ensure optimal sealing performance. In some valves, wear-resistant materials like Stellite alloy are overlay-welded on the sealing surfaces to extend their service life.
In terms of working principles, when the fluid flows forward in the pipeline, the fluid pressure pushes the valve disc to rotate and open around the disc shaft. The opening angle of the disc typically ranges from 60° to 90°. At this time, the flow path is unobstructed, and the fluid can pass through with minimal resistance. When there is a tendency for the fluid to flow backward, the combined action of fluid pressure and the self - gravity of the valve disc causes the disc to close rapidly, fitting tightly against the valve seat and preventing backflow, thus achieving the unidirectional shut-off function. This automatic operation relying on fluid pressure and gravity does not require external actuation, ensuring stable and reliable operation.
Cast steel swing check valves offer significant performance advantages. Firstly, they have relatively low flow resistance. Compared with lift check valves, the disc of a swing
check valve creates less obstruction to the fluid after opening, making them suitable for large-diameter and high-flow pipeline systems. Secondly, they provide excellent sealing. The precise design of the sealing surfaces and the use of wear-resistant materials effectively prevent fluid leakage. Thirdly, they have strong impact resistance. The robust structure of cast steel enables them to maintain stable performance even under fluctuating fluid pressures or water hammer impacts. Fourthly, they have a wide range of applications, suitable for transporting various media, including water, steam, oil products, and gases.
The application scenarios of cast steel swing check valves are extensive. In the petrochemical industry, they are commonly used to prevent the backflow of materials in reaction vessels, ensuring the normal progress of chemical reactions. In the steam pipeline systems of the power industry, they can prevent steam backflow from damaging equipment such as steam turbines. In water supply and drainage systems, they prevent water from flowing backward when the water pump stops operating, protecting the pump and pipelines. In natural gas transmission pipelines, they also ensure the unidirectional flow of natural gas, maintaining the stability of the transmission system.
With the development of industrial technology, cast steel swing check valves are constantly innovating. In the future, they will evolve towards lower resistance, superior sealing, and intelligent monitoring, further enhancing their application value in the field of industrial fluid control and providing more robust support for the stable operation of various industries.
