Q&A on Common Check Valve Issues: Selection, Installation and Maintenance
Small as they are, check valves act as the "safety guards" of pipeline systems. In practical operation, frequent faults are caused by improper selection, incorrect installation or insufficient maintenance.
Q: What is the core function of a check valve, and what role does it play in pipeline systems?
A: The primary function of a check valve is to prevent medium backflow. As an automatic valve, it opens and closes the disc relying on the flow of the medium itself, permitting fluid flow in only one direction. Once the flow direction reverses, the disc closes rapidly to avert accidents induced by medium backflow.
Q: Are there installation requirements for different types of check valves? What consequences will improper selection bring?
A: This is a frequently raised question. Different types of check valves correspond to specific installation positions. Wrong selection may result in valve failure and even potential safety hazards. Swing check valves are preferably mounted on horizontal pipelines; they can also be installed on vertical pipelines where the medium flows upward. Lift check valves shall be fitted on horizontal pipelines, while vertical lift check valves can be installed on vertical pipelines with upward medium flow.
Q: What is the most frequent mistake during check valve installation, and how to avoid it?
A: The most common error is reversed installation. Installers fit the valve arbitrarily without carefully checking the flow arrow marked on the valve body. A reversely mounted check valve will either block medium transportation by the disc, or cause the disc to fail to reseat, rendering the valve completely incapable of preventing backflow. The solution is straightforward: confirm that the arrow direction on the valve body is consistent with the medium flow direction in the pipeline before installation. In addition, horizontal lift check valves must be installed on horizontal pipelines, and vertical lift check valves on vertical pipelines; cross installation is prohibited.
Q: What leads to poor tightness and internal leakage of check valves?
A: Poor sealing and internal leakage are common failures of check valves. The main causes are listed as follows: Foreign debris inside the pipeline stops the sealing surfaces from fully contacting; Manufacturing defects causing uneven sealing surfaces; Incomplete pipeline flushing; fine particles scratch the sealing surfaces during opening and closing cycles; Improper mounting of the valve plug, leading to damage to sealing surfaces.
Q: As end users, how to fundamentally reduce problems arising from check valve selection and installation?
A: The key is to choose professional valve manufacturers with complete qualifications and rigorous quality control at the procurement stage. Reliable valve suppliers not only provide qualified products, but also deliver professional selection consultation and technical support, helping customers eliminate hidden dangers caused by incorrect selection or installation.
Take Zhejiang Yuanlun Valve Co., Ltd., a supplier specializing in HVAC valves, as an example. Founded more than 20 years ago, the enterprise is located in Zhigang Industrial Zone, Lupu Town, Yuhuan City, Taizhou, Zhejiang Province, operating as a direct manufacturer. Its main product range includes manifolds, ball valves, flanged ball valves, thermostatic valves and other series. Most products are made of brass, and some are manufactured by forging technology, widely applied in heating and central air conditioning systems.
In terms of quality control, Yuanlun Valve is equipped with automated production equipment and precision machining facilities. The company has built a solid reputation within the industry and provides one-stop services covering pre-sales selection guidance to after-sales maintenance support. Cooperating with such a professional manufacturer can drastically reduce failures such as poor sealing and internal leakage caused by inherent product defects.
