Used to restrict fluid flow to a certain direction, check valves are employed in the vast majority of industrial processes. At DFT® Inc., we provide a wide range of check valves for use in diverse industrial applications. Our spring-assisted in-line check valves, for instance, are specifically designed to prevent water hammer by eliminating the risk of reverse flow. And, if sizing is done to account for flow rather than line size, these high-performance valves will operate reliably and efficiently for years, without the need for extensive maintenance.
In-Line Check Valves
The experts at DFT® often help clients assess their unique check valve requirements; our check valve sizing program allows us to easily determine required valve sizes before actual setup, eliminating the risk of design errors and delays. DFT® check valves can be installed in-line in any orientation; valve operation will not be hampered in any way by the specific orientation chosen, provided the flow direction is in line with the valve design (as indicated by an arrow on the valve casting).
However, for a downward flow, these check valves need to be modified slightly to support the additional weight of the disc and any static head that may be involved. While silent check valves can be employed in vertical piping or in installations requiring constant controllable pressure, swing valves should only be used in horizontal pipe runs, in which minor flow variations are expected.
When using swing check valves, users are afforded limited pressure control, as there is less control over valve opening and closing. Therefore, this type of valve is usually employed in less sensitive, large-scale pipelines carrying liquids, gases, or steam. To allow for enhanced performance, these swing check valves can be replaced by our GLC® Silent Check Valves or Excalibur® Silent Check Valves. These silent check valves have only one moving part and allow for greater flow variability than a conventional style swing check valve. Also, because the DFT Axial Flow Check Valves have so few moving components, they are more resistant to wear and tear and can maintain a longer lifespan.
However, the GLC® model is not considered a “dead-end” service valve. It is essential that the upstream, or seat end, of the valve be connected to the line until the pressure is relieved from the downstream end. The seat end of the valve must always remain bolted to the mating flange when the valve is exposed to downstream pressure in order to avoid possible blowout of the internals, as the retaining screws do not account for direct exposure to downstream pressure. In addition to eliminating water hammer, appropriately sized silent check valves can greatly improve system safety, protect critical system components like pumps, and improve overall system life while reducing maintenance costs.
DFT® check valves are specially designed to improve the efficiency and safety of your industrial processes, and our team of experts is ready to assist in identifying the ideal model for your specific needs.
To learn more about our valve solutions, and why it may be beneficial to replace your current valves with DFT® non-slam check valves, download our new eBook, “Non-Slam Check Valves vs. Swing Check Valves.”