What Are Non-Return Valves?
When working with various fluids that are traversing within enclosed systems, it is very beneficial to have as much control over flow and movement as required for safety, performance, etc. In order to achieve this, it is common to use valves which are devices with adjustable orifices and elements that allow flow to effectively be manipulated. Based on one’s needs, there are a number of valves to choose from, each varying in its specific design and capabilities. One popular type of valve for control is the non-return valve, and this device is a single-way valve that only permits fluids to flow in a singular direction. This is crucial when fluids cannot be allowed to move upstream, whether this is due to issues such as increased fluid pressure, contamination, performance loss, etc. In this blog, we will discuss the functionality and design of non-return valves, allowing you to have a better understanding of the options available for you and when they can be used.
Like many valves, non-return valves consist of two openings in the form of an inlet and an outlet. To control flow, a type of closing element will be present between the two openings. As fluids enter the valve inlet, fluid pressure will force the closing member open so that materials can move unabated. However, this fluid pressure can only keep the closing member open when applied from the inlet side. If any fluids begin to flow backward, the fluid pressure will actually increase the force holding the closing member shut. While this process is quite simplistic, it is proven to be quite reliable for a large number of needs. Additionally, the adjustment of the closing element is completely automatic.
Non-return valves are important in a number of applications, often finding use in pump discharge components, transportation fluid systems, nuclear industry lines, aircraft assemblies, mixing chambers, and so much more. Within mixing chambers, as an example, non-return valves are essential for standard operations as to prevent contamination. Without the ability to prevent backward flow, fluids would be able to move into the original sources and mix. While the issue of mixing may not be as important in some other applications, backward flow can still simply deter performance, making it essential to deter.
With multiple non-return valve types being available on the market, the choice will generally come down to what working mechanism one wishes to rely on. With swing check NRVs, the stopping element is an adjusting part that swings on a hinge or trunnion. Meanwhile, ball NRVs utilize a spherical ball that adjusts to block flows, and spring loading may assist in movement when force is applied. It is important to consider your particular needs, as some non-return valve types may be more suitable for certain applications and fluids when compared to others. Aside from the already mentioned types, other common options include stop check, diaphragm, lift check, in-line, folding disc, and tilting disc non-return valves.
There are a few specific things to keep in mind when choosing non-return valves, common considerations including the type of fluid being transported, the location of the valve, pressures and temperatures, maximum flow rates, desired closing times, installation type, and cost. By keeping these factors in mind, you can better find a valve that provides smooth operations, low maintenance, and long-term operations. Nevertheless, non-return valves will still require regular inspection and maintenance even when the most optimal choice is made as a result of standard operations.
If you are in the market for new, used, obsolete, or hard-to-find valve parts for a new installation or just for maintenance, we have you covered here at ASAP Aviation Stock. All of our parts are sourced from top manufacturers we trust, and every purchase ships alongside all qualifying certifications and manufacturing trace documentation as applicable. As a result of our steadfast dedication to quality control and export compliance measures, we proudly conduct business with AS9120B, ISO 9001:2015, and FAA AC 00-56B accreditation. If you would like a customized quote for your comparisons, fill out an RFQ form on our website or give us a call or email. Get in touch with a team member at your earliest convenience and see how we can serve as your strategic sourcing partner for all your operational needs!
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