Check valve is a self-acting valve type allowing forward flow or reventing reverse flow. Other terms used include back pressure valve, non-return valve, reflux and retention valve.
Check valves are available with different spring rates to give particular cracking pressures. The cracking pressure is that at which the check valve just opens. If a specific cracking pressure is essential to the functioning of a circuit, it is usual to show a spring on the check valve symbol. The pressure drop over the check valve depends upon the flow rate; the higher the flow rate, the further the ball or poppet has to move off its seat and so the higher the spring force.
A check valve may be defined simply as a mechanical device typically used to let fluid, either in liquid or gas form, to flow through in one direction. They usually have two ports or two openings – one for the fluid entry and the other for passing through it. Often part of household items, they are generally small, simple, and inexpensive components. They also come in various sizes and costs. Following is a review of some of the models available in the market.
Check valves are generally used in pipes and other similar devices or equipment to enable the materials or fluids to flow in only one direction while preventing a reverse flow from happening. Although this control valve comes in different forms, sizes, and functions, they typically operate on the same principle. Likewise, most of these valves have 3 common parts or components
For the proper maintenance of your installed check valve, it is always best to follow the recommendations of the manufacturer especially where repairs or replacements are involved. This is because different products are made of different materials and parts; and therefore, must be maintained differently. However, there are some common maintenance steps that you can undertake on your own to compliment the proper procedures prescribed by the manufacturer.
A Check valve is normally used in piping systems to decrease the flow reversal and allow the material, which may be gas or liquid, to flow freely in just one direction. These devices are automatically activated when liquid flows in the pipeline. They can also be installed in some systems that tend to overheat or get contaminated as a result of reverse flows; these contraptions are then used to prevent such occurrences.