Sanitary non return valve is designed to keep the fluids in the direction of flow which is safe and hygienic. The functioning of the different one-way valves is discussed below. There are many kinds of valves in use today. The valves are mechanisms for regulating the fluid flow through the channels onwards towards their destination. The one-way valve or the sanitary non return valve or the clack valve is a device which ensures that the flow of fluids is maintained in a unilateral flow. It is a moot point why one needs a valve in the first place.
Fluids flow from a region of higher potential to a region of lower potential. Once there is a change in the equation with respect to either the potential or the factors leading to the potential there are chances that the flow will change its course.
Many conditions of fluid flow demand that the flow be strictly monitored to ensure that the flow is not having any back flow. If the amount of fluid in the upper channel is too much then there are chances that the flow would not be sustained. It is in situations like this that one uses the non-return check valve or the one-way valve.
Many kinds of sanitary non return valve are in existence but the most used one are discussed here. The different kinds of one–way valves are diaphragm valves, ball valves, hinge valves and lift valves.
In the sanitation department, it is absolutely essential that there is no back ward flow, there is no contamination of the pure water and there is no leakage which could result in sickness or pollution of the atmosphere. This is because the fluid in the pipe is full of bacteria and could cause a serious health hazard if it were let loose. Using valves to regulate the flow and thereby control the processes is most essential.
The ball one way valve, has a ball which in most case is operated by the upstream pressure abut it may not be so. It may sometimes require a back flow to cause the valve to close and that is why this kind of valve is not recommended for use when there is danger of contamination.
The hinge type one way valve is more popular and works on the principle of difference in pressure. The edges of the closing flanges are oriented in such a manner as to close when the pressure is opposing the direction of flow. These kinds of valves are used when the flow is too heavy or the requirement of safety is too great.
The stop valve is one which is manually operated; it has no concerns about the flow characteristics or the upstream or downstream pressures. It is only used to regulate the flow in conditions which are determined by the external factors and once the decided, the valve is hut off.