We all have access to water supplies in our homes and residential buildings. At the same time, wastewater from our residencies moves towards the main sewage drain. Both processes are inevitable as we cannot do away without them. Water flowing towards our home or out as wastewater must go without turbulence.
The backflow of water is a common shortcoming in such cases. The use of a check valve is the best solution to handle backflow. Check valves are efficient and responsive products that lessen the concerns of backflow. Let’s study check valves in detail.
What are Check Valves?
Check valves are non-return mechanical valves that allow single-sided flow. They are famous for their unconventional way of preventing the backflow of liquids. They also hinder overpressure threats by maintaining consistent pressure throughout the system. These properties of check valves make them best for water and wastewater treatment.
Check valves do not need any external power to operate. Instead, they work by fluid pressure when it flows through the valve body. There is a movable closure element in check valves. When fluid enters, it allows the automatic opening of the component in one direction only. The piece closes as soon as the fluid moves across. This is how it maintains the prevention of backflow.
Working Mechanism of a Check Valve:
Check valves offer an effective working that depends on the parts of the valve. The different components of a valve work together to produce desired results. Then, a check valve is enabled to prevent the backflow of a flowing liquid. The valve body consists of a closing element and other parts. The feature can be a diagram, ball, or disc per the valve type.
When fluid enters through the inlet in forward directions, it faces a closure element. A pressure difference lies between the inlet and outer port due to fluid pressure. This fluid pressure forces the part to open and move away from the seat, which opens the valve.
To deal with the backflow condition, check valves have an adaptive mechanism. If the pressure at the inlet port decreases than the outlet, the liquids tend to reverse. The check valve’s sprig mechanism closes the ball or disc element and secures the space with a seal. The fluids, thus, cannot go back towards the inlet port. This is how a check valve maintains its working mechanism.
|Product Name||Swing Check Valve|
|Material||Lead-free Brass, Bronze.|
|Size||1/2 – 2|
|Temperature Range||-20°C to -110°C|
|Working Pressure||16 Bar|
|Applications||Water Supply, Wastewater treatment, Oil industries, Chemical processing, Marine Applications.|
Applications of Check Valves:
Here are the best check applications in the plumbing industry and other uses.
- Water Supply System: The water distribution systems are extensive applications of check valves. Their primary purpose is to keep drinking water separate from contaminated water. They check the backflow of water in water mains and booster pump stations.
- Plumbing Systems: Plumbing systems must also prevent fluid from moving backward. For this purpose, they install check valves in significant numbers. They suit the duties of irrigation, sump pumps, and water heaters in plumbing.
- Wastewater Treatment: Wastewater is crucial to reach the main sewage drains. The backflow of wastewater can result in foul odor and even toilet backflow. Check valves take wastewater to treatment plants or main drains without backflowing.
- Chemical Reactions: Check the valve’s function in chemical reactions for efficient carrying out. They regulate corrosive chemicals and liquids in reaction chambers. These valves block the backflow of contaminations or other elements from backflowing.
- Pumps and Compressors:
The discharge part of the pumps and compressors often have check valves. It prevents them from water hammering, which occurs due to sudden changes in the velocity of a liquid. Check valves also prevent reverse rotation of the equipment and media backflow.
- Fire Protection System:
Fire sprinklers use check valves to regulate water flow in one direction. It ensures water moves straight from the source to the sprinklers without backflowing.
- Irrigation Systems: Check valves serve agriculture by preventing drainage and backflow of water. The drainage may occur after turning off the water supply, which we can control with the help of a check valve.
- Shipbuilding: Blocking water flow is crucial when the ship is not pumping. For this, check valves at particular locations to prevent the water flow from the bilge.
Best Check Valves for Water Pipelines and Wastewater Treatment:
Here are the five best check valves for water pipelines and wastewater treatment.
Swing Check Valves:
Swing Check Valves are relatable for homogeneous fluid applications. They consist of a hinge(swing) that attaches itself to the body, disc, and seat. The disc rotates when fluid achieves a specific flow rate. It gets into a horizontal position and lets the juice flow forward. Then, it returns to the valve seat to prevent liquid from returning. These are the best wastewater treatment check valves that fit water supply systems. They usually suit applications with moderate flow rates.
Ball Check Valves:
Ball check valves are essential in their structure and function. They have a ball as a closure element, moving away and returning. The ball lifts upon arrival of the fluid at a specific pressure with the help of the seat. The shape of the chamber is so that it guides the ball in sealing and allowing fluid. As the flow moves across, the ball returns to create a seal. These valves are best for wastewater, water supply, and industrial usage to some extent.
Diaphragm Check Valves:
Diaphragm check valves use a diaphragm to regulate flow in one direction only. They also need an actuation power of fluid pressure to operate. When the fluid reaches the diaphragm, it lifts due to the stress and gives passage for flow. This type can handle abrasive fluids due to the efficiency of the diaphragm. The diaphragm retains its original position to prevent backflow when the pressure lessens after fluid flow.
Piston Check Valves:
Piston check valves have a piston-shaped closure element. It shares the exact working mechanism as diaphragm check valves. The piston moves away from the seat, receiving pressure from fluid. Then, it blocks the passage by returning to its previous state. This state, indeed, is the one which is responsible for avoiding backflow.
Spring-loaded Check Valves:
Spring-loaded check valves are one of the top water supply check valves. They work based on a spring mechanism. A closure element, a disc or diaphragm, connects with the spring. The fluid pressure overcomes the spring force during forward flow. It lifts the closure element and allows passage for fluid. The path closes if the liquid tends to flow back.
Advantages and Disadvantages of Check Valves:
|They maintain the integrity of a system by preventing fluids from backflow.||The closing element may sometimes cause obstruction, leading to pressure drop.|
|Check valves do not need any electricity or external power actuation. They have an automatic system that responds to fluid pressure and flow.||Some types of check valves may have higher costs than others.|
|Some types of check valves have designs that reduce water hammer effects.||They do not have flow rate control capacity as their function is to allow unidirectional flow.|
|They need very little maintenance due to basic design and a few parts.|
|Check valves increase equipment life by saving it from sudden blockages or pressure changes.|
Best Materials for Check Valves:
There are tons of different materials available for check valves. However, the selection depends on your particular installation and application. Some of the best materials for check valves are below.
- Stainless Steel.
- Ductile Iron, Cast Iron.
How to Select the Right Check Valve?
Here are a few factors to consider while selecting a check valve.
- Always select a check valve that matches your system’s flow direction. You can choose specific types as per flow characteristics.
- You must ensure that your pipeline size syncs with your purchased valve size.
- Select a check valve material that suits the flowing media; for example, brass is excellent for abrasive fluids.
- The installation of the selected valve should go with your system’s installation method.
- It is best to select a check valve that needs less operating cost and maintenance.
Can we use check valves for gases as well as liquids?
We can use check valves for both gases and liquids. The valve should be compatible with the fluid’s properties and conditions.
Can we install check valves in any orientation?
No. Instead, they should be installed according to their flow direction shown by an arrow symbol.
What are the disadvantages of using check valves?
In some situations, check valves can cause pressure drops, noise, and water hammer.
In a nutshell, check valves are efficient and high-performance products. Selecting an efficient check valve elevates the performance by preventing backflow. If the backflow problem is not considered, it can turn out problematic. Plumberstar is a B2B, well-known valve supplier. They have one of the best check valve catalogs that speaks for their quality and optimization. Their expert team will handle you throughout the selection and purchase process.