The gate which regulates the sluice is a valve known as the sluice valve. These gates are made to be sealed in one direction and are typically used to regulate water levels and flow in streams and canals. Sluice gate valve can also be used in wastewater treatment plants.
What Is a Sluice Valve?
A gate valve or a Sluice gate valve is described as a valve that uses a gate or wedge shape disk that slides perpendicular to the flow of the fluid into or out of the pipeline. When the gate valve is fully opened, the disk of the gate valve is completely separated from the flow. This practically gives no opposition to flow. Due to this, very little reduction in pressure is experienced as the fluid moves through the gate valve.
The sluice gate valve is the common type of valve that is used in process plants to handle slurries. In operation, these valves are either fully opened or fully closed.
Sluice gate valves cannot be used for throttling as accuracy cannot be achieved using them. The high flow velocity in the partially open valve can cause disk and seat surface erosion and can also cause vibration and noise.
How Does a Sluice Valve Work?
The sluice gate valve is controlled by a lifting gate or wedge, so that flow of water can move without obstruction. The top end of the stem has a hand-operated wheel or a motor that raises and lowers the doors, and the lower end has a circular or wedge gate to obstruct water flow. It employs a threaded stem, so the valve must turn several times to shift from the open position to the closed position, and vice versa to stop water hammering.
There are mainly two main types of the spindle that are used to raise the gate in a sluice valve.
- Raising Spindle type valve: In this type of valve, the spindle/stem is connected to the gate. While operating the spindle valve does not rotate with the handwheel but raised with the spindle.
- Non- Raising spindle type valve: In this type of valve design the spindle is threaded and the gate is also threaded internally where it is attached to the spindle. While operating the valve stem does not raise from its place but rotates in its place to raise the gate using threads.
The dimension of the sluice valve is usually the same as the size of the main valve that is up to a diameter of 300 mm. For larger diameters, the size of the valve is roughly two-thirds the size of the main valves.
The valves are mounted in a valve chamber fitted with caps or handwheels for operation. The method of opening the valve can be clockwise or counter-clockwise, indicated at the outer end of the spindle.
Where Do We Use The Sluice Valve?
Sluice gate valves are commonly used to cut off the liquid flow and cannot be used as a flow regulator. In a completely open position, there is no obstacle in the flow path by the sluice valve, which result in very little flow-resistance. When you move the gate, the size of the open flow path normally varies in a non-linear way. This indicates that the flow rate does not vary with the stem travel uniformly. Depending on the structure, a partially opened gate will vibrate due to the flow of fluid. Sluice valves are often used for larger pipe diameters as they have easy and simple construction than other types of large valves.
At high pressure, friction may become a concern. As the gate is forced against its guide rail by the force of the medium, it becomes more difficult to operate the valve. Large gate valves are often equipped with a bypass that is controlled by a smaller valve so that the pressure can be decreased when the gate valve is operated.
Sluice Valve Installation And Maintenance
Sluice gate valves are very easy to use and are long-lasting when their installation is done in a proper way and the maintenance is carried out in a regular interval.
- Installation of Sluice valve.
- These valves can be fitted in any orientation but if a large valve is to be used then it should be fitted in an upright position for ease in accessibility to operate the sluice valve.
- The material of the valve body, stem, and disk are to be checked before installation.
- It is to be verified that there is no damage to the valve while transportation or storage. Also check the valve for debris, rust, wrapping material, and dirt before installation.
- Make sure flanges in both pipe and valve are matching after this connect and centre the valve. Insert the bolts and tighten them with even pressure so that the sealing of the valve between the pipe is proper.
- Once the installation is finished try to operate the valve several times to make sure it is in a correct position and did not move from its desired place at the time of installation.
- Testing of the sluice valve is to be carried out with a proper procedure provided by the manufacturer to make sure the valve is working properly and can handle working parameters without any problem.
- Maintenance of Sluice valve.
If the valve is not used regularly it is to be operated and maintained once a month to make sure there are no blockages or wear. Before this, make sure the system pressure is relieved and is not pressurised. To remove the gate for inspection, the bonnet and stem are to be removed. After this check, the sluice gate & guide for any damage or wear and refit/replace the parts after the inspection.
Difference Between Gate Valve & Sluice Valve
Sluice valves and gate valves are somewhat different in operation and usage. A gate valve can be a good option for in-line sealing and sludge applications. But when it is needed for managing the flow in a sluice or stream, the sluice gate valve is the best option for your application.
NTGD valve is an experience sluice valve manufacturer, feel free to contact us if you have any question