Industrial non-rising stem gate valves are another type of gate valve commonly used in various industrial applications. Unlike rising stem gate valves, where the stem rises and lowers as the valve is operated, in non-rising stem gate valves, the stem remains stationary while the gate moves up and down within the valve body. Here’s an overview:

1. Design: Non-rising stem gate valves consist of a gate, a stem attached to the gate, a bonnet, and a handwheel or actuator. The gate moves up and down within the valve body to control the flow of fluid, while the stem remains stationary. The stem is threaded into the gate and rotates with the handwheel or actuator, transmitting the motion to the gate.

2. Gate: The gate in a non-rising stem gate valve typically moves vertically within the valve body to open or close the flow passage. When the valve is open, the gate is lifted or lowered into the bonnet, allowing fluid to pass through. When closed, the gate seals against the valve seat to prevent flow.

3. Stem: The stem in a non-rising stem gate valve is threaded into the gate and remains stationary while the valve is operated. Instead of rising and lowering with the gate, the stem rotates with the handwheel or actuator, transmitting the motion to the gate to control the flow of fluid.

4. Bonnet: The bonnet in a non-rising stem gate valve serves as a cover for the valve body and provides a seal to prevent leakage. It is typically bolted or threaded to the valve body and may include packing or other sealing arrangements to prevent fluid from escaping around the stem.

5. Handwheel or Actuator: Non-rising stem gate valves are operated manually using a handwheel or equipped with pneumatic, hydraulic, or electric actuators for automated operation. The handwheel or actuator is connected to the stem and is used to rotate the stem, raising or lowering the gate to control the flow of fluid.

6. Materials: Non-rising stem gate valves are available in various materials to suit different applications and operating conditions. Common materials include carbon steel, stainless steel, cast iron, bronze, and various alloys. The choice of material depends on factors such as the fluid being handled, temperature, pressure, and corrosion resistance requirements.

7. Applications: Non-rising stem gate valves are widely used in industries such as oil and gas, petrochemical, water treatment, power generation, and manufacturing. They are suitable for both on-off and throttling applications and can handle a wide range of fluids, including water, steam, oil, gas, and chemicals.

8. Advantages: Non-rising stem gate valves offer several advantages, including a compact design, suitability for installations with limited vertical space, and ease of operation. They provide reliable sealing and are often preferred in applications where rising stem valves are impractical due to space constraints.

9. Maintenance: Regular maintenance is essential to ensure the proper operation and longevity of non-rising stem gate valves. This may include lubrication of moving parts, inspection of seals and gaskets, and cleaning or flushing of the valve internals to remove debris. Proper maintenance practices help prevent valve failures and minimize downtime in industrial processes.

Overall, non-rising stem gate valves are versatile and reliable components used in a wide range of industrial applications to control the flow of fluids. Proper selection, installation, operation, and maintenance are essential to maximize the performance and efficiency of non-rising stem gate valves in industrial processes.