Adjustment valve installation and method for improving life

When installing the regulating valve, it's essential to pay attention to several key points. First, before installation, make sure to remove any dust or debris that may have accumulated during storage. Keep the area clean throughout the process to avoid damaging the seat and trim. It’s a good practice to cover the open flange with a protective cap if it won’t be welded on the same day.

Second, ensure the arrow on the valve body aligns with the flow direction of the medium. This is crucial for proper operation and performance.

Third, regulating valves are precision components, so they must not be subjected to stress from pipe deformation. The flanges and pipes should be aligned properly and installed vertically. Additionally, support the pipeline correctly to prevent bending under the weight of the valve.

Fourth, when welding the valve to the pipe, special care is required. Inadequate welding or residual stress can cause deformation. Make sure to prevent welding slag from entering the valve, as it can damage internal parts like the valve plug and seat. If slag lands directly on the plug, it can interfere with its movement and reduce the valve’s efficiency.

Fifth, during pipeline testing and blowing, remove the regulating valve and replace it with a straight section of pipe. This prevents debris such as welding slag or metal shavings from getting stuck between the plug and seat. After removal, cover the flange end with plastic sheeting to protect it.

1) Extended Working Method

To prolong the life of the valve, operate it at a higher opening initially, such as 90%. This helps reduce cavitation and erosion on the spool head. As the spool wears, the flow increases, and the valve closes again. This cycle gradually reduces wear and extends the overall lifespan. A larger opening also minimizes erosion, making it more efficient than operating at a smaller or mid-range opening. Some chemical plants have reported a 2-5 times increase in valve life using this method.

2) Reduce S to Increase Working Opening

Decrease the pressure drop by adjusting the system. Close the manual valve connected in series until the regulating valve reaches an ideal working opening. This is especially effective when the valve is originally selected for a small opening, and it’s a simple and efficient solution.

3) Reduce Caliber to Improve Life

By reducing the diameter of the regulating valve, you can increase the working opening and improve its longevity. For example, changing from DN32 to DN25 or replacing the valve core with one that has a smaller seat diameter can significantly extend service life. One chemical plant saw its valve life double after replacing a throttle DG10 with DG8.

4) Transfer Damage Location

Shift the most damaged areas to less critical locations, helping to protect the sealing and throttling surfaces of the valve seat.

5) Enlarge Throttling Channel

Thicken the valve seat to create a longer throttling channel, which can help reduce erosion and improve durability.

6) Change Flow Direction

The flow direction affects how cavitation and erosion impact the valve. A flow-open type directs the flow toward the opening, causing damage to the sealing surface. In contrast, a flow-closed type directs the flow toward the closed position, protecting the sealing surface and extending the valve’s life.

7) Use Special Materials

Use materials resistant to cavitation and erosion, such as those designed to withstand honeycomb-like damage or streamlined grooves caused by high-speed fluid flow.

8) Modify Valve Structure

Changing the valve structure or selecting a more durable model, such as a multi-stage or anti-cavitation valve, can significantly improve the valve’s service life.