Six-Petal Valve Getting Harder to Operate? Don’t Force It, Do These Two Things First

Six-petal valves control flow in powder pipelines through a simple, reliable design. However, when the hand lever or pneumatic cylinder starts feeling stiff, many operators try to force it or turn up the pneumatic pressure. This doesn't fix the underlying problem and often causes severe damage.

Step 1: Clean the Sealing Surfaces

When closed, the valve disc and seat fit tightly together. Over time, material powder gets trapped and compacted between them, forming a hard layer of caked powder. This buildup ruins the seal and dramatically increases rotational friction. To clean it:

• Switch the valve to manual mode.

• Rotate the disc to a half-open position.

• Scrape away the caked powder using a soft scraper, then blow the area clean with compressed air.

• Cycle the valve manually a few times. Operation will usually feel noticeably smoother right away.

Step 2: Check Shaft Bushing Lubrication

If operation remains heavy after cleaning, inspect the disc shaft bushings. Dust can enter the bushings during long-term operation, drying them out or the grease inside may age and lose efficacy.Add an appropriate amount of high-temperature resistant lubricant to the grease nipple on the bushing, then manually open and close the valve multiple times to allow the lubricant to distribute evenly. If the operation becomes noticeably lighter after lubrication, the issue is likely related to lubrication, and regular lubrication should suffice. If the operation remains heavy even after these two steps, the disc or seat may have deformed, and at that point, consider replacing the entire valve body or the disc assembly.