Working condition
| Pressure Rating | CLASS 150 to CLASS 600 |
| Nominal Size | NPS ½ to NPS 16 (DN 15 to DN 400) |
| Seat Leakage Class | ANSI FCI 70-2 CLASS VI |
| Applicable Media | polyethylene powder, polypropylene powder, |
| Temperature Rating | Up to 150°C |
| Cycling Life | 100,000 to 1,000,000 times per year |
| Stroking Speed | Typically 1–5 seconds |
| Actuation Methods | Pneumatic |
Pain Points and Proposal
1. External Leakage: packing wear due to frequent opening/closing without any compensation, finally external leakage occur.
2. ① High-frequency opening and closing as well as high-speed movements are likely to cause bonding of metal sealing pairs, resulting in premature damage.
② Solid powders in the medium tend to accumulate in the spring chamber, causing the valve's opening and closing torque to gradually increase, thus leading to jamming.
③ Ultra-fine particles easily accumulate in bushings, bearing pocket, seats, etc., causing scratches on the stem surface, increased valve torque, or even cannot operate the valve.
3. Internal Leakage:
① High-frequency cycling and rapid actuation easily cause premature damage due to metal to metal "bite" by sealing surface pairs.
② Wrong dimensional tolerance chain design leads to inconsistent product quality.
1. Anti-galling coating
2. Reasonably designed anti-seizing clearance based on finite element analysis (FEA)
3. Metal triangular self-sealing design with sufficient elastic recovery compensation
Reference
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Shenhua Ningxia Coal Industry Group - High Frequency PDS Ball Valve
Process: Lummus Novolen polypropylene process
Size:DN65
Temperature:150℃
Pressure Rate:CLASS 600
Fluid: polypropylene powder
Raw material:F316
On-off frequency:1,500,000 times per year