Ball Valve Seat & Seal Material Selection Guide
The specification of seat material PTFE, Nylon, PEEK, PCTFE, and Devlon V, and sealing material HNBR, Viton, and FFKM for trunnion ball valves covers temperature range, pressure rating, mechanical property (hardness, tensile strength, elongation), physical property (specific gravity, water absorption, and water absorption saturation), and service applications.
Seat Materl Application
| Properties | PTFE | NYLON | PEEK | PCTFE | DEVLON V | |||
| Temperature Range ℉ | -328~428 | -58~248 | -148~500 | -328~302 | -148~302 | |||
| Temperature Range ℃ | -100~200 | -50~120 | -100~260 | -200~150 | -100~150 | |||
| Pressure Rating | 150~600 | 150~1500 | 150~2500 | 150~600 | 150~1500 | |||
| Mechanical Property | Hardness (D) | 58 | 72 | 88 | 85 | 78 | ||
| Tensile Strength(MPa) | 14~34 | 55. 2 | 134 | 35. 9 | 79. 9 | |||
| Tensile Elongation(Break,%) | 350 | 250 | 2. 2 | 150 | 5. 4 | |||
| Physical Property | Specific Gravity (g/cm3) | 2.17 | 1.02 | 1.44 | 2.12 | 1.14 | ||
| Water Absorption 24hrs(%) | 0.00 | 1 | 0.06 | 0.00 | 0.1 | |||
| Water Absorption Saturation | <0.0 1 | 1. 60 | .2 | <0.01 | 3 | |||
| Service Application | Chemical & low temperature | High Pressure & Hydrocarbon | High pressure & temperature | Cryogenic | High Pressure & Hydrocarbon | |||
Sealing Material Application
| Type | HNBR | VITON | FFKM |
| Temperature Range ℉ | -40~302 | -4~392 | -4~620 |
| Temperature Range ℃ | -40~150 | -20~200 | -20~327 |
| Specific Gravity (g/cm3) | 1.34 | 1.85 | 2 |
| Hardness (shore A) | 75 | 75 | 75 |
