Ball Valve Seat & Seal Material Selection Guide
Ball valve seat and seal material specifications: hardness, temperature range, pressure rating, compressive strength for the soft seat ring: PTFE, RPTFE, PEEK, Nylon, Devlon, Molon, etc. Seal material: Viton AED etc.
Seat Material Specifictions
PTFE, RPTFE, Molon, PEEK
| PTFE | RPTFE | Molon(Nylon+MoS2) | PEEK | |
| Tensile Strength (MPa) | 24.8 | 25.4 | 75〜100 | 91 |
| Compressive Strength (MPa) | 35 | 52 | 100-140 | 137 |
| Elongation (%) | 250 | 120 | 10〜30 | 50 |
| Hardness(SH.A) | 56 | 60 | 78 | 82 |
| Water Absorption (%) | <0.01 | <0.01 | 0.7 | 0.12 |
| Specific Gravity (G/cm3) | 2.2 | 2.2 | 1.2 | 1.35 |
| Temperature Range (°F) | -300~400 | -150~425 | -40〜300 | -150~500 |
| Pressure Rating (Class) | 150~600 | 150~600 | 150~1500 | 150~2500 |
| Service Application | Chemical & Cryogenic | Chemical & Cryogenic | High Pressure & Lov/Temperature | High Pressure & High Temperature |
Seat Material Specifictions (continued)
Nylon, Devlon, Delrin
| Nylon 1010 | Nylon 12 | Devlon V | Delrin | |
| Tensile Strength (MPa) | 55 | 60 | 80 | 68 |
| Compressive Strength (MPa) | 70 | 79 | 140 | 110 |
| Elongation (%) | 150 | 200 | 5.37 | 220 |
| Hardness(SH.A) | 70 | 75 | 78 | 78 |
| Water Absorption (%) | 0.3 | 0.2 | 0.1 | 0.2 |
| Specific Gravity (G/cm3) | 1.04 | 1.01 | 1.14 | 1.41 |
| Temperature Range (*F) | -40〜200 | -58〜250 | -150〜300 | -58〜230 |
| Pressure Rating (Class) | 600〜1500 | 600〜1500 | 150〜1500 | 150-1500 |
| Service Application | High Pressures & Low Temperature | High Pressure & Low Temperature | High Pressure & Low/Temperature | High Pressure & Low Temperature |
Note: The soft seat is also called seat ring in floating ball valves; it is called seat insert in trunnion-mounted ball valves.
Seal Material Specifications
| Viton A | NBR | Viton B | HNBR(HSN) | Viton AED | |
| Temperature range (°F) | -20〜400 | -50〜250 | -20〜400 | -40〜320 | -20〜480 |
| Hardness (SH.A) | 70 | 70 | 70 | 80 | 90 |
| Specific Gravity (G/cm3) | 1.85 | 1.2 | 1.85 | 1.33 | 1.9 |
| Service Application | Petroleum Oils, Gasoline, Transmission Fluid | Petroleum Oils, Water, Hydraulic Oils | Mineral Acid, Steam, MTBE | Petroleum Oils, H2S&CO2 Anti-Explosive Decompression | Petroleum Oils, H2S&CO2 Anti-Explosive Decompression |
Gasket Material Specifications
| Flexible Graphite | Spiral Wound 316+Graphite | PTFE | SpiralWound Monel + PTFE | |
| Temperature Range °F | -300〜900 | -300〜900 | -300〜400 | -300〜400 |
| PH | 0〜14 | 0〜14 | 0〜14 | 0〜14 |
| Service Application | Fire-safe | Fire-safe | Cryogenic, High Corrosive | High Corrosive |
