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USA Gylon 3500 Gasket
QS Gasket: USA Gylon 3500 Gasket
Name: USA Gylon 3500 Gasket
Standard: ASME B16.5
Material: Gylon 3500
Temperature: -268℃ to 260℃
Size: 4 Inch
Pressure: 150LB
Complete Set: with G10 Sleeve and Washers and ZPS
Compound: with High-performance modified polytetrafluoroethylene
Standard: ASME B16.5
Material: Gylon 3500
Temperature: -268℃ to 260℃
Size: 4 Inch
Pressure: 150LB
Complete Set: with G10 Sleeve and Washers and ZPS
Compound: with High-performance modified polytetrafluoroethylene
Quantity
USA Gylon 3500 Gasket, fully conforming to ASME B16.5, rated for –268 °C to +260 °C.
Standard package includes G10 insulating sleeves & washers plus ZPS metal parts, delivering a complete bolt-up kit.
4-inch 150 LB size ex-stock; excellent chemical inertness for strongly corrosive, high-vacuum and cryogenic flange duties; long life, easy install—the safe choice for premium piping in petrochemical, LNG and semiconductor plants.
Standard package includes G10 insulating sleeves & washers plus ZPS metal parts, delivering a complete bolt-up kit.
4-inch 150 LB size ex-stock; excellent chemical inertness for strongly corrosive, high-vacuum and cryogenic flange duties; long life, easy install—the safe choice for premium piping in petrochemical, LNG and semiconductor plants.
How do we select the right insulating gasket?
After fifteen years on the supply side we break the job into five steps—“electrical, temperature, medium, pressure, life”.
Follow the sequence and you will rarely be wrong; this is the same logic proved in petrochemical plants world-wide with USA Gylon 3500 Gasket.
After fifteen years on the supply side we break the job into five steps—“electrical, temperature, medium, pressure, life”.
Follow the sequence and you will rarely be wrong; this is the same logic proved in petrochemical plants world-wide with USA Gylon 3500 Gasket.
1. Fix the electrical rating
Look up the required breakdown voltage and volume resistivity.
-< 1 kV low voltage: epoxy-glass cloth (FR4/G10/G11) is cheapest.
- 1–30 kV medium voltage: choose modified PTFE (Gylon 3504/3505) or mica-filled PTFE.
- > 30 kV high voltage / lightning surge: virgin PTFE + metal-oxide filler, or laminated mica board.
Compare both dry and wet values—many field failures happen after rain.
Look up the required breakdown voltage and volume resistivity.
-< 1 kV low voltage: epoxy-glass cloth (FR4/G10/G11) is cheapest.
- 1–30 kV medium voltage: choose modified PTFE (Gylon 3504/3505) or mica-filled PTFE.
- > 30 kV high voltage / lightning surge: virgin PTFE + metal-oxide filler, or laminated mica board.
Compare both dry and wet values—many field failures happen after rain.
2. Fix the temperature
Draw a red line at “actual maximum temperature + 20 °C”:
- –268 °C … +260 °C: Gylon 3500 and modified PTFE cover the whole span.
- +260 … +330 °C: switch to glass-filled PTFE or G11.
- > 330 °C: move to mica / ceramic-fiber gaskets such as THERMa-PUR or Phlogopite grades.
Draw a red line at “actual maximum temperature + 20 °C”:
- –268 °C … +260 °C: Gylon 3500 and modified PTFE cover the whole span.
- +260 … +330 °C: switch to glass-filled PTFE or G11.
- > 330 °C: move to mica / ceramic-fiber gaskets such as THERMa-PUR or Phlogopite grades.
3. Fix the medium
List “acids, alkalis, solvents, oil, water, chloride, H₂S” and tick the boxes.
- Strong oxidising acids (conc. nitric, oleum): only virgin or modified PTFE may be used.
- Hydrofluoric acid, hot caustic: virgin PTFE is attacked; use Gylon 3510 (silica-filled) or mica board.
- Chloride > 100 ppm: add PTFE envelope on the gasket OD to prevent pitting of stainless-steel flanges.
List “acids, alkalis, solvents, oil, water, chloride, H₂S” and tick the boxes.
- Strong oxidising acids (conc. nitric, oleum): only virgin or modified PTFE may be used.
- Hydrofluoric acid, hot caustic: virgin PTFE is attacked; use Gylon 3510 (silica-filled) or mica board.
- Chloride > 100 ppm: add PTFE envelope on the gasket OD to prevent pitting of stainless-steel flanges.
4. Fix the pressure
Convert flange class to “maximum surface pressure”:
- 150 LB ≈ 20 bar → modified-PTFE 3500 series, surface pressure ≤ 55 MPa is fine.
- 600 LB and above or RTJ face: add G10 insulating sleeves + metal reinforcement ring to stop creep.
Look up gasket factors m and y and run the ASME VIII calculation—don’t rely on rule-of-thumb alone.
Convert flange class to “maximum surface pressure”:
- 150 LB ≈ 20 bar → modified-PTFE 3500 series, surface pressure ≤ 55 MPa is fine.
- 600 LB and above or RTJ face: add G10 insulating sleeves + metal reinforcement ring to stop creep.
Look up gasket factors m and y and run the ASME VIII calculation—don’t rely on rule-of-thumb alone.
5. Fix the life
- Frequent thermal cycles (≥ 3 per day): pick “micro-porous PTFE” or “expanded PTFE” for better recovery.
- Ten-year no-touch service: use USA Gylon 3500 Gasket with G10 sleeves + ZPS metal parts; preload loss < 10 %.
- Removable for quick maintenance: choose “single-side centre-locating tab” design; next gasket change takes 30 s.
- Frequent thermal cycles (≥ 3 per day): pick “micro-porous PTFE” or “expanded PTFE” for better recovery.
- Ten-year no-touch service: use USA Gylon 3500 Gasket with G10 sleeves + ZPS metal parts; preload loss < 10 %.
- Removable for quick maintenance: choose “single-side centre-locating tab” design; next gasket change takes 30 s.
Three field reminders
1. Flange roughness Ra 3.2 µm is the upper limit; rougher finishes will “chew” the PTFE edge.
2. Bolt preload must be applied with a torque wrench in three passes; modified PTFE has a low modulus—over-torquing equals a wasted joint.
3. Measure thickness tolerance on stored gaskets; PTFE sheet grows ~1 % per year; an 0.2 mm oversize can leak.
1. Flange roughness Ra 3.2 µm is the upper limit; rougher finishes will “chew” the PTFE edge.
2. Bolt preload must be applied with a torque wrench in three passes; modified PTFE has a low modulus—over-torquing equals a wasted joint.
3. Measure thickness tolerance on stored gaskets; PTFE sheet grows ~1 % per year; an 0.2 mm oversize can leak.
Summary
Set the three red lines—electrical + temperature + medium—first; then pick thickness by pressure and configuration by life; finally lock down the three details—flange roughness, bolt torque and shelf age—and USA Gylon 3500 Gasket will never “pop” in the plant, keeping your piping safe and economical.
Set the three red lines—electrical + temperature + medium—first; then pick thickness by pressure and configuration by life; finally lock down the three details—flange roughness, bolt torque and shelf age—and USA Gylon 3500 Gasket will never “pop” in the plant, keeping your piping safe and economical.
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