70 Shore A High-Temperature Silicone Rubber Gasket (Up to 300°C)
This product is a large-diameter circular static sealing gasket made from silicone rubber with 70 Shore A hardness, designed for covers, clamping frames, and flange faces that require reliable sealing against hot air, hot water, steam/heat loss, and process gases in high-temperature environments. Anh Trí Tuệ (ATT) manufactures these gaskets based on customer samples or specifications to ensure correct fit, proper sealing contact, and stable performance in operation.
1) Main Functions in Assembly
Large circular silicone gaskets are typically used to:
- Seal the joint between a cover and a tank body, access door frame, or equipment cover, minimizing leakage along a large circumference.
- Provide an elastic cushion to compensate for surface deviations (flatness, concentricity, surface roughness), reducing the risk of localized leaks.
- Reduce heat loss and help prevent dust/contaminants from entering at positions that are periodically opened for inspection and cleaning.
2) Why Choose 70 Shore A Silicone for High-Temperature Service
Silicone is widely used for heat-sealing applications thanks to its elasticity retention at elevated temperatures and good stability under dry heat conditions. A 70 Shore A hardness is commonly selected because it offers:
- Sufficient compliance to conform to mating surfaces and create a tight seal under clamping/bolt load.
- Adequate shape stability to resist excessive collapse/flattening during long-term compression.
- Good suitability for bolted covers and clamp-type assemblies where consistent, controllable tightening force is required.
Technical note: Actual temperature performance depends on thermal cycle (continuous vs. intermittent), compression level, and the working media. For special media (solvents, oils/hydrocarbons, aggressive chemicals, or high-pressure steam), material compatibility should be verified before long-term operation.
3) Typical Market Applications (by Equipment Group)
- Tank access doors and inspection covers in processing plants: storage tanks, mixing tanks, buffer tanks, heating tanks—locations requiring frequent opening for cleaning/inspection while maintaining reliable sealing during operation.
- Heated process equipment covers: positions exposed to hot air, process gases, or circulating hot water (depending on operating conditions) where stable static sealing on a large circumference is needed.
- Industrial drying/heating equipment: door/cover sealing pads to reduce heat loss, prevent air leakage, and stabilize temperature within heated zones.
4) Installation Notes for Better Sealing and Longer Service Life
For large-diameter gaskets, sealing performance strongly depends on tightening method and compression:
- Tighten evenly around the circumference using a star/cross pattern and multiple passes to distribute load uniformly.
- Avoid tightening heavily on one side first, which can tilt the cover and cause localized leakage at 1–2 points along the circumference.
- Ensure mating surfaces are clean and free of burrs/sharp edges to prevent cutting the gasket during tightening.
- If there are large heat-up/cool-down cycles, re-check sealing after the first operating cycle (when the process allows).
5) ATT Custom Manufacturing Capability
ATT produces silicone gaskets to sample or specification for both single pieces and production quantities:
- Accurate profile manufacturing based on the actual sample to ensure proper fit and correct sealing contact.
- Optional hardness (Shore A) and color selection for identification or internal customer standards.
- Practical installation-oriented support: recommendations on thickness, hardness, and tightening approach to improve sealing and optimize service life.
Reference Sizes (For Size Range Illustration Only; ATT Manufactures to Sample)
- Current reference sample: ID695 × OD709 × thickness 22 mm
- Common tank access/inspection size range (reference only; varies by tank/cover design):
- ID ~457 mm, OD ~610 mm (18")
- ID ~508 mm, OD ~660 mm (20")
- ID ~610 mm, OD ~762 mm (24")
- ID ~762 mm, OD ~914 mm (30")
- ID ~927 mm, OD ~1067 mm (36-1/2")
- Some configurations use larger OD depending on flange/cover style
- Reference thickness range by assembly design:
- 3–5 mm: flat sheet-cut gasket (common for flat flange faces)
- 10–25 mm: thick gasket for grooves/clamping frames, better for compensating misalignment and improving sealing (typically custom-made to sample)
