

Application
Properties
Application
- Sealmax Style 940D – Diffusion barrier envelope is a multi-layer PTFE envelope gasket designed to prevent chemical diffusion, permeation and wicking into the gasket core.
- The construction incorporates an additional high-density PTFE diffusion barrier layer, offering superior sealing integrity compared to standard PTFE envelope gasket.
- Style 940D is widely use in applications like highly aggressive and permeating chemical media, vacuum and pressure services, toxic, hazardous or high-purity processes.
- It is used in industries like Chemical, Pharma, Petrochemical, Fertilizer, Food & Beverages
Properties
- Excellent chemical resistance.
- Very low permeability
- Prevents core contamination and media attack
- Non-stick, low friction surface
- Long service life.
- Food Grade
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Technical Specifications
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SR.NO.
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PROPERTIES
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UNIT
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Test Method Reference
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Specified Values
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1.
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Density
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gm/cm3
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ASTM D-792
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2.15 – 2.30
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2.
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Tensile Strength (Min.)
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Mpa
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ASTMD-638
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20 – 30
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3.
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Hardness
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–
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Shore D
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60
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4.
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pH range
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–
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–
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0- 14
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5.
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Maintenance factor (m)
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–
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–
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2.5
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6.
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Seating stress (y)
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–
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–
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1800 psi
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General Specifications
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SR.NO.
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Parameters
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Specifications
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Remarks
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1.
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Material
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100% Virgin PTFE
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–
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2.
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Colour
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White
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–
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3.
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Operating Temperature
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Max 260⁰ C
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–
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4.
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Pressure range
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Upto 60 bar
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Depends on insert and service conditions
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5.
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Size range
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DN 15 to DN 600 and above
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Customized sizes on request
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6.
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Available forms
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Slit Type, Mill Type and Fused Type
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–
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7.
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Available thickness
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0.5mm to 6.0mm
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Customized on requests
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8.
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Available inserts
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CNAF, Rubber, Graphite, SS corrugated
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Customized insert on request
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