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Special high-pressure gasket material for highest thermal and mechanical stresses

KLINGERSIL® C-4509 is a special high-pressure gasket material that offers excellent service in many sectors of the chemical industry. Main fields of application: alkaline media and steam. The expanded metal reinforcement is a galvanized low carbon steel insert which increases the compressive strength and pressure capability. Suitable for high-pressure applications because of its higher resistance against blowouts.

This material is manufactured with carbon fibers and special high-temperature resistance additives and reinforced with a nitrile binder.


Typical Values Refer to 1/16" Thick Material Unless Noted

Creep relaxation ASTM F38B (1/32") 20 %
Compressibility ASTM F36J (1/32") 8 - 14 %
Recovery ASTM F36J 50 % minimum
KLINGER Hot Compression Test
Thickness Decrease 73°F (23°C)
Thickness Decrease 572°F (23°C)

10 % initial
8 % additional
Weight increase ASTM F146 after immersion in
Fuel B, 5h/73°F (23°C)

10 % maximum
Thickness Increase ASTM F146 after immersion in
ASTM Oil IRM 901, 5h/300°F (149°C)
ASTM Oil IRM 903, 5h/300°F (149°C)
ASTM Fuel A, 5h/73°F (23°C)
ASTM Fuel B, 5h/73°F (23°C)

0 - 5 %
0 - 3 %
0 - 5 %
0 - 5 %
Density ASTM F1315 125 lb/ft ³ (2.0 g/cc ³)
ASTM F104 Line Call Out F712112B3E11M8
Color Black


The pressure/temperature graphs shown are the most current method of determining the suitability of a gasket material in a known environment. However, chemical compatibility must also be considered.
pT diagram for thickness 1/16":
C-4509 Liquid
C-4509 Gasses and Liquids
In area 1 the gasket material is suitable using common installment practices subject to chemical compatibility

In area 2 appropriate measures are necessary for installation of the gasket to ensure maximum performance. Please call or refer to KLINGERexpert for assistance.

In area 3 do not install gaskets in these applications without first referring to KLINGERexpert or contacting KLINGER Thermoseal's technical support service.
The ability of a gasket to make and maintain a seal depends not only on the style and quality of the gasket material, but also on medium being sealed, the flange design, the amount of pressure applied to the gasket by the bolts and how the gasket is assembled onto the flanges and tightened. These factors are beyond the manufacturer's control. Please take note of our installation manual in TECHNICAL RESOURCES.