Thermiculite™ 894 is a flexible gasket material, based upon the proprietary Thermiculite™ sealing material used in the Thermiculite™ critical service series of products and has all of the performance capability of that series.
It is made by over-knitting strips of foil used in the manufacture of Thermiculite™ 835 spiral wound gaskets with a fine (0.09mm diameter) Inconel 600 wire and then braiding a number of those Thermiculite™/ Inconel strips to produce a square section sealing material available in continuous coil form.
Thermiculite™ 894 is intended for service in applications where an asbestos rope or plaited asbestos packing would previously have been used. Such applications include the manufacture of nitric acid and ammonium nitrate fertilizer. It can also be used for on–off , or isolation, valve stem sealing or as the header rings either side of a conventional valve stem sealing stack. In the latter instance it may be beneficial for the Thermiculite™ 894 to be of a lower than standard weight per unit length so that valve stem friction is minimised: lower weight per unit length material is available to special order.
• pH Range: 0 To 14
• Temperature Limit: 1050°C (1920°F)
• The following square section material is available in coils: 6.0mm, 9.5mm, 12.5mm and 19.0mm
• Rectangular cross-sections are possible
Health and Safety
The product is believed to present no health and safety hazard and, under normal handling and use it is unlikely that the product will give rise to significant levels of exposure to constituent materials.
Thermiculite™ 894 contains vermiculite, steatite, Inconel wire and a small percentage of nitrile rubber.
Under harsh mechanical treatment (e.g. abrasion) or if the product has become friable by high temperature applications, the constituents may give rise to irritant dust which, in extreme cases of exposure, could lead to more serious respiratory problems. Occupational exposure to such dusts should therefore be minimised and kept below relevant national exposure limits.
Good standards of hygiene should be applied during cutting, installation and removal and any residues should be disposed of by transfer to a site appropriately licensed to accept industrial materials of this nature.
Although vermiculite and steatite are non-fl ammable at elevated temperatures or in a sustained fire, decomposition of the small percentage of rubber binder will occur and give rise to irritant and in some instances harmful or toxic fumes.