Use of a sealing material which is a multifilament or spun yarn coated with a joint sealing composition to seal a joint in a pipe system in which system a fluid having corrosion inhibitors such as diammonium dimolybdate or benzotriazole; and/or sludge removers; and/or an alcohol such as propane diol, or ethylene glycol; and/or a hydrocarbon such as diesel, including biodiesel, fuel oil, or hydraulic oil; and/or steam at a temperature of at least 180° C. and a pressure of at least 10 bar (1000 kPa); is to be passed through the sealed joint. It is surprising that the sealing materials of the invention can maintain a sealed joint despite exposure to such materials.

Rubber compounds with increased resistance to fire are disclosed. The rubber compounds are incorporated into fire seals and in particular into fire seals for aerospace applications. The advance rubber compounds are created by adding a powdered vitreous or glass material in combination with a fiber such as carbon fiber, with or without intumescent material to a base rubber compound and then curing.

Rubber compounds with increased resistance to fire are disclosed. The rubber compounds are incorporated into fire seals and in particular into fire seals for aerospace applications. The advance rubber compounds are created by adding a powdered vitreous or glass material in combination with a fiber such as carbon fiber, with or without intumescent material to a base rubber compound and then curing.