Abstract: A fluid filter having a housing with an inlet and an outlet and a filter cartridge disposed in the housing and comprising a generally tubular filter element confined between endcaps at each end thereof. One end cap is closed and the other end cap has a nipple-like extension with an opening therethrough communicating the interior of the tubular filter with the outlet. The extension is telescopically received by a generally mating socket in the housing and is both axially and circumferentially sealed to the socket, with the circumferential sealing being maintained over a limited range of travel of the filter cartridge relative to the housing. A spring urges the extension toward the axially sealed condition in the socket and a perforated cylinder interposed between the one end cap and the housing precludes the filter cartridge from travelling a distance sufficient to break the circumferential seal between the extension and the socket in the event the flow of fluid through the filter is reversed.

Abstract: Electric discharge lamps of extended life can be produced or cheaper materials used in their manufacture by providing on the internal surface of the envelope and on the exposed surfaces of internal components a protective coating of a metal phosphate or arsenate glass. External surfaces can also be protected against corrosion in air or in the atmosphere within an outer jacket, where this is employed. The coating may be applied in a liquid medium which, preferably after draining, is warmed to evaporate the medium and thereafter baked to form the vitreous coating.

Abstract: Tungsten-halogen lamps of extended life are obtained by coating internal surfaces of the discharge tube and exposed surfaces of internal components with metal phosphate or arsenate glasses. The preferred glass is aluminium titanium phosphate. The coatings may be formed by applying a liquid composition capable of generating the desired phosphate or arsenate to the surfaces to be coated, and subsequently heating them to remove the liquid medium and form a vitreous coating. The medium may be water or an organic solvent such as an alcohol, and may contain a dissolved compound of the metal and an oxyacid of phosphorus or arsenic.