Abstract: The invention provides an uncomplicated ball check valve whose components can be economically manufactured, assembled and connected and wherein, in accordance with one aspect of the invention, the ball check valve is configured for use as a pressure vessel. In one embodiment of the invention, the ball check valve comprises a housing defining one or more inlet, an outlet and a passageway therebetween. A ball support system is mounted within the housing, wherein one or more balls are supported by the ball support system. The ball support system is configured to allow a ball to close off and open a respective inlet. The housing generally comprises an inlet section which can have one or more inlets, wherein each inlet defines a ball seat sealingly engageable with a ball for sealing the inlet. The housing further comprises a centre section providing adequate space to allow movement of the ball and an outlet section comprising an outlet for transferring the fluid to a subsequent portion of a piping network.

Abstract: The invention relates to compositions useful for prolonging the action and increasing the selectivity of herbicide compositions containing .alpha.-chloroacetamide derivatives as active ingredient as well as to highly selective herbicide compositions containing .alpha.-chloroacetamide derivatives as active ingredients and optionally an antidote wherein an animal derivative of the general formula (III) is used for achieving the prolonged action and increased selectivity. In the formula (III) ##STR1## R.sub.5, R.sub.6, R.sub.7 and R.sub.8 stand independently for hydrogen, a C.sub.1-6 alkyl, C.sub.3-7 cycloalkyl or C.sub.2-5 alkenyl group optionally substituted by a C.sub.1-4 alkyl group; andR.sub.9 stands for hydrogen or a C.sub.1-4 alkyl group optionally substituted by halogen, or a phenyl group.

Abstract: Process for the preparation of alkali-poor .alpha.-alumina for ceramic purposes. Technical grade aluminum hydroxide is activated and calcinated in the presence of a mineralizing mixture comprising halides and boron compounds. The process further comprises activating aluminum hydroxide at a temperature of 500-600 degrees C., washing the activated product with alkali-free water containing calcium ions and having a conductivity not exceeding 70 .mu.S/cm until the alkali content expressed in Na.sub.2 O becomes lower than 0.15% by weight, adding 0.4-0.7% by weight of a mineralizing mixture to the washed product, and calcinating the same at a temperature of 1200-1350 degrees C.

Abstract: A simplified linkage and cam member having first and second cam surfaces for interacting with a bail to drive said bail between first and second limits is provided. The cam surfaces restrict the movement of the bail when the bail is at either limit. However, when the bail is intermediate of the limits, the relationship of the effective portions of the cam surfaces allow increased bail movement for a given position of the cam member and associated cam surfaces. The structure is particularly well adapted for actuating a bail from a first to a second position wherein forces other than those applied by the cam also act on the bail; and at a critical bail position, the other forces take control and urge continued motion of the bail independent of the cam member.

Abstract: When electrical equipment is used in a hazardous atmosphere, it must be enclosed in an explosion proof enclosure so an electrical spark cannot cause a fire or explosion. The present invention provides a means for assuring that an explosion proof enclosure which has been opened for inspection, repair or adjustment of the electrical apparatus is restored to its original condition. To this end, a visually inspectable locking means is provided. The locking means can be engaged only when the enclosure compartment and its associated cover are restored to their original explosion proof relationship. The locking means does not exert any distorting force on the mating threads of the enclosure.