Abstract: An annular seal having a sealing member and method for use is provided for sealing an item of oilfield equipment. The annular seal has an inner diameter for receiving the item of oilfield equipment and a frame. The seal member is contiguous with the frame. The annular seal is configured for durability, in that it resists wear, inversion, increases lubricity, enables tightness, and/or otherwise generally increases endurance, toughness, and/or permanence.

Abstract: In a communication switching system including a control unit for establishing connections through a switching matrix, the connections being established during a cycle of the control unit and the cycle being divided into a number of sequence states or sub-cycles which established logical functions are to be accomplished before advancing to the next sequence state, an arrangement for making the sequencing of the control unit permissive instead of absolutely controlled by a timer set for worst case operation. With the disclosed arrangement, advance to the next sequence state is permitted as soon as all of the logical functions are accomplished. The control unit also can advance to the next sequence state if the worst case operating time is exceeded, and with a peg count of the occurrence being made.