There is disclosed a method and apparatus for control of a power control loop. The filter walls have a working surface area through which air can pass during use, and the flange is a relatively rigid structure having an air inlet passing into the air permeable enclosure. Some embodiments also allow circulation of fluid as the casing is being run after the creation of the buoyant chamber. Each of the terminal locking tabs has a shape deflectable between an engaging position that locks each wire terminal and a disengaging position. A hook and loop fastener is used for connecting the ends of the belt together.