Abstract: A heat exchanger leak detector employs a bubble detector to detect gas pressure build up in a heat exchanger second side from leakage of pressurized gas introduced in a heat exchanger first side.

Abstract: The ratchet buckle for tightening a strap under a ratchet action provides a lock to positively prevent the ratchet buckle from inadvertently releasing the strap. The lock requires a removable handle to be installed on the ratchet buckle before the lock can be released. The removable handle extends the ratchet buckle crank arm for increased leverage in exercising the ratchet buckle and when removed reduces the overall size of the ratchet buckle and eliminates a crank arm portion that would otherwise extend beyond the ratchet buckle base.

Abstract: An improved fish passage apparatus is combined with hydroelectric power generation to facilitate migration of fish between water bodies of different heights with minimal injury or trauma to fish. It may also be optimized for power generation when fish are not moving through it. The fish passage apparatus comprises a connecting tube providing fluid communication between upper and lower water bodies, an upper valve in the connecting tube adapted to control flow of water to or from an upper water body, a lower valve in the connecting tube adapted to control flow of water to or from a lower water body, and a working tube opening into the connecting tube between the upper and lower valves a working portion of which extends functionally vertical to above a water level of the upper body of water and to below a water level of the lower body and is vented at its top such that water can flow freely in and out of the working portion.

Abstract: This device for encasing light strings for storage provides a canister as a handle that is concentric with a cylindrical feed tube that is at least partially within the canister together with a cartridge type removable dispensing tube that slides over the feed tube and within the canister. The canister is attached to the large end of a funnel on the feed tube entry end through which a light string may be fed. The canister and feed tube thus form an annular slot into which the removable cartridge type dispensing tube may be received and releasably secured slidably over the feed tube. The tubular plastic is loaded on the dispensing tube prior to the dispensing tube being slid and secured over the feed tube.