Surgical Scrub Sink NSN 6545-01-117-3894. Modification and Evaluation

摘要

The surgical scrub sink was developed to provide a facility for scrubbing at field hospitals. Complaints were received stating that the sink used too high a volume of water, so a manifold with small inner diameter was installed at the pump outlet post to restrict flow. The restriction forced the pump to operate against increasingly high back pressures. Consequently, the water pump frequently overheated and required replacement of prematurely worn parts. A fan assembly was added to aid in cooling the pump motor, but excessive wear was still evident. The sink design was reevaluated in 1985. It was proposed that a pressure relief valve be added at the pump outlet to reduce back pressure, therefore, reducing operating temperature and component wear. This modification was tested to evaluate the concept and determine the subsequent necessity of continuing the fan modification. The sink was operated at minimum and maximum flow rates, with and without the fan, in an environmental chamber with varied ambient temperature. It was found that a brass pressure relief valve cracking at approximately 5 lb/sq. in. with pipe size 1/2 inch supplied the sink with enough pressure to maintain flow rates while reducing back pressure enough to allow the pump to efficiently operate and kept the pump from overheating. Additional testing showed that the extra fan was required in rooms with poor circulation.