Abstract: A backflow prevention apparatus has a housing with an opening having a predetermined length. A first valve body, and a second valve body may be slidably sealed with one another, and compressed such that their combined length is less then the length of the opening. In the compressed state the valve bodies may be inserted within the opening of the housing and then elongated such that the ends of valve bodies engage and sliding seal with segments of the housing. A spacer may be placed between the first valve body and the second valve body to secure them within the opening. An intermediate valve body may be introduced between the first valve body and the second valve body.

Abstract: A system and method for controlling, monitoring and integrating engineering and manufacturing changes in a manufacturing enterprise. The status of an engineering change and the status of items affected by the engineering change are monitored by an engineering change control manager application running at a central data processing facility. The engineering change and design or modification of items affected by the change are released to one or more manufacturing locations where additional design changes may be made to accommodate local manufacturing capabilities. Each manufacturing location accepts the engineering change and the corresponding affected items when ready to proceed with implementation of the engineering change. The affected items are promoted locally at the manufacturing location to effective status which releases the affected items into production at the plant.