Anver Corp. (Hudson, Mass.) has introduced the Anver CheckVac line of leak-proof vacuum check valves. The one-way valve design features a one-piece aluminum body and a check element with a softer spring than those typically found in compressed-air system check valves. This new check valve reportedly minimizes the loss of flow because less of the pump’s power is expended to depress the softer spring. The valves are available in 0.25-inch to 2-inch (0.25-inch to 2-inch) NPT sizes.