This Control Devices in-tank check valve is a poppet-type valve, and may be disassembled for cleaning or repair The valve body is made of brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability. Brass can be connected to copper, brass, plastic, aluminum, and welded steel. This valve has a glass-filled polytetrafluoroethylene (PTFE) poppet with eight discharge holes for quiet operation, and stainless steel spring. It has a compression connection on one end for a leak-proof connection without the need for additional joining preparations, and female NPT threads end on the other for connecting to male threaded pipes, creating a tighter seal than straight threads. The maximum pressure rating is 450 pounds per square inch (psi), and the maximum working temperature is 400 degrees Fahrenheit.Check valves have two ports and restrict the flow of fluids and other loose materials through a pipe or passageway to one direction. Flow enters through one port and exits through the other, closing when flow reverses or stops. Two common types of check valves are ball cone valves and swing check valves. A ball cone valve utilizes a spring-loaded ball seated against a cone-shaped interior surface to stop the flow of fluid in a forward direction, and a swing check valve has a movable disc on a hinge to block reverse flow. Check valves are rated by their cracking pressure (the minimum upstream pressure required for the valve to operate), and they are used in various water, gas, air, and steam lines.Control Devices manufactures specialty valves, nozzles, and condensate traps. The company, founded in 1963 and headquartered in Fenton, MI, meets ASME standards.