The Apollo Valve 61LF series Ball Cone check valve is a lead-free inline valve. 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. Reinforced polytetrafluoroethylene (RPTFE) Ball Cone provides higher chemical resistance. It has female National Pipe Taper (NPT) threads for connecting to male threaded pipes, creating a tighter seal than straight threads. The maximum pressure rating is 400 pounds per square inch (psi), and the maximum steam pressure is 125 psi. The maximum temperature is 350 degrees Fahrenheit. This valve is lead free and complies with California's AB 1953 law for safe drinking water. 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. Apollo Valves manufactures ball, mixing, and relief valves, actuators, water gauges, marine fittings, heating and plumbing products, and backflow prevention. The company, founded in 1928 and headquartered in Matthews, NC, meets international standard International Organization for Standardization (ISO)/IEC 17025:2005 and makes products that meet International Organization for Standardization (ISO) and American National Standards Institute (ANSI) standards.