Apollo® CVB-LF (61LF Series) Ball Cone® check valves offer reliable protection against reverse flow and exceptional resistance to chemicals and corrosion using proven ASTM grade lead free* materials. They are well-suited for a broad range of applications, including saturated steam and chemical service. They may be installed in both horizontal and vertical orientation with upward flow. Proudly made in the USA. Bubble-tight shut-off, ideally suited for gaseous service. Straight-through flow minimizes pressure loss. 1/2 psi cracking pressure.