... for furniture, micro-pumps for sprays, dispensers, pumps and valves, precision instruments, measurement and control equipment, photographic and ... chlorates. Nylon Balls (Zytel®, Polymide,PA)is used in check valves, light load bearings, knobs and toggle switches and other ... that provides a good seal at low pressure in non return valves and excellent wear resistance. Polyurethane is not recommended ...