Profile: Cook Manley is a source for advanced, engineered products that improve the efficiency, reliability and economy of reciprocating compressors and natural gas engines. We offer products like compressor valve, CMll air compressor valves, thermoplastic replacement parts, capacity controllers, HSR high-security valve restraint systems and cartridge-style fuel gas injector valves. Aerodynamic flow reduces the resistance incurred by the gas as it passes through the valve.