National Coupling Company ( NCC ) is located in Stafford, Texas, southwest of downtown Houston. Founded in 1968, NCC began its business manufacturing commodity air coupling products for industrial applications. As oil and gas exploration accelerated in the 1970's, NCC developed and introduced a new line of elastomer seal hydraulic couplings specifically designed for subsea blowout preventer ( BOP ) control system applications. National Coupling Company was acquired by Hunting PLC in June of 2009.In the early 1980's, subsea oil and gas production systems were being developed requiring high reliability subsea components including hydraulic couplings. In response to this emerging need, NCC developed a metal-to-metal seal hydraulic coupling and was awarded its first patent in 1987. Today, with more than 40 years of coupling design and manufacturing experience and more than 300 U.S. and Foreign patents granted, NCC is still producing hydraulic couplings for the most critical applications including extreme high pressure/high temperature ( XHPHT ) designs up to 22, 500 psi and 350 F ( 177 C ).As part of NCC's diversification strategy, the Company introduced a new and revolutionary Chemical Injection System design for subsea applications in 2006. The system utilizes positive displacement metering to provide precise control and verification of chemical injection rates without the use of flow meters. Continuing the diversification strategy, NCC introduced a new line of Specialty Valve products that includes a subsea Chemical Injection Back Pressure Valve, control valves for deep water BOP control systems and other special purpose directional control valves.