A choke valve for use on water injection wells is disclosed. The valve comprises a body, a sliding sleeve, in the body, a boss shaped plug, and a means for urging the sliding sleeve against the plug. The fluid path through the valve is largely straight, reducing wear on the valve, and the valve is devoid...http://www.google.sh/patents/US4825895?utm_source=gb-gplus-sharePatent US4825895 - Water injection choke valve
