In high-pressure pumping applications, there are many situations where high velocity and erosive fluid needs to be throttled through a partially open plug valve. Bleeding of frac lines and controlling cement flow are two such situations. Neither quarter-turn plug valves nor standard chokes are designed for such applications. Quarter-turn plug valves are not designed to handle throttled flow conditions without causing significant body wear and early demise of the valve. Standard adjustable chokes cannot survive erosive flows without causing a loss of seal-tight shutoff capability.
FMC Technologies’ Flowline Choke Throttle Valve is a new concept in choke valves. The best attributes of a ported cage choke and a plug valve are combined in this valve. The choke portion of the valve is used to throttle high velocity flows while the plug valve portion of the valve remains fully open. The plug valve portion of the valve is protected by the choke from high velocity erosive flow. Because of the combined use of the two halves of the valve, high velocity erosive flows can be throttled without degrading the positive shutoff performance of the valve.