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Figure 6.21 – Vetco uniflex joint cross section. (Courtesy Vetco)

The drilling riser joints may be connected by any number of means,

including welding, threading, snap rings, segmented locking dogs, and bolted

flanges. The requirements for fast makeup and disconnect, rigid pressure- tight

connections, minimal stress variance, compactness and light weight for minimum

tensioning and buoyancy needs, and easy maintenance must all be considered.

Usually, the female (box) portion contains dogs or ring segments, actuated by

bolts, that clamp into grooves machined into the male (pin) member of the

connector. The connectors are welded on the ends of each riser joint so the riser

may be run similarly to drill pipe by stabbing one joint at a time and tightening the

connector. A marine riser connector provides the crossover from the flex joint to

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