Abstract: A concrete pumping pipe coupling operates at nominal pressures of 2,000 psi and momentary peaks in excess of 3,000 psi. A two-piece hinged coupling forms a cylindrical enclosure encircling adjacent pipe ends. A two-piece latch releasably interconnects the ends of the two coupling sections. The latch includes a lever pivotally mounted to a link which is pivotally connected to the one coupling section. The lever pivots on a cam member connected to the other coupling section. The link includes a bolt threaded into an elongated nut. The threaded connection is for varying the length of the link. The elongated nut has an annular inner groove with a stop wall at each end. A spring-loaded limit pin is slidably mounted in a blind hole in the bolt and projects into the recess. The stop walls in the nut limits the movement of the bolt from the nut and thereby the extension of the link.