Pipeline flow restrictor

A pipeline fluid flow restrictor cartidge for insertion through a hole in the pipeline side wall comprising;

• a substantially circular rear end plug, a substantially circular front end plug, a cylindrical radially expandable flexible sleeve having an opening in the central portion of one end and attached in substantially fluid-tight relation to the periphery of said rear end plug at said opening and said front end plug at the opposite end, said rear end plug having a through flow passage having an interior opening in the interior face of said rear end plug in communication with the interior portion of said flexible sleeve and an opposite exterior opening in the exterior face of said rear end plug adapted for communication with supply means providing fluid for inflating said flexible sleeve, said exterior face of said rear end plug having attachment means for engagement with mating attachment means of an insertion assembly, said flow restrictor cartridge having an overall deflated diameter about 20 to 50 percent the inside diameter of the pipeline in which it is to be used, said flow restrictor cartridge having sleeve retainer arm sockets in the periphery of at least one of said end plugs and sleeve tetainer arms pivotally mounted in said sockets, said retainer arms being of suitable length to pivot outwardly against the interior wall of said pipeline at an angle of about 40.degree. to about 60.degree. with the axis of said flow restrictor cartridge, thereby restricting axial expansion of said flexible sleeve upon its inflation.