valve mechanism that controls opposed directional movement of a piston connected to a punch of the perforator apparatus application_number US 98294701 A description with reference to fig1 of the drawings a coiled tubing anchor assembly designated as 10 is activated by internal liquid pressure specifically within the housing 12 of this assembly there is provided a piston 14 and anchoring slips 16 having serrations 18 on the outer surface thereof by applying a selected pressure to the piston 14 within the housing 12 the piston moves linearly to cause the slips 16 to move radially into contact with the wall of the tubing not shown the serrations 18 with the slip in this position anchor the device to the tubing this permits accuracy of punching by the associated punch mechanism upon completion of this operation the coiled tubing pressure is reduced and the slips are then free to retract away from the tubing wall and thus release the anchor assembly and associated toolstring components so that the toolstring components may be moved to a new location within the well bore the operation may then be repeated to permit anchoring for an additional punching operation the hydraulic anchor assembly 10 is connected to a hydraulic control valve designated generally as 20 the hydraulic control valve 20 includes a housing 22 within which is provided a velocity flow valve 24 and a check valve 26 also within the housing there is provided an annular passage 27 that provides fluid flow to side 30 of a piston 32 likewise a central passage 34 provides for fluid flow to the opposite side 36 of the piston 32 at a controlled flow rate pressure differential the velocity flow valve 24 is open and flow is directed.