The automatic spring-fed knives feature of this tool prevents excessive strain from being applied from the rig floor that could cause the knives to burn or break before the cut is completed. The Logan Standard External Cutter consists of a top sub, body, guide, knives, spring dog assembly, thrust washer, thrust bearing, preload sleeve, feed ring, main spring, and shear pins.
Logan Internal Cutters are used to cut tubing, casing, and drill pipe and may also be run on sucker rods and macaroni strings. These mechanically operated cutters permit alternate sizes of pipe to be cut when redressing an assembly. All Internal Cutters feature a device that allows the operator to set the cutter to any depth, release the tool, and reset it to another depth without coming out of the hole. Each cutter is designed to cut a given range of tubing when dressed with correctly sized components. Collar finders are also available for each size.
The Logan Internal Pressure Pipe Cutter utilizes pump pressure to actuate three carbide-coated knives to cut single and multiple strings of pipe from 4 inches OD to 36 inches OD. Each different size cutter can be dressed with different lengths of knives to cut different sizes of pipe. Pump pressure is preset by a simple adjustment so the knives will extend at the exact desired diameter. Flow restriction across an orifice feeds a piston that forces the knives out. When the knives reach a preset diameter, the operator will see a sudden pressure drop that indicates that the pipe has been cut.
These quick, smooth operating Logan External Cutters allow for fast recovery of tubing or drill pipe. A hydraulically fed piston forces the knives of this cutter into the pipe to give the operator sensitive cutting control. The tool consists of a top sub, segmented piston assembly, knives, knife pins, guide screw, body, and guide.