A cutter member for use in cutting a hole in plastic pipe having a thick wall or a thin wall. The cutter member is rotated and advanced with a positive predetermined lead against the pipe, the cutter member being so designed that after it has cut the initial chips off the outside curvature of the pipe, it cuts a continuous chip by a peeling action and the initial chips and continuous chip are discharged inwardly of the cutter member above the coupon being cut. The cutter member may be repeatedly used and it can be used with a drilling tool or machine or, for that matter, a tapping tee. The preferable drilling machine for use with the cutter machine is of simple construction, including a tubular body member, a two-piece boring bar with one member having threads thereon for positively advancing the cutter member, and the other member of the boring bar being adapted to receive the cutter member. The drilling tool is detachably attached to a pipe or to a fitting operatively connected to the pipe, the fitting having the usual passageway therethrough and the boring bar being arranged to extend through the passageway to the wall of the pipe to be cut. The drilling tool is provided with means where the boring bar can be rapidly advanced to the cutting position or rapidly retracted after cutting and, further, the drilling tool is designed to prevent blow out of the boring bar when cutting pipes under pressure.
A tool for tapping from a branch pipe into a main pipe to establish communication between the pipes. The tool has a bit for cutting a hole in the main pipe which is secured to an upstream end of a shaft for transmitting torque to the bit. The tool has a branch-engaging member engaged to the branch pipe adjacent to the downstream end of the branch pipe. The shaft has a threaded section engageable with a threaded section of the branch-engaging member so that as the shaft is rotated, the bit is driven along the longitudinal axis of the branch pipe toward the main pipe.
An apparatus for cutting into and stopping the flow of fluid in a plastic pipe including a cutting blade that is forced downwardly into a pipe by a hydraulic force. The blade is slightly larger than the internal diameter of the pipe and thus when located within the pipe stops the flow of fluid in the pipe. The apparatus is constructed so that the cutting, flow stopping and the consequential withdrawal of the blade operation is carried out without loss of fluid from the pipe. Part of the apparatus is left on the pipe and encapsulated to complete the operation.
A hot tape saddle fitting (FIG. 1), has means (5) for connecting a pipe to a chamber (4) having an opening of which a rim (14) in use seals with the exterior of a pressurized main pipe encircled by a collar (1). The fitting is characterized in that a cutter (6) within chamber (4) is operable to cut the saddled main pipe in a chordal direction whereby to connect the pipe to the mains pipe. For preference chamber (4) extends as an elongate tubular body (3) in the chordal direction and cutter (6), is hollow, tubular, sharpened at one end (61), closed at the other end (63), and sealing slideable within body (3).
A thermowell or the like is installed in a pipe or similar member without taking the member out of service by first welding an adapter to the surface of the member at the point where the thermowell is to be installed, connecting a gate valve and hot tapping machine to the adapter, drilling a hole in the member through the open gate valve, withdrawing the drill and closing the valve, replacing the drill in the hot tapping machine with the thermowell, opening the gate valve, and installing the thermowell through the open valve. The adapter having a taper internally threaded portion, distal from the ends of a conduit therethrough.
A hot tap connection comprising: (i) a main supply pipe, (ii) a side branch pipe connected to the main supply pipe, (iii) a reinforcing saddle surrounding the main supply pipe and the side branch pipe, (iv) a first gap between the main supply pipe and the reinforcing saddle, (v) a second gap between the side branch pipe and the reinforcing saddle, and (vi) a solid material substantially filling the first gap and the second gap. The method for producing the hot tap connection is also described. The method comprises the steps of: (i) connecting a side branch pipe to a desired location on a main supply pipe; (ii) surrounding the side branch pipe and the main supply pipe with a reinforcing saddle; (iii) defining a first gap between the main supply pipe and the reinforcing saddle, and a second gap between the side branch pipe and the reinforcing saddle; (iv) injecting a pumpable material into the first gap and the second gap; (v) curing the pumpable material to produce a solid material; (vi) cutting a coupon of the main supply pipe within the side branch pipe to produce an opening in the main supply pipe to allow gas to flow therethrough; (vii) removing the coupon from the side branch pipe. The hot tap connection is advantageous as, in most installations, it can be used as a permanent connection between a main supply pipe and a side branch pipe.
