A polyethylene for a pipe and a joint of the present invention satisfies the following characteristics (1) to (5): Characteristic (1): a melt flow rate at a temperature of 190 C. and a load of 21.6 kg (HLMFR) is 5 to 20 g/10 minutes, Characteristic (2): a density (D) is 0.954 to 0.960 g/cm.sup.3, Characteristic (3): a ratio of weight-average molecular weight (Mw) and number-average molecular weight (Mn) (Mw/Mn) measured by gel permeation chromatography (GPC) is 15 to 27, Characteristic (4): a rupture time at 80 C. and 5 MPa by a full notch creep test (FNCT) is 150 hours or more, and Characteristic (5): a Charpy impact strength (CIS) measured at 20 C. is 8.5 kJ/m.sup.2 or more.

A high pressure pipe coupling construction includes at least one high pressure pipe (2) as well as a coupling (22) connected to the pipe (2). The pipe consists a reinforcement layer (4) of helically arranged fibers (6, 7) and the coupling (22) consists an inner sleeve (23) sealed with respect to the inner surface of the pipe and at least one metal outer sleeve (9). The metal outer sleeve (9) has an overlapping outer sleeve part (29) overlapping the inner sleeve (23) in axial direction and a protruding outer sleeve part (25) protruding in axial direction with respect to the inner sleeve (23), which overlapping outer sleeve part (29) and protruding outer sleeve part (25) are connected to the outer surface of the pipe (2). The inner sleeve (23) consists of a plastic material; at the location of overlap between the inner sleeve (23) and the pipe (2), the maximum outer diameter of the inner sleeve (23) is smaller than or equal to the minimum inner diameter of the pipe (2).

A high pressure pipe coupling construction includes at least one high pressure pipe (2) as well as a coupling (22) connected to the pipe (2). The pipe consists a reinforcement layer (4) of helically arranged fibers (6, 7) and the coupling (22) consists an inner sleeve (23) sealed with respect to the inner surface of the pipe and at least one metal outer sleeve (9). The metal outer sleeve (9) has an overlapping outer sleeve part (29) overlapping the inner sleeve (23) in axial direction and a protruding outer sleeve part (25) protruding in axial direction with respect to the inner sleeve (23), which overlapping outer sleeve part (29) and protruding outer sleeve part (25) are connected to the outer surface of the pipe (2). The inner sleeve (23) consists of a plastic material; at the location of overlap between the inner sleeve (23) and the pipe (2), the maximum outer diameter of the inner sleeve (23) is smaller than or equal to the minimum inner diameter of the pipe (2).

Disclosed are a method, an extruder and an injection molding machine for manufacturing a clamping ring, solving problems that products produced by an extrusion method needs to be processed in two steps. The key point of technical solutions lie in a molding step of acting on a pipe member in a plastic melt state via a molding die set, to form a clamping ring from the pipe member; an injection mold injects plastic materials having memory properties through an injection gate to form a pipe member in the molding cavity, the pipe member comprises a clamping ring and a sealing film provided on one end of the clamping ring, the hydraulic mechanism drives a molding cutter to cut out a joint of the sealing film and the clamping ring in a plastic melt state, thereby a limit end is formed at one end of the clamping ring.

Disclosed are a method, an extruder and an injection molding machine for manufacturing a clamping ring, solving problems that products produced by an extrusion method needs to be processed in two steps. The key point of technical solutions lie in a molding step of acting on a pipe member in a plastic melt state via a molding die set, to form a clamping ring from the pipe member; an injection mold injects plastic materials having memory properties through an injection gate to form a pipe member in the molding cavity, the pipe member comprises a clamping ring and a sealing film provided on one end of the clamping ring, the hydraulic mechanism drives a molding cutter to cut out a joint of the sealing film and the clamping ring in a plastic melt state, thereby a limit end is formed at one end of the clamping ring.

A system and method for coupling sections of pipe is disclosed, wherein the system preferably comprises a frame, a carriage and a controller. In embodiments, the frame comprises a pipe frame, which preferably extends substantially the entire length of the system and may be secured via a chain. The system in a preferred embodiment may be secured to a piece of machinery, such as an excavator bucket, back hoe or equivalent machinery for moving a first section of pipe to a location where a second section of pipe resides for coupling the first and second sections of pipe. Methods of use are also disclosed herein.

A system and method for coupling sections of pipe is disclosed, wherein the system preferably comprises a frame, a carriage and a controller. In embodiments, the frame comprises a pipe frame, which preferably extends substantially the entire length of the system and may be secured via a chain. The system in a preferred embodiment may be secured to a piece of machinery, such as an excavator bucket, back hoe or equivalent machinery for moving a first section of pipe to a location where a second section of pipe resides for coupling the first and second sections of pipe. Methods of use are also disclosed herein.

A tubing including an overmold is connected to a fitting by welding the overmold to the fitting. Methods for doing the same are also provided. Also provided are methods for forming an overmold on a tubing or on a tubing and fitting assembly.

An electrofusion coupling member made of a thermoplastic substance having aluminum particles incorporated therein and further comprising an electric resistance heating element disposed therein, an electrofusion coupler device which includes the same, and a method for welding the device to other thermoplastic objects are provided herein.

A hydraulic joint is disclosed. The hydraulic joint includes a tube, a hydraulic fitting, and a tip seal. The hydraulic fitting may be positioned around the tube. The hydraulic fitting may include a first open end for receiving the tube. The tip seal may be configured to define an opening that allows for the passage of leaks. The tip seal may be positioned on the hydraulic fitting adjacent the open end and forming a mechanical barrier between the fitting and the tube.