A plate-type refrigerant pipe includes: a first plate made of stainless steel; a second plate made of stainless steel; and a coupling pipe, made of a material that is different from stainless steel, attached to one or both of the first plate and the second plate. The first plate and the second plate are joined to form a refrigerant flow path. The coupling pipe is connected to a refrigerant pipe at a connecting surface of refrigerant pipe. The material of the coupling pipe is identical to a material of the connecting surface of the refrigerant pipe.

A plate-type refrigerant pipe includes: a first plate made of stainless steel; a second plate made of stainless steel; and a coupling pipe, made of a material that is different from stainless steel, attached to one or both of the first plate and the second plate. The first plate and the second plate are joined to form a refrigerant flow path. The coupling pipe is connected to a refrigerant pipe at a connecting surface of refrigerant pipe. The material of the coupling pipe is identical to a material of the connecting surface of the refrigerant pipe.

Provided is a connection structure of a metal corrugated pipe, including: a first connection member including a first connection member inner guide straight pipe and a first connection member inner inclined pipe; the metal corrugated pipe inserted into the first connection member inner guide straight pipe and the first connection member inner inclined pipe of the first connection member; a second connection member fitted on an outer side of the metal corrugated pipe, and screw-coupled to the first connection member; a metal packing fitted on the outer side of the metal corrugated pipe, and inserted into the first connection member inner guide straight pipe and the first connection member inner inclined pipe so as to be pipe-reduced to form a curved surface; and a separation prevention ring configured to fix the metal packing to prevent the metal packing from being separated.

Provided is a corrugated pipe connection device. The device includes a corrugated pipe including a groove and a ridge that are successively and alternately formed, a nut into which one side portion of the corrugated pipe is inserted, wherein the nut has a screw-thread on an inner circumferential surface thereof, a clamping ring being formed in a ring shape cut at one place thereof and including an inner portion formed convexly in a radially inward direction of the corrugated pipe to be inserted into the groove of the corrugated pipe and an outer portion protruded in a radially outward direction from the inner portion, wherein the outer portion comprises an outer circumferential surface, and a socket having a screw-thread on an outer circumferential surface thereon onto which the nut is screwed.

Provided is a corrugated pipe connection device. The device includes a corrugated pipe including a groove and a ridge that are successively and alternately formed, a nut into which one side portion of the corrugated pipe is inserted, wherein the nut has a screw-thread on an inner circumferential surface thereof, a clamping ring being formed in a ring shape cut at one place thereof and including an inner portion formed convexly in a radially inward direction of the corrugated pipe to be inserted into the groove of the corrugated pipe and an outer portion protruded in a radially outward direction from the inner portion, wherein the outer portion comprises an outer circumferential surface, and a socket having a screw-thread on an outer circumferential surface thereon onto which the nut is screwed.

A corrugated pipe connection device is completely coupled by primarily screwing a nut and a socket after interposing a clamping ring between the nut and the socket, inserting an one-side portion of a corrugated pipe, including a groove and a ridge that are successively and alternately formed, into the nut, and secondarily screwing the nut and the socket so that an inner portion of the clamping ring is inserted into the groove of the corrugated pipe and a distal end of the corrugated pipe is pressed. The corrugated pipe connection device is easily coupled in a simplified manner and is capable of achieving enhanced sealing efficiency.

A corrugated pipe connection device is completely coupled by primarily screwing a nut and a socket after interposing a clamping ring between the nut and the socket, inserting an one-side portion of a corrugated pipe, including a groove and a ridge that are successively and alternately formed, into the nut, and secondarily screwing the nut and the socket so that an inner portion of the clamping ring is inserted into the groove of the corrugated pipe and a distal end of the corrugated pipe is pressed. The corrugated pipe connection device is easily coupled in a simplified manner and is capable of achieving enhanced sealing efficiency.

A system for connecting and sealing flexible and rigid pipes under high pressure comprises a flexible pipe, rigid pipes, and transition connectors, wherein two ends of each transition connector are respectively connected with the flexible pipe and one rigid pipe, external sides of the flexible pipe and the transition connectors are coated with a rubber layer, buckling sleeves are buckled on the rubber layer outside the transition connectors, aluminum alloy connectors are embedded into external surfaces, extending out of the rubber layer, of the transition connectors, and external buckling sleeves are buckled on external surfaces of the aluminum alloy connectors.

A system for connecting and sealing flexible and rigid pipes under high pressure comprises a flexible pipe, rigid pipes, and transition connectors, wherein two ends of each transition connector are respectively connected with the flexible pipe and one rigid pipe, external sides of the flexible pipe and the transition connectors are coated with a rubber layer, buckling sleeves are buckled on the rubber layer outside the transition connectors, aluminum alloy connectors are embedded into external surfaces, extending out of the rubber layer, of the transition connectors, and external buckling sleeves are buckled on external surfaces of the aluminum alloy connectors.

A hose assembly includes a metal hose, an end connection having a distal end defining a fluid connector and a proximal end defining a tube stub received in a distal end portion of the hose, and a weld collar surrounding the distal end portion of the hose and the tube stub of the end connection, with the weld collar, the hose distal end portion, and the tube stub being welded together at a welding zone proximal to a distal edge of the metal hose.