Duplex pipe fitting, exclusive tool for the duplex pipe fitting, refrigeration system employing the duplex pipe fitting, and separation type air conditioner
A duplex pipe fitting includes a fitting main body 1 and a pair of coupling members 2 which are threaded to both ends of the fitting main body 1 . The coupling members 2 are threaded to the fitting main body 1 , so that two pipes P are connected to each other with the fitting main body 1 . Each coupling member 2 includes a holding portion 24 including a holding surface consisting of a pair of or a plurality of pairs of planes facing each other so that it can be held with a general fastening tool. When a rotational torque for tightening the coupling member 2 to the fitting main body 1 reaches a value indicating the completion of fastening, at least a part of the holding portion including the holding surface is separated and the pipe connecting is complete.
1. A duplex pipe fitting comprising a fitting main body having a pair of first thread portions and a pair of coupling members having second thread portions which are threaded to the respective first thread portions of the fitting main body while being attached to pipes to be connected to the fitting main body, each of the coupling member being threaded to the fitting main body so that two pipes are connected to each other with the fitting main body,
wherein each of the coupling members has a holding portion including a holding surface formed of a pair of or a plurality of pairs of planes facing each other, the holding portion being capable of being held with a general fastening tool,
wherein at least a part of the holding portion including the holding surface is separated from the coupling member in the course of pipe connecting,
wherein the coupling member includes a pipe through hole extending along a central axis, a slit formed on the entire circumference of the coupling member in such a manner as to divide the coupling member into two parts, and a thin-wall tubular coupling portion formed between the slit and the pipe through hole,
wherein a portion of the coupling member that is on a side opposite to the fitting main body of the slit is formed as the holding portion, and a portion of the coupling member that is on the same side as the fitting main body of the slit is formed as a pipe connecting portion, the pipe connecting portion including the thread portions that are threaded to the fitting main body and constituting a pipe connecting mechanism for hermetically joining the fitting main body and the pipe,
wherein the part including the holding surface is separated from the coupling member at the tubular coupling portion when the rotational torque for tightening the coupling member to the fitting main body reaches the value indicating the completion of fastening, and
wherein the fitting main body has a cylindrical portion in which the entire pipe connecting portion is accommodated in a state after the fastening is complete, and the coupling member is located at a position where the slit substantially coincides with the end of the cylindrical portion in a state after the fastening is complete.
2. The duplex pipe fitting according to claim 1 , wherein a plurality of engaging holes are formed on an end face opposite to the fitting main body of the pipe connecting portion.
3. The duplex pipe fitting according to claim 2 , wherein the plurality of engaging holes are formed in such a manner as to extend in the axial direction, wherein a plurality of machining holes used for machining the plurality of engaging holes pass through the holding portion, the machining holes being formed at positions corresponding to the engaging holes on the holding portion.
4. The duplex pipe fitting according to claim 3 , wherein the plurality of engaging holes are spaced at equal intervals on a circumference.
5. The duplex pipe fitting according to claim 2 , further comprising a specialized tool that includes a generally semi-annular shaped base body which has an inner diameter larger than the outer diameter of the pipe, a handle attached to the base body and engaging projections formed on the side face of the base body, which are engaged with the engaging holes.
6. A refrigeration system, wherein the duplex pipe fitting according to claim 1 is used in a refrigerant circuit.
7. A separation type air conditioner, wherein an indoor unit installed in a room and an outdoor unit installed outside a room are connected to each other with a communication pipe installed on site, wherein the communication pipe is connected with the duplex pipe fitting according to claim 1 .
8. A separation type air conditioner, wherein an indoor unit installed above a ceiling and an outdoor unit installed outside a room are connected to each other with a communication pipe installed on site, wherein the communication pipe is connected above the ceiling with the duplex pipe fitting according to claim 1 .