Pipe fitting having anti-loosening structure

A pipe-fitting comprising:

• a main body including:
• a plurality of pipe receiving portions for receiving a plurality of pipes therein respectively;
• and a hollow joint for connecting the plurality of pipe receiving portions to each other;
• a sealing member received in a sealing member-receiving groove defined in a distal end of each pipe receiving portion of the plurality of pipe receiving portions, wherein the sealing member is configured to seal between each pipe receiving portion and each pipe inserted into each pipe receiving portion;
• and
• a plurality of fixing-caps having a through-hole defined therein through which each pipe of the plurality of pipes passes, respectively, wherein each fixing-cap of the plurality of fixing-caps is screwed to the distal end of each pipe receiving portion to press the sealing member to be brought into close contact with each pipe,
• wherein a fixing-cap stopper is formed on an outer circumferential face of the distal end of each pipe receiving portion, wherein the fixing-cap stopper contacts a proximal end of the fixing-cap when each fixing-cap is screwed to the distal end of each pipe receiving portion,
• wherein the fixing-cap stopper includes a fixing-cap fixing portion including a plurality of fixing protrusions protruding toward the proximal end of the fixing-cap and in the opposite direction to the insertion direction of each pipe,
• wherein a plurality of fixing-protrusion-receiving grooves is defined in the proximal end of each fixing-cap for receiving the fixing-protrusions therein respectively,
• wherein each fixing-cap includes:
• an annular portion defining the through-hole;
• a skirt portion extending from an edge of the annular portion in an insertion direction of each pipe;
• and
• a pressing portion formed between an inner circumferential surface of the annular portion and an inner circumferential surface of the skirt portion,
• wherein a pressing protrusion extends from a proximal end of the pressing portion in the insertion direction of each pipe, and the pressing portion has an inner inclined surface having a predetermined inclination angle extending to the pressing protrusion with respect to the inner circumferential surface of the annular portion, and
• wherein the inclination angle is in a range of 14 and 22 degrees.