Piping system comprising pipe block

A piping system comprising:

• a first pipe;
• a second pipe;
• and
• a pipe block coupled to the first pipe and the second pipe,
• wherein the first pipe comprises:
• a flange positioned at an end portion of the first pipe, protruding in a radially outward direction of the first pipe along an outer circumference of the first pipe, and
• a coupling portion having a nipple that is inserted into the pipe block,
• an o-ring seating groove formed along a circumferential surface of the nipple in a lateral direction,
• wherein the flange comprises a first surface and a second surface positioned in an opposite direction of the first surface, and
• wherein the second pipe comprises:
• a bending portion with a curvature;
• and
• wherein the pipe block comprises:
• a pipe insertion portion coupled to the second pipe;
• an insertion hole into which the first pipe is insertively coupled;
• a lip protruding from a surface in which the insertion hole is formed in a circumferential direction along an outer circumference of the insertion hole,
• a flange coupling surface positioned between the insertion hole and the lip along the outer circumference of the insertion hole and facing the first surface of the flange, and
• wherein an inner diameter of the lip is equal to or greater than an outer diameter of the flange,
• wherein, when the first pipe is coupled to the pipe block, the flange is positioned within the inner diameter of the lip, and the lip is plastically deformed toward the second surface of the flange to caulk the flange, so that the first pipe is fixed to the pipe block,
• wherein a seal, positioned between the first surface of the flange and the flange coupling surface seals between the first surface of the flange and the flange coupling surface and made of a first elastic material and the first pipe is fixed to the pipe block;
• wherein an o-ring, seated in the o-ring seating groove, is in tight contact with an inner wall of the insertion hole so that that the o-ring seals between the insertion hole and a surface of the nipple,
• wherein the pipe insertion portion has a curvature corresponding to the curvature of the bending portion to fix the second pipe to the pipe insertion portion,
• wherein the seal comprises a first ring comprising the first elastic material and a second ring comprising a material having a hardness greater than a hardness of the first ring, and
• wherein the o-ring comprises a second elastic material.