Plastic valve for preventing distortion

1. A pipe connection device comprising:

a connection member made up of plastic;

a case member formed on an outer surface of the connection member; and

a flange member made up of plastic and formed at an end part of the connection member,

wherein a pipe is connected by being inserted into a hole of a central part of the connection member, a distortion prevention member for minimizing a force corresponding to distortion applied in a direction opposed to a direction of the connection is formed in the flange member,

wherein the connection member is made up of fluoride resin and the case member is made up of engineering plastic,

wherein the distortion prevention member is formed in the flange member through an insert molding, at least one first hole is formed on the distortion prevention member into which melted plastic is filled by the insert molding to combine the distortion prevention member with the flange member, and at least one second hole is formed on the distortion prevention member into which a bolt is inserted to connect the flange member to another flange member, and

wherein the at least one first hole is not formed in the connection member.

2. The pipe connection device of claim 1 , wherein the distortion prevention member includes a metal member, and the metal member includes a body and at least one protrusion projected from the body for minimizing the force corresponding to the distortion.

3. The pipe connection device of claim 2 , wherein the protrusion is extended from the body in a direction of an end of the flange member.

4. The pipe connection device of claim 1 , wherein the distortion prevention member further includes a first protrusion and a second protrusion projected from the body in an opposite direction,

wherein the first protrusion exists in the flange member, and a part of the second protrusion exists outside of the flange member,

wherein a length of the second protrusion is higher than a length of the first protrusion.