Patent UA-74271-C2 (UA)
Title: Gas non-detachable inlet made of polyethylene and steel branch pipes and method to make the gas non-detachable inlet made of polyethylene and steel branch pipes
Inventor: HOKHFELD VOLODYMYR LEONIDOVYCH
Filed: 2003-12-30
Abstract: Gas non-detachable inlet made of polyethylene and steel branch pipes has an expanded bushing made of copper pipe in soft condition, with bell provided in the bushing at one side, polyethylene branch pipe, this is placed at the outer side of the bushing; at that one of the ends of the polyethylene branch pipe rests at the outer side of the bell of the bushing, and the steel branch pipe with steel end element; at that the steel end element is outside the polyethylene branch pipe, and at the inner surface of the steel end element regular depressions and bosses are provided; at that in the depressions deformed material of polyethylene branch pipe is placed. The steel branch pipe and the steel end element are made of one seamless steel pipe, this has at the whole length wall thickness not less than 6 mm, except of the section made with mechanical processing by cutting the outer surface of the steel end element; at that the thickness of the wall of that section is within 3.0 and 3.5 mm, and the length of the section is equal to five thicknesses of the wall of the section of the steel end element; at that the section named is placed near the end of the bushing at the opposite side of the bell of the bushing; at that inside the section of the steel end element, by mechanical processing by pressure in direction to inside the polyethylene branch pipe a spherical groove is provided, with width within 3.0 and 4.0 mm and depth in the central part equal to half of the width of the groove. At the inner surface of the steel end element the beginning of the mechanical processing by cutting for the first depression is arranged at distance not less than 18 mm from the edge of the section of the steel end element; at that after implementation of the last depression an additional reboring is arranged, to this one before expansion a polyethylene washer with width not less than 3 mm is installed; at that the nominal outer diameter and the nominal width of the wall have dimensions same to that of polyethylene branch pipe, and after expansion the end of the bell of the branch pipe is pressed to the polyethylene washer. The method to make the gas non-detachable inlet made of polyethylene and steel branch pipes is in installation in the steel end element, to reboring, of a polyethylene washer, and after that a bushing made of copper pipe in soft condition, with a bell arranged in the bushing at one side; one installs to the polyethylene branch pipe till support at one end of the polyethylene branch pipe at the outer part of the bell of the bushing; after that the branch pipe with the bushing installed in it is placed to the steel end element till bringing the end of the bell of the bushing to support by polyethylene washer. After that at the opposite end of the bushing one installs to the bushing the front part of the appliance for expansion, this has at the end part diameter decreased by 4.0 in comparison to the diameter of the front part of that appliance; at that the length of the end part of the appliance for expansion is to be not less than the length of the section of the outer surface of the steel end element made by mechanical processing by cutting; after that one begins expansion of the bushing till the end section of the unit for expansion is installed at the zone of the section of the steel end element. After that one stops expansion of the bushing, and after that in the middle of the section of the steel end element, through mechanical processing by pressure in direction to inside the polyethylene branch pipe one arranges a spherical groove with width within 3.0 fn 4.0 mm till the depth obtained in the central part of the groove is equal to half of the width of the groove; after that one continues expansion of the bushing. Design of the inlet and the method to make it make it possible to increase the strength, tightness and reliability.