Manufacturing process of double-mouthing nodular cast iron pipe

Abstract

The invention discloses a manufacturing process of a double-mouthing nodular cast iron pipe. The process includes the steps that (1) filling a dotted pouring die into a centrifugal pipe casting machine, and introducing cooling water into the outer wall of the pouring die for cooling; a manufactured sand mold core is installed on a cast steel core frame, and the cast steel core frame is installed at the mouthing end of a pouring mold; (2) spheroidizing and slagging off molten iron, and pouring the molten iron into a sector pouring ladle of the centrifugal pipe casting machine for pouring; (3) starting a pipe drawing system of the centrifugal tube casting machine, and pouring molten iron into the inner wall of the pouring mold to start pipe drawing; (4) pulling out the double-mouthing nodular cast iron pipe after drawing and molding, and annealing and removing the sand mold core; (5) a socket weld ring is welded to a socket; and (6) a sealing ring is arranged inside a sealing chamber ofa mouthing, and an anti-pulling-off ring is arranged inside an anti-pulling-off chamber. The adopted sand mold core is simple in manufacturing process, materials are not prone to deformation, the pipedrawing operation speed of the pipe drawing system of the centrifugal pipe casting machine is reasonably set, and the pipe casting quality is effectively guaranteed.

Description

technical field [0001] The invention belongs to the field of ductile iron pipe manufacture, and in particular relates to a manufacturing process of a double-socket ductile iron pipe. Background technique [0002] The most common type of joint for ductile iron pipes is a socket slide-in T-type joint. When installing, insert one end of the socket of the cast iron pipe directly into the socket of another pipe, and seal the connection with a sealing rubber ring in the middle. The socket interface form has the characteristics of simple structure, convenient installation and good sealing performance. The interface can adapt to a certain foundation deformation and has a certain anti-seismic ability. At the same time, the deflection angle can be used to realize the long-distance steering of the pipeline. [0003] In the prior art, in the manufacturing process of ductile iron pipes, the sand core installed on the cast steel core frame is the inner core mold of the socket, and the en...

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Problems solved by technology

[0003] In the prior art, in the manufacturing process of ductile iron pipes, the sand core installed on the cast steel core frame is the inner core mold of the socket, and the end part plays a role in preventing the leakage of molten iron. In the prior art The sand core used is easily deformed when it is washed by molten iron, so the choice of sand core material is particularly important, otherwise it will directly affect the casting quality of the socket

In addition, the setting of the sealing cavity of the sand mold core and the corresponding model module of the anti-stripping cavity will directly affect the casting shape of the sealing cavity and the anti-stripping cavity. The working surface of the core mold in the prior art is single, and the sealing cavity and The anti-stripping cavity is easy to be deformed due to the accumulation and loss of molten iron and affect the use

In the prior art, when the centrifugal pipe casting machine draws the pipe, its speed remains basically unchanged. If the set pipe drawing speed is too fast, the shape of the cast pipe still in a high temperature state will be affected due to stretching, and its quality will be damaged. , if the speed is too slow, it will affect the production efficiency of cast pipe

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