Mould pipe protecting centrifugally cast thin-wall gray cast iron socket pipe against fracture

The invention relates to the field of centrifugal casting, in particular to a mould pipe protecting a centrifugally cast thin-wall gray cast iron socket pipe against fracture. The problem that when a thin-wall straight pipe with a socket at one end is manufactured through centrifugal casting, a socket and straight pipe connection section fractures frequently and consequently product quality is affected is solved. The mould pipe comprises a metal mould pipe body, a socket section moulding sand core, a metal gland and gland fastening pins, wherein the socket section moulding sand core and the metal mould pipe body are fixed through the metal gland and the gland fastening pins. An outer sand core is additionally arranged in the metal mould pipe body, the outer sand core is fixed in the metal mould pipe body through the metal gland and the gland fastening pins and adjoins the socket section moulding sand core, and the outer sand core and the socket section moulding sand core are matched to form a socket section moulding space of the centrifugally cast thin-wall gray cast iron socket pipe. The mould pipe is simple and reasonable in structure, convenient to operate and capable of greatly increasing the product qualification ratio of thin-wall gray cast iron socket pipes manufactured through the centrifugal casting process.