A method and apparatus for bending a pipe to mitigate internal wrinkling, with particular benefit when bending a lined pipe upon spooling. Bending is performed continuously by advancing the pipe through a bending zone while an internal mandrel is held at the bending zone to resist wrinkling. In one variant, the mandrel comprises longitudinally-spaced pipeengaging elements and a tensile link between the elements allows relative movement between the elements. A holdback connection on one of the elements applies hold-back force to that element to be transmitted to the other element via the tensile link. In another variant, the mandrel comprises an elongate pipe-engaging body with a hold-back connection at one end of the body. The body is flexible to bend with the pipe and is shaped to engage an inner surface of the pipe along most of the length of the body.

The purpose of the present invention is to provide a method for producing a pipe material and to provide a mandrel with which resistance between a member to be processed and the mandrel during bending processing can be reduced and overall processing time can be shortened. The method for producing a pipe material includes: a step for inserting a mandrel, which is provided on the inside thereof with a flow path through which dry ice powder flows and spray holes at the tip thereof for spraying the dry ice powder, inside pipe material; a step for spraying the dry ice powder from the spray holes inside the pipe material; and a step for performing bending processing on the pipe material wherein the mandrel has been inserted.

A method and an apparatus bend a pipe to mitigate internal wrinkling, with particular benefit when bending a lined pipe upon spooling. Bending is performed continuously by advancing the pipe through a bending zone while an internal mandrel is held at the bending zone to resist wrinkling. In one variant, the mandrel includes longitudinally-spaced pipe-engaging elements and a tensile link between the elements allows relative movement between the elements. A hold-back connection on one of the elements applies hold-back force to that element to be transmitted to the other element via the tensile link. In another variant, the mandrel includes an elongate pipe-engaging body with a hold-back connection at one end of the body. The body is flexible to bend with the pipe and is shaped to engage an inner surface of the pipe along most of the length of the body.

A push-bending forming device for titanium alloy tubes is provided, which includes a die main body, a plurality of filling balls, a differential temperature assembly and a punch. The filling balls are configured to be filled in a tube blank, and are made of a metal material, with a heat-resistance temperature over 500 C. A diameter of the filling ball is less than an inner diameter of the tube blank. The punch includes a first pushing part and a second pushing part. A push-bending forming method using such device is also provided.

A push-bending forming device for titanium alloy tubes is provided, which includes a die main body, a plurality of filling balls, a differential temperature assembly and a punch. The filling balls are configured to be filled in a tube blank, and are made of a metal material, with a heat-resistance temperature over 500 C. A diameter of the filling ball is less than an inner diameter of the tube blank. The punch includes a first pushing part and a second pushing part. A push-bending forming method using such device is also provided.

A push-bending forming device for titanium alloy tubes is provided, which includes a die main body, a plurality of filling balls, a differential temperature assembly and a punch. The filling balls are configured to be filled in a tube blank, and are made of a metal material, with a heat-resistance temperature over 500 C. A diameter of the filling ball is less than an inner diameter of the tube blank. The punch includes a first pushing part and a second pushing part. A push-bending forming method using such device is also provided.

A push-bending forming device for titanium alloy tubes is provided, which includes a die main body, a plurality of filling balls, a differential temperature assembly and a punch. The filling balls are configured to be filled in a tube blank, and are made of a metal material, with a heat-resistance temperature over 500 C. A diameter of the filling ball is less than an inner diameter of the tube blank. The punch includes a first pushing part and a second pushing part. A push-bending forming method using such device is also provided.

A system for imposing a permanent bend in a length of tubing, includes a bend setting portion having surface, a groove extending inwardly of the surface, the groove having a dimension which is smaller than an outer dimension of a tubing to be bent therein a fixing element extendable to secure a tubing in the groove, and a heater configured to heat the bend setting portion to a fixing temperature.

A system for imposing a permanent bend in a length of tubing, includes a bend setting portion having surface, a groove extending inwardly of the surface, the groove having a dimension which is smaller than an outer dimension of a tubing to be bent therein a fixing element extendable to secure a tubing in the groove, and a heater configured to heat the bend setting portion to a fixing temperature.