The investigations carried out in VNIIMETMASH permit to generate the method for production of straight-line tubes with wery thin walls. The method essence is: the tube is straightened in the closed pass which is formed through 3 elongated rolls. Two side rolls are set up to the angle less than nominal and the upper roll-to the angle more than nominal.

The straightener consists of the stand in which three sliders are set at an angle 120°. They carry the work rolls. Every slider has devices for radial and angle adjustment. The rolls have a separate drive. The slider is balanced with a hydraulic cylinder. This protects the machine from overloads and secures the straightening of tubes with upsetting ends. Depending on the tube range the machine has changeable roll set. For the roll change simplification the C-hook roll changer is dumped through the hydraulic drive.

The design of these machines is protected with patent DE 3050310 C2.

The tubes of traightened with high precision are used in production of electric pump housing for pumping out oil from deep wells. The high degree of linearity allows to increase the pump resource. diameter 90…130 mm are s

The 32…89 mm diameter tubes with upsetting ends used in geological exploration. Enhanced linearity permits to increase the rate and depth of drilling.

Machines for precision straightening of tubes operate in Russia and Ukraine.

Cooperation proposals:

• Development and production of machines for precision straightening of tubes of wide rolled stock at a customer's requirementy;

• Development and supply of the optimal process of tube finishing to achieve the highest precision of straightening.