Pipe elements have circumferential grooves. The grooves have a first side surface contiguous with a first floor surface. The first side surface and the first floor surface together subtend a first 90° circular arc when viewed in cross section. The grooves also have a second side surface contiguous with a second floor surface. The second side surface is in spaced relation to and in facing relation with the first side surface. The second side surface and the second floor surface together subtend a second 90° circular arc when viewed in cross section. A third floor surface is contiguous with both the first and second floor surfaces and is a flat surface. A coupling used to connect the pipe elements has arcuate projections which engage the grooves of the pipe elements. The arcuate projections have a semi-circular cross section. Relief grooves are positioned adjacent to each arcuate projection.

Pipe elements have circumferential grooves. The grooves have a first side surface contiguous with a first floor surface. The first side surface and the first floor surface together subtend a first 90° circular arc when viewed in cross section. The grooves also have a second side surface contiguous with a second floor surface. The second side surface is in spaced relation to and in facing relation with the first side surface. The second side surface and the second floor surface together subtend a second 90° circular arc when viewed in cross section. A third floor surface is contiguous with both the first and second floor surfaces and is a flat surface. A coupling used to connect the pipe elements has arcuate projections which engage the grooves of the pipe elements. The arcuate projections have a semi-circular cross section. Relief grooves are positioned adjacent to each arcuate projection.

Pipe elements have circumferential grooves. The grooves have a first side surface contiguous with a first floor surface. The first side surface and the first floor surface together subtend a first 90° circular arc when viewed in cross section. The grooves also have a second side surface contiguous with a second floor surface. The second side surface is in spaced relation to and in facing relation with the first side surface. The second side surface and the second floor surface together subtend a second 90° circular arc when viewed in cross section. A third floor surface is contiguous with both the first and second floor surfaces and is a flat surface. A coupling used to connect the pipe elements has arcuate projections which engage the grooves of the pipe elements. The arcuate projections have a semi-circular cross section. Relief grooves are positioned adjacent to each arcuate projection.

In order to widen the field of application of a stretcher-leveler having a minimum nominal width, at least one gripping head of the stretcher-leveler is connected to an adapter having clamping elements for clamping a plate to be stretched, the adapter having a nominal width that is smaller than the minimum nominal width of the stretcher-leveler, and a plate being stretched is connected to the gripping head via the adapter clamping elements and the adapter, before starting the stretching process.

In order to widen the field of application of a stretcher-leveler having a minimum nominal width, at least one gripping head of the stretcher-leveler is connected to an adapter having clamping elements for clamping a plate to be stretched, the adapter having a nominal width that is smaller than the minimum nominal width of the stretcher-leveler, and a plate being stretched is connected to the gripping head via the adapter clamping elements and the adapter, before starting the stretching process.

The ratio of the difference between a surface distance L at each of the different positions in a width direction DW of a metal sheet and a minimum surface distance Lm to the minimum surface distance Lm is an elongation difference ratio. The elongation difference ratio in a center section in the width direction DW of the metal sheet is less than or equal to 3×10.sup.−5. The elongation difference ratios in two edge sections in the width direction DW of the metal sheet are less than or equal to 15×10.sup.−5. The elongation difference ratio in at least one of the two edge sections in the width direction DW of the metal sheet is less than the elongation difference ratio in the center section in the width direction of the metal sheet.

A plate and strip rolling process oriented efficient and stable current applying manipulator is provided, which aims to effectively avoid potential safety hazards caused integral electrifying of the rack during normal current applying, can improve the defects that current loss is caused by a normal current applying way and the service life of the roller is shortened, and the difficulty in applying pulse current to plate strips while rolling plate strips with limited length dimensions at a higher temperature, and can realize stable loading of pulse current with limited dimension, and effectively act pulse current within a rolling region.

An integrated flattening, cutting, and collecting assembly includes a frame, a conveyor seat, and a processing rack. The processing rack is provided with a flattening cylinder and cutting cylinders, a flattening block cooperating with a steel sheet being conveyed by the conveyor seat, a cutting lift seat disposed beneath the cutting cylinders, the cutting lift seat being provided with a cutter and cutting pressing blocks, and wherein the distance between the two cutting pressing blocks is smaller than the length of the flattening block. In addition, the lower end of the cutter is disposed beneath the lower ends of the cutting pressing blocks, and this distance is the same as the thickness of the steel sheet being conveyed. The cutting pressing blocks can press and hold the steel sheet during cutting, while not affecting the cutting of the cutter, whereby the accuracy of the steel sheet cutting is greatly improved.

The present disclosure discloses a system for intelligently leveling with an automatic temperature control function and a method thereof. The system includes a handcart-type leveller, indoor GPS positioning devices, an AGV trolley temperature measuring device and a control system. The control system processes position parameters of the AGV trolley temperature measuring device and the handcart-type leveller; converts the position parameters for the handcart-type leveller into position parameters for a leveling region, controlling the AGV trolley temperature measuring device to arrive at a lower part of the leveling region by a control chip and measuring temperatures in the leveling region; controlling an operation status of the AGV trolley temperature measuring device and transmitting data with the AGV trolley temperature measuring device. The method of the present disclosure is capable of intelligently controlling leveling temperatures and leveling time in the leveling region according to preset data parameters, thereby having excellent leveling effects.

A system for flattening steel plates includes crane, a first conveyor, a second conveyor, a first shape detector, a second shape detector, a first rangefinder, a second rangefinder, a first detection device, a second detection device, a first idler roller, a second idler roller, a flattening machine, a first robot, a second robot, a third robot, and a fourth robot. The flattening machine is connected to one end of the first conveyor and one end of the second conveyor. The first shape detector is disposed above a middle part of the first conveyor. The second shape detector is disposed above a middle part of the second conveyor. The first rangefinder is disposed at one end of the first conveyor. The first detection device is disposed between the first rangefinder and the flattening machine. The second rangefinder is disposed on one end of the flattening machine.