High Frequency ERW Pipe Mill Production Line

ERW tube or pipes are straight seams electric resistance welded pipe. in brief the ERW pipe, which is a round pipe welded by steel plates. It uses to transport vapor and liquid objects such as oil and natural gas. Electric resistance welding (ERW) refers to a group of welding processes such as spot welding and seam welding. faying surfaces where heat to form the weld is born by the electrical resistance of material combined with the time and the force used to hold the materials together during welding. In general, resistance welding methods are efficient and cause little pollution, however, their applications limited to relatively thin materials.

Electrical resistance welding

Electrical resistance welding will be welders parts formed pressed between two electrodes, and subjected to current, the resistor thermal effects generated by the current flowing through contact with the workpiece surface and the neighboring regions to be heated to melt the plastic state, so that metal-binding method. Resistance welding methods are mainly four types, namely, spot welding, seam welding, projection welding, butt welding.

passed between the two edges of the steel to heat the steel to a point at which the edges are forced together to form a bond without the use of welding filler material.A plate rolled to become a pipe and welded using the Electric Resistance Welding process.

High speed tube mill production line

The manufacturing pipe mill process or High Frequency ERW Pipe Mill Production Line generally involves the following stages in a step by step procedure.

• Slitting
• Uncoiling
• Forming
• Welding
• De beading
• Seam Annealing
• Sizing
• Cutting
• Galvanizing (zink spray)

High frequency straight seam pipe making machine

1. Slitting

Coils slit to predetermine widths for each size of pipes.

 

2. Uncoiling

The slitted coil uncoils at the entry of tube mill line and the ends shear and weld one after another. LOTOS is able to offer the largest range of decoilers from manual to fully automatic, according to a range of strip widths and thicknesses.

 

3. Accumulator

The main action of the accumulator is to accumulate a steel strip to keep continuously and automatically production in the welding pipe line.

 

4. Forming

The slitted coils are formed into a cylindrical shape with open edges utilizing a series of forming rolls.

 

5. Welding

In this stage, the open edges heate to the forging temperature through high-frequency, low-voltage, high current and press welded by forge rolls making perfect and strong.

 

 

6. Sizing

After water quenching, a little decrease applies to pipes with sizing rolls. This results in producing the desirable precise outside diameter.

 

Advantages High Frequency ERW Pipe Mill Production Line

• High production efficiency.
• the machine works stably at a high speed, which improves the yielding of products.
• Low wastage
• High accuracy
• one of the advantages of the ERW tube is that no fusion metals use and the weld seam cannot be seen or felt.

 

Steel tube production line

Ⅰ. PRODUCE CAPACITY

No.	Item	Data	Remark
1	O.D. Of round pipe	Φ32mm～Φ127mm
2	Wall thickness	Round pipe δ1mm～3mm Square pipe δ≤2.5mm
3	MILL SPEED	30M/min～80M/min
4	LENGTH	4M～8M

Ⅱ STEEL STRIPS SPECIFICATION

No.	Item	Data	Remark
1	W.T. of strips	Δ1～3 mm	MATERIAL C.S Q195, 235, Galvanized Steel Strip
2	Width of strips	H100～400mm
3	O.D. of steel coil	Φ800mm～Φ1500mm
4	I..D. of steel coil	Φ450mm～Φ550mm
5	Maxi. Load weight	≤5000kg

 

Ⅲ working flow

Raw material (steel coil) → uncoiling → shearing and butt-welding → material accumulating → non-power leveling →mill-forming → high-frequency welding → removing burrs outside of weld seam → Zinc spraying → cooling → sizing → roughly straightening → fixed length cutting → run-out table

Ⅳ. machine parts details

4.1uncoiler two type: hydraulic expanding

Structure type: Double-side 180ºrotary hydraulic expanding tightly, which insure steel coil feeding alternatively and make steel strip going into accumulator freely.

Structure type	Hydraulic expanding double side
I..D. of steel coil	Φ450mm～Φ550mm
O.D. of steel coil	Φ800mm～Φ1500mm
Width of strips	H60mm～H320mm
Maxi. Load weight	≤5000kg

4.2 Shear and butt-welder

Shearing and butt-welder, which insure double steel tidily and then welding and  leveling weld seam and supply strips for accumulator.

4.3 Vertical accumulator

It have two AC motor: one is feeding motor and the other is driven motor, and ensure steel strips inputting and outputting for forming.

Diameter of accumulator: Φ4500㎜

Feeding motor: YCT250-4A 18.5KW

Driven motor: YCT250-4B  22KW

TUBE MILL COMPONENTS

4.4 FORMING MACHINE

Description	Item	Technical parameters
Horizontal-roll stands	Quantity	Seven stands
	Material of horizontal stands	High-precision forged steel
	Diameter of horizontal shaft	Φ80mm
	Material of horizontal shaft	42CrMO
Vertical-roll stand	Quantity	seven stands
	Material of vertical stands	QT50
	Diameter of horizontal shaft	Φ50mm
	Material of horizontal shaft	45# forged steel
Driven gearbox	Quantity	Seven gearboxes
	Material of gearbox	QT50
	Type	Spiral bevel gear
	Material of gearbox	20CrMnTi
	Material of shaft	40Cr
Power transmission method	From universal transmission joint to horizontal roll stands

Mainly roughly mill-forming steel strip and controlling weld seam.High Frequency ERW Pipe Mill Production Line.

4.5 Guide and squeeze and scraper

One set of guide roll stand for controlling direction of pipe seam to insure pipe seam flatly and straightly entering into extruding rollers.

One set of extruding roll stand for controlling weld seam to realize successful welding.

Two sets of scraper frame for scraping outside weld seam

Description	Technical parameters	Remark
Guide type	Turkish-heads type and 360°rotary
Welding rolls	two welding rollers   or Three welding rollers
Scraper stands	Adjusting pole and quickly feeding and exit

 

4.6 Zinc spraying: Repairing the welding seam Zinc surface

4.7 Cooling type: Sink and shower

tube welding line

4.8 Sizing machine

Description	Item	Technical parameters
Horizontal-roll stands	Quantity	Six stands
	Material of horizontal stands	High-precision cast or forged steel
	Diameter of horizontal shaft	Φ80mm
	Material of horizontal shaft	42CrMO
Vertical-roll stand	Quantity	six stands
	Material of vertical stands	QT50
	Diameter of horizontal shaft	Φ50mm
	Material of horizontal shaft	45# forged steel
Driven gearbox	Quantity	Six gearboxes
	Material of gearbox	QT50
	type	Spiral bevel gear
	Material of gearbox	20CrMnTi
	Material of shaft	40Cr
Power transmission method	From universal transmission joint to horizontal roll stands

Sizing device: Mainly fine shaping pipe after welding and controlling size accuracy. Each 6 sets of horizontal roll stand, vertical roll stand and drive gearbox, 12 sets of universal shaft.(structure same as forming device)

4.9 Roughly straightening machine frame

This unit is used for straightening the pipe after sizing, to reach the required straightness.

	Technical parameters
Straightening stands type	Turk’s head type, and 360°rotary
Diameter of straightening shaft	Φ45mm
Material of straightening shaft	40Cr

4.10 Main driven motor

	Technical parameters
Main driven motor power	2*132 KW
Reducer model	ZLY250

 

4.11 Computer controlled cutting machine

Usage: Cutting online as per setting length

No.	Type	CNC controller, normal/hot cutting
1	Cutting Maxi. Diameter	Φ127mm
2	Cutting Maxi. Wall-thickness	δ3.0mm
3	Cutting tolerance	L=4~8m,  ≤±3mm
4	Cutting driven type	Pneumatic feeding and exit
5	The specification of saw blade	Φ550㎜
6	Cutting motor	37  KW
7	Cutting speed	80M/min