Welded tube mill

                         Welded tube mill- making welded pipes from 10 to 127mm diameter

II. The technical flow of the production line

{SteelTape}→→ Single-arbor un-coiler →→Strip-head Cutter and welder→→

Spiral Accumulator→→Forming section(Flattening unit +Main driving unit +Forming unit +Guide unit +High frequency induction welding unit +squeeze roller)+ De-burr frame →→Cooling unit →→ Sizing unit and straightener →→Flying saw under computer-control →→ Run-out table→→straightening

III. Basic conditions:

a) Steel Pipe Specification

1. Round Pipe diameter:       Φ10 –Φ127mm

Pipe Thickness:             1.5 – 5.0mm

2. Square Pipe:              30X30mm –100X100mm

Rectangle Pipe:             20X40mm –120X80mm

Pipe Thickness:             1.5 – 5.0mm

3. Pipe Length:               6.0m – 12.0m

4. Length Tolerance:           0-6mm

b) Steel Tape Specification

1. Material:                  Low Carbon steel (δb≤500Mpa, δs≤235Mpa)

2. Steel Tape: Inner diameter:   Φ510-610mm

Outer diameter:   Max.Φ1800mm

Strip steel width:   120mm-400mm

Strip steel thickness: 1.5mm-5.0mm

The maximum weight: 6.0 tons

c) Electricity

1. Dynamic power: AC380V±10%, 3phases, 50Hz±1.0%

2. Control Power: AC220V±10%, one phase, 50 Hz ±1.0%

d) Electric installed capacity:     appro. 900KW

e) Cooling water

1. Reservoir for High Frequency equipment: 30 m³, one set

2. Reservoir for circulating cooling water:     25 m³, one set

f) Compressed air

1. Pressure:   0.4Mpa

2. Flow:       3.0m³/h

g) Production capacity

Annual output: 70000 ton, according to the yearly working days, daily working hours and the products.

h) Line speed: 30-60m/min

IV. Equipment makeup and main parameters of single unit:

1. Hydraulic Single-arbor uncoiler with peeler

1.1. Parameters:

-     Coil width:   max.400mm

-     Coil OD:      max. Φ1800mm

-     Coil ID:          max.Φ508mm

-     Coil weight:   max. 6.0 tons

1.3. Mandrel expansion by hydraulic

2. Five-roll Flattener

2.1 Brief:

There are pairs of nipping and sending roller. Flatten rolls are arranged for two top and three below. Nipping and sending is pressured by hydraulic cylinder, flatter roll motor is cogged by worm wheel and worm screw reduced speed, the worm screws in front and one in back can come true be in-phase by sleeve connecting, which can ensure top leveling roll and under leveling roll be parallel, thereby which reach in the intention of flatten.

2.2 Parameters:

-     Quantity of withdrawal roll:     2

-     Material of withdrawal roll:     40Cr

-     Quantity of flattener roll:       5

-     Flattener Speed:             10m/min

-     Rigidity of Roller:             HRC50-60

3. Shearing & butt welding machine of welded tube mill

3.1 Hydraulic shearing parameters machine:

-     Cutting by hydraulic system

-     Width:       ≤400mm

-     Thickness:   ≤ 5.0mm

3.2 Butt welding machine by manual

-     welding machine

4. 3. Horizontal spiral accumulator (O.D.: 5.0m) of welded tube mill

3.1   Low bracket:         1 set

3.2   Revolver:             1 set

3.3   7 rollers flattening unit: 1 set

3.4   2 rollers feeding:       1 set

3.5   Accumulator:         1 set

-   Feeding speed:         Max.200m/min

-   Storing capacity:       500meter -700 meter

3.6   High bracket:         1 set

3.7   Hydraulic system       1 set

3.8   Electrical system       1 set

3.9   Motor: Feeding motor: 30KW

           Accumulator:   37KW

5. Forming & sizing section of welded tube mill

5.1   Forming mill gearbox, universal joint

5.1.1   Mill entry flattener by up-horizontal roll and below-horizontal roll, one positive five-roll flattener, one pair of feeding vertical roll.

5.1.2   Forming mill consists of:

-     Driven stand:            7 sets (Horizontal)

-            Driven stand shaft:             Φ 110mm

-     Material of shaft:         40Cr

-            Side roll stand:              8 sets(Vertical)

-            Side roll stand shaft:        Φ70mm

-     Material of shaft:         40Cr

-            Gear box & universal joint: 7sets

-     Material of gear box:     cast steel

-     Material of bevel gear:   20CrMnTi

-     Main motor:            110kW   1 set

-     Main redactor:           ZLY280   1 set

-     Horizontal roller frame with worm gear & shaft. adjust up and down at same time and level.

5.2             Sizing mill gear box, universal joint

5.2.1   Sizing mill consist of:

-                   Driven stand:          5 sets (Horizontal)

-            Driven stand shaft:               Φ 110mm

-     Material of shaft:         40Cr

-            Side roll stand:                5 sets (Vertical)

-            Side roll stand shaft:        Φ 70mm

-     Material of shaft:         40Cr

-            Gear box & universal joint: 5 sets

-     Material of gear box:     cast steel

-     Material of gear:           20CrMnTi

-     Main motor:            160kW   1 set

-     Main redactor:           ZLY280   1 set

-     2 sets single head Turkshead, with 4 rollers*2sets

-     One speed testing roller with air cylinder for CNC flying saw

-     Horizontal roller frame with worm gear & shaft. adjust up and down at same time and level.

6. Welding section of welded tube mill

6.1          Welding section consist of:

         -        Seam guide unit:                         1 set

         -        Squeeze stand:                   4 rollers(Φ80mm)  

         -        De-burr frame:                     1 set (2 heads)

-         Horizontalunit for seam ironing:     2 rollers

6.2    Cooling section

-         Cooling trough:                      1 set

-   Cooling trough length:             4.0 m

6.3 Solid state High frequency welder(GGP300KW)

-   Nominal power: 4300kW

-   Rated DC power: Pd=360kW

-   Rated DC voltage: UdN=450V

-   Rated DC current: IdN=1070A

-   The whole efficiency: η≥85%

-   Output power: Pout>300kW

-   Designed frequency: f=200~300kHz

-   MOSFET inverter: 120kW×3

- Tank circuit output mode: no welding transformer output, secondary resonance.

-   With water-water cooler for welder

7.  Welded tube mill  CNC flying friction saw

7.1          Flying cut-off, mechanical section consist of:

-   Saw disk:           OD800mm×ID110mm×6.0mm

-   Saw waver:                     Pneumatic

-   Pipe clamp:         Pneumatic

-   Saw carriage travel: Rack and pinion with gear lath

         -        Motor for travel:     DC 30KW

-   Motor for sawing:   AC 45KW

-   Length Tolerance: 0-6mm

8.    Run-out table

8.1 Run-out system consists of:

         -        Roller conveyer 18 meter (including packing box)

-         Reversed pneumatically

-         Pushed pneumatically

9.    Weld tube mill Electric Control System

9.1          Horizontal spiral accumulator

-         AC driver.

9.2          Double DC drive and control for forming and sizing mill.

         -        DC drive,

         -        Main DC drive panel control(instrument etc.)

         -        Mill operation panel (speed adjustment, control etc).

9.3          Flying cut-off control system

         -        Saw carriage drive by DC motor 37KW,

         -        LCD operation pane

(length and batch setting ,control instrument etc).

10. Rollers

10.1        Forming and sizing Rollers material

         -        Material:   Cr12

         -        Hardness:  60 HRC +/-2

10.2 Welding rollers material

-   Material :   H13

-  Hardness:  50 HRC +/-3

• Payment Terms:

  Payment of the contract with following schedule:

  - 30%: The payment shall pay by T/T the downpayment to the Seller within 15 days after the signature of the Contract. The Contract then comes into effect.

  - 70%: The buyer shall pay to the seller 70% of total contract amount before the seller’s ship the machine to XINGANG, CHINA.

Equipment Manufacturing and Inspection/Test

1. The Seller manufactures the equipment according to the relevant standards strictly and tests the equipment according to the technical documents.

2. The Buyer shall inspect and test the commodities at the Seller’s factory at the Seller informs to confirm their conformity to the Contract Specifications. If the Buyer fails to arrive on time, the Seller shall have the right to deliver the goods according to the date stipulated in the Contract.

Technical Documents

The Seller shall submit the following documents in English:

1. Foundation Plan (including the arrangement of water, electricity and air ect.)

2. Arrangement Plan

3.Operation Instruction (including the structure diagrams of the equipment, operation instruction, maintenance and trouble shooting, safe rules, consumable parts list and purchased parts list)

Installation, Commissioning, Test and Training

1. The engineers from the Seller shall supervise the installation on site and fulfill the commissioning. They should start off within 10 days after they get the information from the Buyer.

2. The Buyer signs in the Certificate of Acceptance.

3. The Seller trains the operators of the Buyer during the commissioning

4. Commissioning: about 3 engineers in 30 days.

5. The Buyer shall pay for the international air tickets and the local, such as board and lodging, daily transportation, communication, Insurance, etc. The Buyer shall pay USD 80 /day /person to the Seller for the commissioning.

6. The Buyer shall prepare an interpreter for better communication between the two sides.