FORMING SECTION  This section is composed of:

Guide roll ----------------------------------- 1 set

Side guide rolls & leveler -------------- 2 sets

Forming vertical stands ---------------- 4 sets

Forming side roll stands -------------- 3 sets

Clustered side roll stands ------------ 2 sets

Fin-pass vertical stands --------------- 3 sets

Fin-pass side roll stands -------------- 2 sets

Driving gear box -------------------------- 7 sets

GUIDE ROLL

Function:                    • Guides the strip incoming from the accumulator to the tube pass level.

Specification:

Construction:          • Two (2) horizontal steel rolls are supported by anti-friction bearings mounted on a support frame.

• This guide roll unit is mounted on the entrance side of main bed.

SIDE GUIDE ROLL & LEVELER

Function:                   • Adjusts the centerline of the strip by means of hand-wheels and screws.

• Flattens the strip to facilitate forming.

Specification:

Construction:            • Side Guide Rolls

  - The side guide rolls are provided at the entry side of forming section.

    2 Roll chocks move horizontally or centrically in a box type housing by

     a manually operated wheel and a threaded shaft, which has right and left-hand thread on it.

          - Each roll has grooved home which exactly guides and shaves sharp edges of the slit strip.

                 These rolls are made of hardened alloy tool steel to prevent from rapid weariness.

• Leveler

               - The leveler facilitates the strip entering and forming at the first stage of breakdown part.

                  Composition

  1 Heavy-duty welded steel frame

  3 Hardened and ground alloy steel rolls

  1 Height adjustment screws mounted in upper roll housing

BREAKDOWN VERTICAL STANDS

Function:                    • Forms the strip into tubular shape progressively. 

Specification:

Operation:                 • The strip passes between the upper and bottom roll of each stand, all these rolls

  are driven by DC motor. When changing the rolls, the operator unscrews the nuts engaged

  on the threaded end of roll shafts and pulls the outboard stand out.

Construction:           • Four (4) stands are provided. All stands are all identical which are made of cast iron.

   Each stand is composed of inboard and outboard housing. Outboard housing is moved off from

   the shafts to facilitate roll changeover.

• Rolls are mounted on the top and bottom shafts, which are driven by DC motor through

  universal joints and gearboxes, and are positioned at the right center by the spacers.

• In the cap of the stand, a set of manually operated single point screw jack is provided to move

  the upper roll for height adjustment.

• Heavy-duty taper roller bearings mounted in inboard stand carry the shafts and roller

  bearings rotating in hardened sleeves are mounted in outboard stand.

                                          • In front side of each stand, precisely graduated scale is provided for operator's convenience.

FIN-PASS VERTICAL STANDS

Function:                  • Finally forms the strip into open-seam round tube and keep it in upright position.

Specification:

Construction:           • The same as forming stands but fins are provided between 2 pieces of the upper rolls to

  guide the open seam to center position and three (3) stands are provided.

FIN-PASS SIDE ROLL STANDS

Function:                  • The side rolls in both sides hold the strip tightly to maintain the formed

shape and prevent the spring back of the edges of coil.

Specification:

Construction:          • The side roll stands of fin-pass part are the same as them of breakdown part.

SEAM GUIDE

Function:                    • Finally centers and maintains required gap of both edges of the strip just before welding.

Specification:

Construction:          • The main housing of the seam guide made from welded steel is mounted on the main bed.

• 2 Intermediated plates are mounted on the main housing and are adjusted in line flow

   and perpendicular directions respectively. The roll holders provided on upper and lower side of

   the tube adjust the open seam by means of worm and worm wheel, which is machined on

   the circumference of the roll holder. The upper roll is provided with fin for guiding the seam and

   the lower roll without fin supports the bottom side of the tube.

• Each roll is mounted in a chock respectively, which is moved in vertically machined roll holder.

 The seam guide main housing is adjusted in both directions of the pipe flow, forward

 and backward, thus enable to adjust exact gap for welding.

HIGH FREQUENCY WELDER ( Out of scope of supply)

SQUEEZE ROLL

Function:                    • Squeezes precisely both edges of the strip which have been heated by the welder.

Specification:

Construction:            • Both edges of the strip completely formed in tubular shape is squeezed precisely and laterally    by 3 guide rolls.

• Three (3) guide rolls are mounted on the specially made lathe chuck type holder,

  of which 3 slides are simultaneously operated with single point mechanism.

• This lathe chuck type squeeze roll holder slides vertically in the welded steel structure frame    for pass-line adjustment.

• Because of one (1) holder comprising all 3 rolls with heavy-duty roll brackets,

  roll shafts would not to be bent passively caused by spring back of the strip.

IRONING ROLL STAND

Function:                    • Thickens the welded seam of tube outside after the bead is removed.

Specification:

Construction:            • The function and construction are the same as the forming stands. 2 roll shafts are all idle.

SIZING 2-ROLL VERTICAL STANDS

Function:                     • Finalizes the size and roundness of the tube.

Specification:

Construction:          • Two (2) stands with horizontal shafts are provided.

• The functions and construction are the same as the fin-pass stands.

SIZING SIDE STANDS

Function:                   • Holds the tube tightly to maintain the formed shape.

Specification:

Construction:           • Two (2) Stands are provided. Each stand is positioned between 2 sizing vertical stands.

  Other features are the same as the fin-pass side cluster.

SIZING 4-ROLL VERTICAL STANDS

Function:                    • Shapes the round tube into square or rectangular.

Construction:

• Three (3) Stands are provided.

• Except side roll chocks, which are incorporated in the 4-roll vertical stands,

  other function and constructions are the same as 2-roll vertical stand.

• Side roll chocks are operated horizontally and vertically through manually operated screw.

TURKS HEAD STANDS

Function:

• Straightens the tube when it leaves the sizing stand.

Specification:

Construction:          • One (1) stand are provided, which are fabricated with heavy-duty steel structure.

• The No.1 turks head stand is composed of four (4) rolls on both entry and exit sides.

   By the turks head arrangement, the tube can be straightened without additional  straightening machine.

• Each four (4) rolls are vertically and horizontally adjusted by manually operated screws and

   are turned by worm and worm wheel. All rolls are idling on the roll shaft.

CUT-OFF SECTION

501. FLYING CUTOFF MACHINE

Function:                   • Cuts to length the tube by means of circular saw blade and DDS system.

Specification:

Description:

• The flying cutoff machine is of full automatic operation.

   The carriage, which is driven by DC servomotor, is traveling at the same speed as the tube

   coming out from the sizing mill. The tube is clamped by pneumatic cylinder and cut by rotating saw,

   which moves down from the top side of the tube by pneumatic cylinder.

• The carriage returns to home position at higher speed than the traveling speed for cutting.

  The saw blade is driven by AC motor, and is mounted on the carriage. DDS system accurately

  controls the cut-to-length.

Construction:           • Fixed base equipped with 2 rails on it and made of welded steel

• Mechanical stopper provided on the fixed base for emergency

• Traveling carriage provided with 4 wheels

• 4 Guide wheels mounted on the carriage

• Precision rack and pinion driven by DC servo motor

• Circular cold saw blade driven by AC motor is swung by pneumatic cylinder

• Pneumatically operated 2 clamps are mounted very closely to the saw blade

ELECTRICAL EQUIPMENT FOR TUBE MILL LINE

GENERAL CONDITIONS

Design standards    All equipment and work covered herein including design, fabrication, testing, ratings,

etc. will comply with the applicable sections of current editions of the following codes and standards.

 KS Korean Industrial Standards.

 IEC International Electrotechnical Commission

Electrical subcontractor(Supplier) All specified electrical equipment and process control systems will be based on the following

                                     subcontractors (suppliers)

- Power and drive systems

- Process automation

* PLC and subsystems maker LG

Engineering for power and drive systems will be done by subcontractor, engineering and software for process control will be carried out by Wonjin Industrial Co., Ltd.

Network conditions Power supplies will be designed based on the following nominal voltage levels :

AC power :

- Low voltage To be recommended by the Buyer ; 50 Hz ± 1 Hz , 3 Phases, 4 wire

- Short circuit level 30KA

AC power :

- Control source volt. 220 V AC

- Solenoid valves 220 V AC

Site conditions          All electrical equipment and apparatus will be suitable, both electrically and mechanically, for industrial service.

Operating conditions :

- Temperature

In electric rooms + 5℃ to +35℃

In control rooms + 5℃ to +30℃

Outside of rooms - 5℃ to +40℃

- Humidity Max. 80 %

- Altitude Max. 1,000 m

LINE DRIVE

Variable speed DC drives DC motors will be separate excitation or permanent magnets. All motor are of industrial design

                             for use under rough industrial environmental condition.

The rating of all motors is in accordance with IEC.

- Rated power Acc. to requirements

- Design of protection Drip proof self ventilated IP23S

- Cooling IC 06

- Rated voltage xxx V, 3-phases

- Armature voltage xxx V

- Rated speed Acc. to requirements

- Insulation Class F

- Mounting Foot mounted B3

- Bearing Ball bearings

- Accessories Temperature sensor (thermostat)

- Overload capacity 150%, 1 min

Equipment to be provided One (1) lot,

Speed controllers for DC motor

The double bridge three phases variable speed controllers are designed for the speed regulation

of 2.2 to 1,300 kw DC motors with separate excitation.

Characteristics

- The speed controllers enable operation in all 4 quadrants of the torque/speed range.

- From the 800A rating upwards, it is fitted with a field current regulator.

Speed range

- Regulation by armature voltage accuracy 1 to 20

- Regulation by tachogenerator accuracy 1 to 300

- Regulation by incremental encoder accuracy 1 to 3000

Acceleration and deceleration ramps

- Acceleration and deceleration independently adjustable from 0 to 999.9.

Reversal

- Solid state reversing in all 4 quadrants

Braking

- By regenerative braking

Speed variable AC motors

AC motors will be squirrel cage induction type. All motors are of industrial design for use under

rough industrial environmental condition

The rating of all motors is in accordance with IEC.

- Rated power Acc. to requirements

- Design of protection Totally enclosed IP 54

- Cooling Surface cooled with shaft mounted

fan IC 0141 or independent fan

IC 0641 acc. to requirements.

- Rated voltage xxxV, 3-phases

- Rated frequency 50 Hz

- Rated speed Acc. to requirements

- Insulation Class B, temperature rise B

- Mounting Foot mounted B3 Flange mounted B5 or as indicated.

- Housing material Cast iron otherwise welded

- Bearings Ball bearings

- Accessories Gears (if required)

- Overload capacity 150 % , 1 min

Equipment to be provided

- One (1) lot, AC motor according to motors and components list.

Speed controllers for AC motors

The system consists of individual inverter units each connected to the AC motors.

Power technology

Diode bridge with high Ⅰ²t

- Rugged to withstand harsh environments

Inverter : 2.2 to 7.5 kW - IPM - Intelligent Power Module

= IGMT + integral protection 11 to 220 kW - IGBT

- Significant increase in product reliability

- Reduction in switching losses

Switch mode power supply

- New functions

- Rugged to withstand harsh environments

Isolated power and control

(high impedance isolation used for measurement of supply voltage and DC bus voltage)

- Solution providing simplified EMC conformity

(Electro Magnetic Compatibility)

Control technology

High level of integration

Significant reduction in the size of the control card

- AISC

One use for digital functions ; Motor control, PWM generation, detection of tripping faults

One use for analogue functions ; Management of analogue inputs, measurement of

                                             motor voltage

- Surface mount technology

- Multilayer circuits (4)

Designed for high MTBF

- 16 Bit micro processor, 40 MHZ, 100ns average cycle time, pipeline architecture

Functions; Calculation of regulation algorithm, monitoring, faults.

I/O management, man-machine dialogue.

- Real-time kernel for a "product" and "option" software structure.

- Plug in customer connectors.

- Communication cards and dedicated PCMCIA cards

(Personal Computer Memory Card International Association)

- IP 20 cards (Protected against finger contact)

Drive parameter programming and diagnostics

Each drive will include a drive-related operation graphic terminal.

- 64 x 128 pixel, ie 6 lines of 21 characters

- LCD screen (40 x 70 mm)

- Back list screen

- 20 keys

Fixed speed AC drives

AC motors will be squirrel cage induction type.

All motors are of industrial design for use under rough industrial environmental conditions.

The rating of all motors is in accordance with IEC.

- Rated power Acc. to requirements

- Design of protection Totally enclose IP 54

- Cooling Surface cooled with shaft mounted fan, IC 0141

- Rated voltage xxxV, 3-phases

- Rated frequency 50 Hz

- Rated speed 1200, 1800 rpm

- Insulation Class B, temperature rise B

- Mounting Foot mounted B3 Flange mounted B5 or as indicated

- Housing material Cast iron otherwise welded

- Bearings Ball bearings

- Accessories Gears (if required)

Equipment to be provided

- One(1) lot, AC motor according to motors and components list

Motor control centers

Switchgear for motor starters and feeders as required for the installed auxiliary AC drive

equipment and other consumers.

The AC switchgears will be complete in all respects, pre-assembled and ready for installation

and connection.

Included are all indicating equipment, actuators, protection and control equipment.

Design

Indoor design, closed cubicles for single or double fronted arrangement, equipped with starter

comprising all electrical devices such as fused isolator switches, contactor,

hermal overload protection, motor protection units, individual control voltage transformers and

relays.

Cable connection from the bottom.

- Nominal voltage xxxV, AC

- Rated frequency 50 Hz

- Short circuit 15 KA

- Control voltage 220V, AC

- Enclosure IP 41

Equipment to be provided

One(1) lot, MCC's according to plant requirement incl. incoming feeder panels with load

break switch.

PROCESS CONTROL SYSTEM

The purpose of this specification is to define the process control system as required by this line.

The proposed programmable controllers, microcomputers and standardized stand-alone control systems

are a reasonable system selection based on the process needs.

Hardware unification is widely achieved by proper selection and design of the applied systems, thus to minimize

costs for maintenance and spare parts.

Hardware features

PLC-systems

- Marker LG or equivalent

- Processor 16 bit or 32 bit

Analog input

The system scans and converts to digital form, analog signals resenting temperature, pressure,

flow, lever and other process measurements.

Five types of module cover the analog requirements of the majority of industrial application,

- 4 Isolated high-level channels (voltage or current)

- 4 Isolated low-level channels (thermocouple or low level voltage)

- 4 Isolated low-level channels (pt 100 probe or low level voltage)

- 8 Isolated high-level channels (voltage or current)

- 8 Fast high-level channels (voltage or current)

Analog output

Analog outputs for control will have 12-bit resolution D/A converters.

Output is generally 4-20 mA isolated.

Digital input

The system is capable of scanning on sufficient scanning rate every digital input representing

status information.

All contacts used as inputs for control functions will be scanned either immediately before

use or in a manner that ensures updated information.

Each digital input will be filtered for contact bounce and isolated.

- Input voltage 110V AC, 24V DC

Digital output

Low speed discrete output modules will be potential isolated.

Status indication is provided.

Discrete outputs will be suitable for directly energizing and de-energizing motor starter

magnetic coils or relays and solenoid valve. Each output will be fused and will have status

indication.

- Output voltage 220V AC, 24V DC

Special Input/Output

For processing of encoder signals, etc. high-speed counter modules will be used.

Spare capacity

The control system includes 15 percent built0in spare capacity of used I/O's to allow for

contingencies and future expansion. This includes I/O, terminations, rack space, memory,

and programmable function blocks.

System communication

Data exchange is, by the use of a digital communication interface between the controller systems.

Flying master or token passing principle for communication will be applied.

Subsystem communication

Data exchange is, by the use of a digital communication interface based on a point-to-point

connection.

Alternatively parallel interfacing might be supplied if efficient.

System Software

The programmable controller system software will support either relay ladder diagram, functional

block programming or fill in the blanks, normally open, normally closed, transitional, and latched

ontacts, timer, counters, 4-function arithmetic, shift register, comparisons, interrupts, closed loop

control, skip, ASCII reading/writing, subroutines, shall be supported as far as required.

Panels of equipment

Main panel

- AC panel (including P.L.C.) Controls AC motors, Solenoid valves and sensors etc.

- DC panel Controls DC motors.

Operation panel

- Entry part

- Main

- Flying cutoff machine(DDS)

Line automation function

Line handling and monitoring

- Line set-up

- Line coordination (plant switch on sequence, mode of operation etc.)

- Alarming

Line drive master control

- Speed referencing / control

- Jogging

- Running

- Automatic slow-down

- Acceleration / deceleration

- Drive interlocking and sequencing