ON
LINE PROCESS CONTROL
To ensure a defect free surface and consistent
welding in the tubes produced by High Frequency Induction
Welding, on line process control is exercised as detailed:
1. Raw Material Stage
Every coil is inspected for thickness &
width and samples for Mechanical properties and chemical analysis
are taken for testing & sizes are verified physically
as per order/marking.
2. Slitting Stage
Every slitted coil is physically measured
for thickness & width. Proper identification of each coil
with details of correlation before use is being carried out
by pasting stickers.
Visual inspection for laminations, cuts pits
& seams is being carried out apart from edge conditions
for Burrs & deep scratches.
3. Tube Mill Stage
On line process control is exercised physically
to monitor:
a) Thickness
b) Outside Diameter
c) Length
d) Bend/Flattening Test
e) Visual inspection for lamination over lap, open seams,
butt weld pits, Roll marks, Double/Taper cutting, proper head
cutting, inside head formation etc.
4. End Cutting Stage
Visual inspection for each pipe is carried
out. The facing should be square without burrs or beveled
as per requirement.
5. Hydrostatic Pressure Test
Each pipe is tested for no leakage at 51Kg/cm²
for 3 seconds as per BIS standards which may vary as per requirements
of the code..
6. Threading
a) Each & every pipe is checked with
suitable screw ring guage looseness/tightness of threads.
b) Defects like sharpness, Double threads, centreout of threads,
burning Marks and impression of threads inside the tube are
visually inspected.
7. During Galvanising
a) Conformity to proper thickness & uniformity
of Zinc coating on pipes.
b) Marks of Zinc coating.
c) Proper Batch no. is marked for identification.
d) Defects like Roughness, Black spots, bore patches, pimples,
lumpiness, bulky white deposits and blisters are watched during
the process and controlled.
8. Final Inspection
a) Visual inspection
b) Class identification by colour coding
c) Physical checking on random sampling for
- Thickness
- O.D.
- Length
d) Alignment of threading and its protection
caps.
e) Checking of Bundling as per customer’s requirements.
9. Inspection by 3rd party
In case of any requirements of 3rd party
inspection of the Buyer, the same are carried out prior to
dispatch
Steel Strip
Size for Pipe & Tubes Produced
| Sr.
No. |
Thickness
Pipe Size |
2mm |
2.3mm |
2.6mm |
2.9mm |
3.2mm |
3.6mm |
4.0mm |
4.5mm |
4.8mm |
5.4mm |
| 01 |
15mm
0.5Inch |
64
L
1.84 |
--- |
63
M
2.34 |
---- |
|
--- |
--- |
--- |
--- |
--- |
| 02 |
20mm
0.75Inch |
--- |
84
L
2.116 |
83
M
2.116 |
---- |
|
--- |
--- |
--- |
--- |
--- |
| 03 |
25mm
1-Inch |
--- |
--- |
101
L
2.392 |
---- |
|
--- |
|
--- |
--- |
--- |
| 04 |
32mm
1.25Inch |
--- |
--- |
129
L
2.392 |
---- |
|
--- |
|
--- |
--- |
--- |
| 05 |
40mm
1.5-Inch |
--- |
--- |
--- |
148
L
2.668 |
|
--- |
|
--- |
--- |
--- |
| 06 |
50mm
2.0-Inch |
--- |
--- |
--- |
184
L
2.668 |
--- |
|
--- |
|
--- |
--- |
| 07 |
65mm
2.5-Inch |
--- |
--- |
--- |
---- |
|
|
--- |
|
--- |
--- |
| 08 |
80mm
3.0-Inch |
--- |
--- |
--- |
---- |
|
--- |
|
--- |
|
--- |
| 09 |
100mm
4.0-Inch |
--- |
--- |
--- |
---- |
--- |
|
--- |
|
--- |
|
| 10 |
125mm
5.0-Inch |
--- |
--- |
--- |
---- |
--- |
--- |
--- |
|
|
|
| 11 |
6.0-Inch |
--- |
--- |
--- |
---- |
--- |
--- |
--- |
|
|
|
|
