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Coatings
Ductile
iron pipes : Electrosteel offers ductile iron pipes, metallic zinc sprayed, with a
finishing layer of bituminous paint (with fillers).
| Applicable
Standards |
:
|
ISO 8179 :
1995 PART – I
BS EN 545 : 2002
BS 3416 : Type 2
IS:8329 IS:9523 |
Ductile iron
fittings : Electrosteel offers ductile iron
fittings, externally coated with zinc rich paint and
finishing layer of bituminous paint (with fillers).
| Applicable
Standards |
:
|
ISO 8179 :
1995 PART – 2
BS EN 545 : 2002
BS 3416 : Type 2
IS:8329 IS:9523 |
Field
of use, characteristics of soil : Ductile iron pipes and fittings
supplied with the above mentioned external coatings can be buried in contact with majority of
soils. For special type of soils, as mentioned below, additional and / or special coatings are
recommended.
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- With a low resistivity, less than 1500 ohm – cm above the water
table or less than 2500 ohm – cm below the water table.
- With low pH, below 6,
- With contamination by certain wastes, organic or industrial effluent.
- Stray currents.
Special
coatings : Other special type of external
coatings can be supplied as mentioned below :
- Zinc
coating with extra thickness.
- Coal tar coating.
- Bitumen pigmented with materials
for high temperature.
- Epoxy coating.
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Linings
Ductile
iron pipes : Electrosteel offers internal cement mortar lining, centrifugally applied
as per the following standards :
| Applicable
Standards |
:
|
ISO 4179 :
1985
BSEN 545:2002
IS:8329 IS:9523 |
The thickness is maintained
as per the following table :
DN (mm) |
Thickness (mm) |
Nominal Value |
Tolerance |
80 - 300. |
3.5 |
-1.5 |
350 - 600. |
5.0 |
-2.0 |
700 - 1100. |
6.0 |
-2.5 |
Ductile iron fittings
: Ductile iron fittings are also supplied with internal cement mortar lining.
| Applicable
Standards |
:
|
BSEN 545:2002
ISO 2531 : 1998
IS:9523 2000 |
The type of cement used for
internal lining, that can be supplied are :
- Sulphate resistant Portland cement.
- Blast furnace slag cement.
- High Alumina cement.
Cement mortar
lining
Recommended Types
Of Cement
| Water Characteristics |
Ordinary
Portland Cement |
Sulphate Resistant Cement |
High Alumina Cement |
| pH Minimum Value |
6.0 |
5.5 |
4.0 |
| Maximum Content (mg./l.) |
| Aggressive CO2 |
7 |
15 |
No Limit |
| Sulphates (SO4-) |
400 |
3000 |
No Limit |
| Magnesium (Mg
++) |
100 |
500 |
No Limit |
| Ammonium(NH4+) |
30 |
30 |
No Limit |
Advantages
of cement mortar lining :
- As a corrosion protection, cement mortar lining is an added advantage to ductile iron
pipes. The lining provides a physical as well as chemical barrier to corrosion of the iron wall.
- Eliminates red, rusty water and tuberculation.
- For soft water a seal coat over cement lining reduces leaching effect.
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Special
types of linings : The following types of special linings are also offered :
- Cement mortar lining with bitumen seal coat.
- Cement mortar lining with epoxy seal coat.
- Bituminous paint.
- Two pack Epoxy.
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