Sr. No. |
Cement Mortar
Lined Ductile Iron & Mild Steel Pipes. |
HDPE Coated &
Lined Pipes |
1. |
There is no bonding betwen Mild Steel surface and cement
mortar lining.
|
HDPE lining & coating are fusion bonded and there is
very high bonding between Mild steel surface and HDPE
coating & lining.
|
2. |
Since cement mortal lining are thick, the over all
inside diameter reduces and hence the carrying capacity
of the pipes and reduced considerably.
|
HDPE coating & lining are applied in microns and there
is no reduction in the inside diameter.
|
3. |
Cement being alkaline and in contact with water,
provides increased pH. Corrosion is pH dependent, higher
pH, lower the corrosion. However, if the alkalinity of
the cement is reduced, for example by some chemical
reactions, the pH goes down and the cement lining fails.
Cement lining failures have been analyzed and one of the
main cause is the leaching of the calcium hydroxide from
the cement lining.
|
HDPE coating & lining are chemically inert and thus they
are permanent, can resist pH values from 0 to 14.
|
4. |
Product Attributes:
Lining thickness -6mm to 25mm
|
Coating / Lining thickness - 1mm to 3mm
|
5. |
Performance Attributes:
Adhesion to Steel
ASTM D 4541 - 0 psi
|
Vacuum test - 700 mm Hg (no disbonding)
|
