|
For More Info Call:
800-882-5543
John Tracy x. 3806 |
|
Coatings: What do they do for our
products?
Coatings add to the life of our products by providing longer
durability against normal environmental corrosion. Coatings improve
the appearance of the tubing, and they prepare the tube surface for
specific end uses.
What is so special about Allied's coatings?
The technology and the process of carbon steel tube and pipe
manufacturing are well known to the hundreds of manufacturers across
this nation and in other countries. But what makes Allied so special
is our ability to combine the following two functions with a high
degree of success. Developing unique coating systems/formulations
specially for Allied's products and processes. Developing
unconventional coatings application equipment and techniques to
facilitate continuous on-line coating application and curing
operations at high line speeds.
Exterior Coatings Classifications
Unless otherwise specified by a customer, almost all of our galvanized
tube and pipe is triple-coated externally by using the following three
sequential processes:
- Galvanizing (zinc coating)
- Conversion coating (for
passivation film)
- Clear organic polymer application
- Zinc Coating
Galvanizing
Allied uses special
high-grade quality zinc for its galvanizing operation. Our zinc is
99.99% pure and contains only a trace amount of lead. Hot-dipped
galvanized pipe or pipe made from pre-galvanized steel coils normally
use Prime Western grade zinc and other grades which contain a high
level of lead, sometimes more than 1% by weight.
Conversion Coating
The conversion coating over the galvanized surface is formed due
to a chemical reaction and this film becomes an integral part of the
superficial layers of the zinc coating. The film passivates the highly
reactive zinc surface and retards the formation of white rust by a
substantial margin. Also, the conversion film enhances bonding or
adhesion of any additional paints or coatings applied over the
galvanized surface. For small mechanical tube, where a silver bright
type of surface is more desirable for some of our customers, a minimal
amount of the conversion coating is applied for short-term indoor
storage purposes. For the relatively larger diameter pipe, a heavier
coat is applied.
Clear Organic Polymer Coating
The clear organic polymer coating is applied as a third coat or
final finish on the exterior surface. This final layer acts as a
barrier coating and further reduces the atmospheric corrosion of the
product. However, there is an interesting phenomenon that occurs as a
result of the combination of the second and third coating. Combined
performance (corrosion protection of these two coatings) is more than
the summation of the individual protection provided.
Zinc Interior Coatings
We have a number of ID (interior diameter) zinc coatings which
have been specially formulated to meet specific customer fabrication
requirements. We are continuously upgrading our ID coatings to
maximize the overall corrosion resistance of the interior of the tube.
All our ID coatings are applied after the tube is welded...thereby
assuring a uniform coating on the entire interior surface. In
addition, none of our ID coatings will contaminate paint or powder
coat cleaning systems. |
|
