SUPPLY AND APPLICATION OF COATINGS
Corr-Rad supplies and provides application services for hot and cold applied pipeline coatings. Corr-Rad is also marketing anti-corrosive tapes of the highest standards.
Hot-Applied Coatings
Cold Applied Tape Coatings
Heat Shrink Sleeves for welded joints
HOT APPLIED COATINGS
Coal Tar Enamel / Fiber Glass Tissue Coating & Wrapping.
Conventional hot applied coal tar enamel coating with fiberglass wrapping
Coal Tar Tape Coatings.
Coal Tar based tape is highly recommended because of its high insulating properties. Also being an inert material it is resistant to corrosive chemicals and also due to its water repellant properties it gives excellent corrosion protection to pipelines
Bitumen Based Tape Coatings.
Bitumen based tape coating material is a cheap method of giving a coating. It is generally not recommended because of it’s poor performance by not giving corrosion protection.
COLD APPLIED TAPE COATINGS:
System components: The prefabricated polyolefin tape coating system shall at least three layers consisting of the following:
- A liquid adhesive layer.
- An inner-layer tape for corrosion protection.
- An outer-layer for mechanical protection.
The inner-layer tape and outer layer tape are made of prefabricated tapes in rolls. The properties of the entire system conform to the values listed as in tables A, B, C and D.
Liquid adhesive:
The liquid adhesive consists of a mixture of suitable rubber and synthetic compounds and a solvent. The liquid adhesive shall be applied to the properly prepared pipe surface before application of the inner layer tape. The function o the liquid adhesive is to provide a bonding medium between the pipe surface and the inner layer tape.
Inner Layer Tape:
The inner layer tape shall be a two layer tape consisting of a polyolefin backing layer with a laminated butyl-based adhesive layer. The inner layer tape shall be applied after the liquid adhesive and before the outer layer tape. The primary purpose of the inner layer tape is to provide corrosion protection
Outer Layer Tape:
The outer layer tape shall be a two / three layer tape consisting of a polyolefin backing layer with a laminated butyl adhesive layer. The primary functions of the outer layer tape shall be providing mechanical and outdoor weathering protection to the tape system.
Coating System Thickness:
The total thickness of the system consisting of inner layer tape and outer layer tape may vary, depending on pipe diameter, operating conditions, and installation conditions. In some cases, more than one application of inner layer tape and outer layer tape may be used. The total thickness and combination of the various layers used is discretionary with the purchaser, with proper consideration given to the manufacturer’s recommendations. However, in no case shall the thickness be less than those stated in tables B, C, and D.
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Table A. Properties of Primer |
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| Color | Base | Weight | Flash Point |
| Black | Rubber and synthetic resins | Flammable – 0.72-0.96 Kg/L | (-17°C) or greater |
| Nonflammable – 1.20-1.44 Kg/L | none | ||
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Table B. Properties of Inner-Layer Tape |
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| Description | Minimum | Maximum |
| Width Deviation | (-)5% or 1/4 in. (6mm) | (+)5% |
| whichever is smaller | ||
| Thickness (20 mil (508 µm)} nominal | 19 mil (483 µm) | 22 mil (559 µm) |
| Ratio of adhesive to total inner layer tape thickness, t | 40% of total t | 60% of total t |
| Adhesion to prepared steel | 200 ozf/in. width | |
| Water absorption (24 h) | – | 0.2% by wt. |
| Water- vapor transmission percent by weight | 0.2 perms (1.15 x 10-11 g (Pa.s.m²) | |
| Dielectric strength | 6000 V/single thickness | |
| Insulation resistance | 500,000 megohms | |
| Tensile Strength | 20 lbf/in. width | |
| 3500 N/m width | ||
| Elongation | 100% | |
| Nonpolyolefinic material percent by weight | 1.00% | 3.50% |
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Table C. Properties of Outer-Layer Tape |
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| Description | Minimum | Maximum |
| Width Deviation | 5% or 1/4 in. (6mm) | 5% |
| whichever is smaller | ||
| Thickness (30 mil (762 µm)} nominal | 27 mil (686 µm) | 33 mil (838 µm) |
| Adhesion to inner layer | 20 ozf/in. width (200 N/m width) | |
| Tensile Strength | 40 lbf/in. width (7000 N/m width) | |
| Elongation | 100% | |
| Nonpolyolefinic material percent by weight | 3.00% | 7.00% |
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Table D. Properties of Total System |
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| Description | Minimum | Maximum |
| Thickness | 5% or 1/4 in. (6mm) | 5% |
| 50 mil, nominal | whichever is smaller | |
| 80 mil, | ||
| Thickness (30 mil (762 µm)} nominal | 27 mil (686 µm) | 33 mil (838 µm) |
| Adhesion to inner layer | 20 ozf/in. width (200 N/m width) | |
| Tensile Strength | 40 lbf/in. width (7000 N/m width) | |
| Elongation | 100% | |
| Nonpolyolefinic material percent by weight | 3.00% | 7.00% |
