Raw Materials Analysis
To assure conformance to Allied's high standards, rigorous quality tests (including wet chemical, physical and instrumental methods of analysis) are performed on incoming materials. Instrumental techniques utilized for the qualitative and quantitative evaluation of coatings and solvents include atomic absorption spectrophotometric elemental analysis, infrared spectrophotometry and gas chromatography. The quality steel used in the manufacture of Allied's structural/mechanical tube meets ASTM A-569. The zinc spelter conforms to ASTM B-6 High Grade and Special Grade Zinc.
The success of structural design is related to the mechanical properties of the base materials; the determination of these properties is one of the most important phases of our quality assurance program.
The bending strength is determined by applying a concentrated load on a freely supported tube specimen. The continuously applied load is electronically plotted, and the total and permanent deflections are determined by an offset method. The evaluation of the ability of a tube to withstand this mode of loading is a direct measure of performance.
Electron and optical microscopy are used as a highly sophisticated quality tool whereby we apply metallurgical principles to our manufacturing process to achieve the proper combination of metal structures and properties.
A coatings quality assurance program was developed to insure high quality. Preshipment samples are examined for viscosity, color, cure rate and solids content prior to receipt of new batches. An ongoing record of salt spray and weatherometer results are maintained and compared to incoming quality assurance results. Changes in specifications occur as required to maintain the high quality of Allied's coatings. All OD polymeric coatings utilized are lead-free, and meet the toxicity standards of the Consumer Product Safety Commission.
Weathering resistance of OD coatings is evaluated using a xenon light source (ASTM G-26). Random samples are subjected to alternate exposure of ultraviolet light and darkness at controlled temperature and humidity. Samples are examined at regular intervals 1000 hours of exposure are evaluated.
Salt Spray Testing ASTM -B-117°
OD and ID corrosion resistances are monitored on an ongoing basis using salt spray testing. Random samples are prepares and exposed to 5% salt fog at 95°. These samples are examined at regular intervals until a pre-determined end point is reached. Typical end points are the first signs of white rust and first signs of red rust. Loss of coating adhesion on scribed and unscribed areas is used as additional performance criteria.
In addition, eddy current testing is available at both Harvey and Philadelphia for all pipe size equivalents. Continuous in-line laser image monitoring of weld quality is done for all pipe sizes to insure better weld quality during tube forming and welding. Our staffs of professional Engineers and Technicians are ready to react quickly to your specific end-use requirements.
Coating Resistance Test Results
Allied's coatings resist the following:
- Motor Oil
- Common Household Chemicals
- Wines, Beers, Soft Drinks, Hard Liquor
- Disinfectants (Household and Commercial Varieties)
- Meat Products
- Damage by Impact
- Citrus Products
- Detergents (Laundry and Other Chemicals)
- Sulfuric Acid 60%
- Hydrogen Peroxide 5%
- Hydrochloric Acid 30%
- Sodium Hydroxide 10%
- Ammonium Hydroxide 28%
- Phosphoric Acid 75%
- Aqueous Eosin Bluish 5%
- Trisodium Polyphosphate 30%
- *These tests were conducted in a controlled environment, and our tube was subject to these substances for a short duration of time. Tests were conducted over Allied's polymeric clear OD coating as a final finish.
- Special Note: In addition, Allied tubular products exhibit superior sunlight and temperature (variation -10°F to 120°F) resistance properties.
- Tests independently conducted by Scientific Control Laboratories, Chicago, IL in accordance with ASTM B-117. Detailed Scientific Laboratories' tests results are readily available from your local Allied Sales Representative.