Now we come to the term “Tank life”. Once the containers of Met-L-Chek Company products have been opened, shelf life no longer applies. If the product is in a tank or other container where it is used, the term “tank life” applies.
For example, if a penetrant has a shelf life that expires on January 6, for example, and the penetrant was charged to a tank prior to that date, the product is OK to use. When January 6 has passed, the shelf life date has no meaning because the product is in a tank. Now “Tank life” is what counts. Continued usability of materials may be verified through the Met-L-Chek Company Pen-Chek® or MagChek™recertification program. The Pen-Chek® program conforms to the requirements of AMS-2644E and ASTM E-1417. The Mag-Chek™ program conforms to the requirements of ASTM E-1444. For some applications, there are penetrant tanks that have Met-L-Chek products in them that are five or more years old. The monthly tests show that the material is satisfactory to use, and there is no reason to discard the material and to replace it with fresh product. The distinction between “Shelf life” and “Tank life” is important to make. For Met-L-Chek products that are in a tank and in use, there is no reason to discard the product and to replace it with fresh product if the shelf life has passed. Shelf life has no further meaning once the product is in the tank. This information is on the Met-LChek ®web site and may be easily reviewed there. Or, for clarification, please send us an email or phone us.