All pipes shall be delivered to the coating applicator bare. Because removal of old coatings may not be possible, the intent of this specification is that the entire exterior of the ductile iron pipe or fitting shall not have been coated with any substance prior to the application of the specified coating material.
NAPF 500-03-04 (2.1- Abrasive Blast Cleaning- External Pipe Surfaces). The entire surface to be coated shall be abrasive blasted. The intent of this specification is that 100% of the surface be struck by the blast media so that all loose oxides, rust, and other substances interfering with adhesion are removed.
Coating of Pipe
After surface preparation and within 12 hours of surface preparation the entire exterior surface up to the gasket groove, with the exception of the spigot end, shall receive an average of 25 mils, 20 mils minimum, of Ceramapure PL-90 Epoxy. If any rusting is apparent prior to coating the surface, the entire area must be re-blasted as specified.
Coating of the Spigot Ends
Due to the tolerances involved, the spigot end from the gasket area to the end of the spigot must be coated with 6 mils average, 10 mils maximum of Ceramapure PL-90 Epoxy. Care should be taken that the Ceramapure Epoxy is smooth without excess buildup on the spigot end.
Testing of Coating
- The film thickness of the coating shall be checked using a magnetic film thickness gauge. Measurements shall be taken per SSPC PA2 Section 5.1.
- The coated areas of the pipe from the socket edge area of the spigot back to the bell face shall be tested for pinholes using a 2000 volt pinhole detection test. Any pinholes found shall be repaired prior to shipment.
Any areas where damage has occurred due to handling shall be repaired using Ceramapure PL-90 Epoxy prior to installation to equal the original coating.
All pipes shall be handled with belt slings and padded forks to avoid damage. All shipping timbers and straps should be padded when shipping pipe.
Because the specifications for application and testing of Ceramapure PL-90 Epoxy have been developed for pipe using test data and performance history, no deviations from the specification shall be permitted without prior written approval of the lining manufacturer. If required, third party inspection of Ceramapure PL-90 Epoxy shall be done only after written notice to the applicator of Ceramapure PL-90 Epoxy. Any third party inspection shall be accomplished using Standard Ceramapure PL-90 Epoxy Quality Control Procedures and shall take place at the application facility.