SSPC PA 8
Thin-Film Organic Linings Applied in New Carbon Steel Process Vessels
|Publication Date:||15 March 2003|
Procedures detailed in this recommended practice shall be followed during the design, installation, and inspection of a thin-film (500 μm [20 mils] or less) organic lining in process vessels to maximize the service life of the process vessel.
A thin-film lining material must be carefully evaluated for use within a process vessel. The evaluation must be based upon consideration of the process stream constituents, temperature, pressure, and other factors. An important consideration is the end use for the process-vessel lining- a corrosive or noncorrosive service. Usually, a lining that has long-term service and experience in similar process conditions is selected.
Fabrication of the vessel must be suitable for lining application including surface preparation, application, and curing. Fabrication details are influenced by the service-corrosive or noncorrosive.
Dehumidification is desirable during the entire installation process because it achieves climate control during surface preparation and lining application. When dehumidification is employed, the lining application can be carried out without interruption, avoiding possible contamination by blasting debris.
The lining may be cured at ambient temperature or heat cured at an elevated temperature. It can be applied in the shop or at the work site. The lining must be applied according to the lining manufacturer's instructions, unless superseded by the direction of the owner.
When heat cured, instrumentation must be installed to determine the time and external metal temperature during the lining curing cycle. When applied and heat cured at the work site, the vessel shall be thermally insulated to provide uniform heat retention. Particular attention should be paid to heat sinks, such as vessel supports, ladders, and other attachments
If piping, nozzles, or other appurtenances are to be abrasive blast cleaned and lined, proper equipment must be available.
All applicable safety regulations shall be followed during all phases of surface preparation, application, inspection, and curing.
Thin-film organic linings are not generally used when the process operating temperature exceeds 120°C (250°F). Also, if exposed in environments that cause excessive corrosion, the vessel's corrosion allowance, or internal inspection frequency, may require reevaluation. (See Paragraph 3.6.)
Appendix A contains a listing of all documents and standards used in conjunction with this recommended practice.
The lining manufacturer's technical data sheet, material safety data sheets (MSDS), and application and curing instructions shall be used in conjunction with the documents listed in Appendix A and the requirements contained within this recommended practice.
Any conflict between documents shall be resolved by the owner.
During all phases of the vessel lining installation, inspection shall be conducted by the lining applicator and, when appropriate, by the owner's inspector. (See Section 8.)
The applicator shall record all pertinent information concerning the vessel lining installation within the NACE Coating Inspector's Logbook1 or equivalent, as approved by the owner. This logbook shall be available to the owner's inspector at all times.