API RP 5L9:2001(2015) pdf download

API RP 5L9:2001(2015) pdf download.External Fusion Bonded Epoxy Coating of Line Pipe.
5.2.9 Add Itional Surface Treatments
Where approved by the purchaser. additional surface treatments may be used prior to application of coating. When specified by the purchaser. additional surface treatments prior to application of coating shall be performed.
5.3 COAliNG APPLICATION
5.3.1 CoatIng Equipment
5.3.1.1 Compressed Air Requirements
A source of clean, dry air with instrumentation to monitor dryness is required. The dew point of air in the fluidized bed and powder feed lines shall be no higher than — 20°F 1— 29°CJ.
5.3.1.2 Powder Filter
Adequate screens (60 mesh 1250 micron I or liner) shall be present in the powder handling system to ensure that large particles or agglomerates are not carried to the application equipment.
5.3.1.3 Coating Apparatus
Coating material shall be maintained in a lluidizcd condition during application. The apparatus used to apply the coating to the surface shall do so in a uniform manner and to the specilled thickness in a single pass.
5.3.2 Pipe Surface Heating
Pipe may be brought up to temperature by in-line furnace. soaking oven or induction coils, which have sufliciein controls to preclude exceeding the maximum allowable pipe temperature. stipulated in 5.3.2.4.
5.3.2.1 Method of Measurement
Pipe temperature prior to coating shall be monitored by means of temperature indicating crayons or other suitable means as agreed between purchaser and applicator, Coated pipe temperature may be monitored by infrared pyrometer or other suitable instrument.
5.3.2.2 Frequency of Measurement
Pipe temperature immediately prior to coating shall be monitored every 10 minutes. More frequent measurements are necessary at start-up and when there is any change in process parameters.
5.3.2.3 Coating Application Temperature
The temperature of the pipe at time of application of the coating material shall be within the minimum and maximum limits recommended by the coating material supplier.
5.3.2.4 Maximum Pipe Temperature
Unless otherwise agreed upon, pipe surface temperature shall not exceed 525°F 1274°Cl. It should be recognized that elevated temperatures may have an effect on base material (steel pipe) properties such as strength, elongation and fracture toughness, Pipe which has exceeded the maximum ternperature shall be set aside for further evaluation.
5.3.3 Powder Application
5.3.3.1 Thickness
The minimum coating thickness shall he 12 mils 1305 micronsi, unless a greater minimum thickness is specified by the purchaser. Coating thickness should be checked on eve!y pipe with an approved gauge. The gauge is to be calibrated daily, or upon purchaser’s request.
5.3.3.2 Uniformity
Coating shall be applied in a uniform manner.
5.3.3.3 Time to Quench
The minimum elapsed time between application of coating material and quenching of the pipe shall be measured and used in conjunction with the temperature measurement in 5.3.2.1 to ensure compliance with the supplier’s recommended cure schedule, for each combination of diameter and wall thickness of pipe. The tune to quench shall be monitored by means of a stop watch at start-up and &hen line speed is changed.
5.3.3.4 Recycled Powder
Thc usc of recycled powder may be permitted if adequate recovery and screening equipment is used and maintained. An adcquatc recycle system should continuously blend recycled powder with virgin powder into the delivery system. The amount of recycled powder used shall be by agreement between purchaser and applicator.
5.3.4 Coating Cutback
Suitable tileans shall be used to provide the bare steel cutback area specilied by the purchaser.
6 Production Inspection and Documentation
6.1 PURPOSE
This section describes the methods of inspection, the acceptance criteria and the documentation for pipe externally coated with fusion bonded epoxy.