1 General Provisions
1.0.1 This Code is formulated with a view to improving the process design of steel pipe coating plant, to promoting the process technology and equipment for steel pipe plants and to propelling the technical upgrading and restructuring of steel pipe coating plants in China in accordance with the national policy for iron & steel industrial development.
1.0.2 This Code is applicable for process design of new installation, revamping and expansion of external polyethylene, polypropylene, fusion bonded epoxy (FBE) coating line for steel pipes, as well as internal fusion bonded epoxy and bi-component liquid coating line for steel pipes.
1.0.3 Process design for the steel pipe coating plant installation, revamping and expansion shall comply with the national industrial policy, and achieve high quality, high efficiency, low cost and environmentally friendly.
1.0.4 Process design for the steel pipe coating plant shall comply with the current national standards in addition to this Code.
2 Terms and Symbols
2.0.1
coating
a layer of organic substance applied onto the surface of the steel pipe (substrate).
2.0.2
external coating
a layer of organic substance applied on external surface of steel pipe (substrate).
2.0.3
internal coating
a layer of organic substance applied on internal surface of steel pipe (substrate).
2.0.4
fusion bonded epoxy coating
a layer of fusion bonded epoxy substance applied on surface of steel pipe (substrate).
2.0.5
bi-component liquid coating
a layer of substance that is obtained when the bi-component organic liquid paint applied on surface of steel pipe (substrate) is cured.
2.0.6
coating material
incoming material of coating that is applied on surface of steel pipe (substrate).
2.0.7
adhesive
any substance that binds the steel pipe substrate or primer to polyethylene or to polypropylene.
2.0.8
coating line
an assembly of process equipment necessary to produce the products as specified in the product mix, covering the full process from incoming material preparation till finished product collection.
2.0.9
annual scheduled operation time
annual calendar time deducting overhaul time, medium repair time, minor repair time and normal shift take-over time.
2.0.10
annual available production time
annual scheduled operation time deducting tool changing time, size changing time and downtime.
2.0.11
annual necessary production time
production time required to achieve the annual production capacity specified in the product mix.
2.0.12
duty ratio of the line
the ratio of annual necessary production time to annual available production time of the line (in percentage).
2.0.13
consumption per unit of product
the amount of energy and utilities (electricity, water, compressed air, etc.), incoming materials and auxiliary materials consumed in producing per unit area of coating product.
2.0.14
pipe detaching
a process in coating application procedure of external coating line, which is intended to separate the external polyethylene or polyethylene coating of two consecutive steel pipes at their head-tail connection.
2.0.15
manual inspection
a method to examine the steel pipe or coating surface quality, coating thickness, etc.by eyes or tools such as magnifier, roughness tester, gauges, thickness gauge and salinity tester.
2.0.16
on-line
for a procedure in relation to the continuous steel pipe coating line, on-line refers to a mode of operation in which the work-piece (including incoming materials and semi-finished coated pipes) can be shifted from the line to the procedure or from the procedure to the line without using crane, car or manual transport.
2.0.17
off-line
for a procedure in relation to the continuous steel pipe coating line, off-line refers to a mode of operation in which the work-piece (including incoming materials, semi-finished coated pipes)can be shifted from the line to the procedure or from the procedure to the line with using crane, car or manual transport.
2.0.18
organic exhaust gas
the gas generated during steel pipe coating and containing organic components.
2.0.19
organic exhaust gas purification equipment
the equipment to remove the organic exhaust gas generated during steel pipe coating.
2.0.20
surface preparation
a process to remove the impurities generated or attached to the surface of steel pipes (substrate)prior to coating in order to improve the coating adhesion to the steel pipe substrate.
2.0.21
spray coating
a type of coating process in which the atomized coating material is sprayed on surface of steel pipe (substrate).
2.0.22
electrostatic powder coating
a type of coating process in which the atomized powder coating material is charged or polarized in high-voltage electric field so that they can adhere to surface of steel pipe (substrate).
2.0.23
annual extrusion cladding
a type of coating process in which the coating material is melt in the extruder and cladded on surface of steel pipe (substrate) as circular-shaped thin film.
2.0.24
sidewise extrusion wrapping
a type of coating process during which the coating material is melt in the extruder and wrapped onto surface of steel pipe (substrate) as strip-shaped thin film.
3 Basic Requirements
3.0.1 The type of steel pipe coating line shall be determined based on the product type, product sizes and production capacity specified in the product mix.
3.0.2 The steel pipe coating plant should be located adjacent to the feedstock pipe plant or the coated pipe user.
3.0.3 The steel pipe coating plant must not be located in residential area or in public buildings used for culture, education, medical care & health purpose, etc.
3.0.4 The steel pipe coating plant must be provided with necessary safety & hygiene facilities and environmental protection facilities (ventilation, fume exhausting and cleaning).
3.0.5 Protective pad should be inserted to av6oid direct contact between the pipe transport equipment and the pipe.
3.0.6 Energy-efficient production process and government-recommended water-efficient or energy-efficient equipment shall be used for the steel pipe coating plant.
