1. Material selection standards
The anti-corrosion standards for FBE anti-corrosion spiral steel pipes require strict selection of materials to ensure that the materials meet relevant national standards and industry standards. In terms of plastic-coated composite steel pipes, there are also corresponding standards for the base material selected according to the caliber pressure. For example, seamless steel pipes are used as the base material for pressures exceeding 1.6Mpa, straight seam welded pipes are conventionally used as the base material for plastic-coated steel pipes below 1.6Mpa and below DN200, and spiral steel pipes are conventionally used as the base material for calibers above DN200.
2. Coating technical standards
FBE epoxy powder anti-corrosion complies with SY/T "Technical Standards for External Coating of Steel Pipelines with Fusion Bonded Epoxy Powder"; 2PE/3PE anti-corrosion complies with SY/T "Technical Standards for External Coating of Polyethylene for Buried Steel Pipelines".
3. Surface rust removal standards
Sandblasting and rust removal on the outer surface of steel pipes meets the requirements of GB/T to reach Sa2 1/2 level, and the anchor pattern depth on the surface of steel pipes is 40 - 100μm.
4. Coating thickness standard
The thickness of the anti-corrosion coating must exceed its critical thickness to play a protective role, which is generally 300μm to 400μm.
5. Coating construction process
Epoxy powder has always been applied by electrostatic spraying. The coating process of the double-layer fused epoxy powder coating is fine-tuned on the basis of the original single-layer fused epoxy powder spraying equipment. The spray guns are divided into three groups. The first group sprays the bottom layer powder, the second group sprays the outer layer powder, and the third group sprays the recycled powder. The sprayed powder can be recycled separately or together.
6. Quality inspection standards
There are corresponding standards for the quality inspection of FBE anti-corrosion spiral steel pipes, and the quality of the products is strictly controlled. However, the specific inspection indicators and methods are not mentioned in detail in the search results. However, in actual production and application, the adhesion, wear resistance, chemical corrosion resistance and other properties of the anti-corrosion layer will be tested according to relevant industry specifications.
