輸油、氣鋼管防腐用熱縮套管的要求：鋼管補口施工總要求補口前，必須對補口部位進行清理, 將環向焊縫及其附近的毛刺、焊渣、汙物、油及其雜物清理乾淨。對補口部位表面進行除鏽處理。表面除鏽處理品質應達到《塗裝前鋼材表面銹蝕等級和除鏽等級》GB/T8923規定的Sa2.5一Sa3.0級。可選用噴沙或電動工具除鏽。補口搭接部位的聚乙烯層應打磨至表面粗糙。其端部進行坡口處理, 坡角不大於30然後用火焰加熱器對補口部位進行預熱。防腐熱縮套與聚乙烯防腐層搭接寬度應不小於100mm。如果濕度大於85% 或下雨、雪天應停止施工。
輸油、氣鋼管防腐用熱縮套管施工後的品質檢驗：防腐熱縮套或纏繞帶的品質檢驗：補口外觀應逐個檢查防腐熱縮套或纏繞帶表面應光滑平整、無皺折、無氣泡, 兩端坡角處與熱縮套(帶) 貼合緊密無空隙.表面沒有碳化現象。熱縮套管邊緣應有熱熔膠粘劑均勻溢出。補口處應用火花檢漏儀逐個進行針孔檢查。防腐熱縮套的粘接力應符合要求。
Introduction of heat shrinkable sleeve for oil and gas steel pipe anticorrosion
Steel pipe anti-corrosion heat shrinkable sleeve is a new type of steel pipe weld anti-corrosion material with good performance and easy operation. It is composed of two layers of material and hot melt adhesive layer. The substrate is a plastic sleeve formed by extrusion, radiation crosslinking and stretching of a polyethylene raw material. Hot melt adhesive is a kind of special adhesive. It is solid at normal temperature. It can be flowed in a molten state and can be coated on a substrate. It has good adhesion to metal and plastic.
Requirements for heat-shrinkable sleeves for oil and gas steel pipe anti-corrosion: Before the total requirements for steel pipe joint construction, the joints must be cleaned, and the circumferential welds and their nearby burrs, welding slag, dirt, oil And its debris is cleaned up. Derusting the surface of the mouth part. The surface derusting treatment quality should reach the Sa2.5-Sa3.0 grade specified in GB/T8923, “Corrosion grade and derusting grade of steel surface before painting”. It can be rusted by sandblasting or electric tools. The polyethylene layer of the lap joint should be ground to a rough surface. The end is subjected to bevel treatment, the slope angle is not more than 30, and then the mouth portion is preheated by a flame heater. The width of the anti-corrosion heat shrinkable sleeve and the polyethylene anti-corrosion layer shall not be less than 100mm. If the humidity is greater than 85% or it is raining or snowy, stop construction.
Quality inspection after construction of heat-shrinkable casing for oil and gas steel pipe anti-corrosion: quality inspection of anti-corrosion heat shrinkable sleeve or winding belt: the appearance of the joint should be checked one by one, the surface of the anti-corrosion heat shrink sleeve or the winding belt should be smooth and flat, no wrinkles, No air bubbles, the edge of the two ends and the heat shrink sleeve (belt) fit tightly and without voids. The surface has no carbonization. The edge of the heat shrinkable sleeve should have a uniform overflow of the hot melt adhesive. A pinhole inspection is performed one by one using a spark leak detector at the mouth. The adhesion of the anti-corrosion heat shrink sleeve should meet the requirements.