Connection and Corrosion-prevention Methods for Plastic-coated Steel Tube Line

It is emphasized that the connection and connection corrosion-prevention of plastic-coated steel pipe line is just the bottleneck impeding spreading application thereof. Several methods currently used at home and abroad for connection and connection corrosion-prevention of plastic-coated steel pipe line are described. Among the said methods there are the technique of inner joint-repair with the special machine which is too complicated and applicable for long-distance pipe line only and the technique of inner joint-repair with memory alloy material which is used with a very narrow scope due to high operational costs. The other methods include techniques for outer joint-repair like wrapping with anti-corrosion plastic tape or shrinking tape and flame spray and techniques for inner joint-repair like thread connection, groove connection, flange connection, slide-in connection and welding of internally-lining short-pipe, which are all rather applicable and enable reliable quality of joint repair and coating provided the engineering quality is well controlled and the relevant operation procedures closely followed.