Comparison test on the primer property of heat shrinkable tape as field coating for welded joint

The installation quality of field coating for welded joint with heat shrinkable tape depends to a great extent on the quality of coating material except the impact of installation way, which is directly related to the integral safety for the corrosion control of pipeline. Taking into account of the relevant regulations on testing parameters and criteria specified currently in the standards for joint coating materials of heat shrinkable tapes, a test comparison program of joint coating materials as heat shrinkable tapes has been formulated and perfected. Totally, eight types of heat shrinkable tape materials collected from the major manufactures in China and abroad have been code numbered according to the consistent rules, and compared and analyzed in terms of primer thickness, shear strength, solid content and water absorption of primer, cathodic disbonding and adhesion strength, and therefore, a suggestion for amendment of the relevant criteria in the existing standards has been proposed.