This is a steel casing project. Steel pipe specification is φ1829*25.The total tubular piles length is 549 meters, and the total weight is 610 tons. Pipe factory organizes the production according to ASTM A252 standard. The two ends type (clutch) of the finished casing pipes meet the user demand.
The steel plate material used in the steel pipe manufacturing shall be C350. It is attached the qualified Quality Inspection Certificate on delivery of the steel plate. The steel plate shall be re-checked by the current standard after in-factory. The welding wire used in the off-shore pipes welding is H08MnA, the welding flux takes SJ301, and they shall attach the Production Permit of The Factory and Product Qualification Certificate.
The deviation of two ends of the tubular pile and the middle outer diameter perimeter is ±12mm.The deviation of the steel pipe ellipse degree ≤±5mm.Pipe ends plane slope deviation ≤±2㎜.The neighboring shell ring interface edge height difference (cross groove) ≤±2㎜. The casing pipe length deviation ±25.4㎜.The steel pipe bending degree (straight degree) deviation ≤0.2%L.The two ends slope groove of the steel pipe 30-35 degrees. Each section steel pipe only permits to produce one vertical welding seam. The bending direction of the off-shore pipe for manufacturing the shell ring shall be consistent with the pressing and extension direction of the steel plate.
The production in the steel pipe factory take the process of inside and outside double side submerged arc and carbon arc air gouging. All the welding seams are taken by 100% ultrasonic inspection, the ultrasonic inspection standard shall be accepted according to CSA W59-03 standard. The welding seam grip edge depth shall be not more than 0.5㎜. The strength height of the butt joint welding seam is 0～3.5㎜.
The steel pipe shape geometry size deviation shall be inspected according to AS1163. The welding seam quality grade shall be accepted by API5L standard. The tubular piles shall conduct the code on the whole batch of the steel pipe by the specification, then it shall carry on code and spraying of the sign in the factory. After the steel pipe finished product carry out the acceptance in qualification, it shall conduct the leveling treatment on the site when they are piled. It shall use the wood chock to plug on the two ends to prevent the gliding movement after the steel pipes are piled. After the production in the welded pipes factory, it shall conduct the lift operation by the professional people holding certificate on duty in the outside piling and ex-factory vehicle transportation. Then it can prevent the distortion due to the bounce by two ends of the pipe section and pipe body.