Construction pipes are typically more light weight, and have thinner walls. Off-shore pipes have a better consistency and are typically straighter. Typically, these pipes are used in instances when the pipe is not put under a high degree of stress.
From the very beginning, the provided steel plate width in the project is considered by 2500㎜ and 2000mm, and the plate length is fixed size. For the dredging pipes ofφ1829*25㎜, its loading extending perimeter is fixed on L=5667±3㎜.The loading groove is conducted by the process guideline, the loading way take the semi-automatic flame cutting method, the two ends of the finished pipe product implement the magnetic automatic flame cutter chamfering or cutting.
After the steel plate is loading the finished product, it must conduct the length and width inspection on each net material, its diagonal deviation ≤5㎜. Pre-bending joint production work section of dredging pipes. The qualified net material conduct the end pre-bending before rolling, the pre-bending length of the two ends is 350㎜. It takes 1000 tons plate type of pressing machine to pre-bend. The two ends after pre-bending are inspected by the inside arc sample plate. After the qualified inspection, foundation pipes can implement the next rolling working procedure.
Take 35*3000 three spindles rolling machine to roll the shell ring. In the form of the shell ring, the foundation pipe must conduct the production by four to six descending stroke method. Single shell ring vertical welding seam inside and outside nozzle welding: It implements by the welding process appraisal plan after the qualified inspection. Single shell ring put together to be branch
1. Assembly and put together to the needed size by the design length.
2. Joint clearance ≤2㎜, butt joint cross nozzle ≤2㎜
Inside and outside ring welding seam welding. Dredging pipe will be implemented by the welding process appraisal plan after the qualified inspection. Finished pipes length fixed size: It takes the magnetic automatic flame cutter to carry on the chamfering or cutting on the two ends of the finished pipe product, and ensures the length of the finished pipe product after cutting reaches the scope of ±10㎜.The ex-factory inspection of the finished pipe product: After the off-shore pipe becomes the finished product, it shall conduct the 100% ultrasonic inspection on all the welding seams, the inspection standard shall carry on by CSA W59-03 standard.
It is estimated that the construction pipes will arrive in installment. The raw material will arrive at the company on about Nov 15. After acceptance to qualification, it shall start to produce them. These pipes are estimated to be ended on about November 25, 2009.