Restricted by production industry,the market competition of seamless steel pipe is just like a fierce battlefield.Many enterprises engage in price war as cost of seamless steel pipe is too high.As a consequence,the economic benefit of enterprises are declining gradually.At present a substitute for seamless steel pipe called straight seam steel pipe appears in market.Letís see the differences between them as follows.
1.The quality of welding seam directly determines the quality of welding pipe,which is the biggest difference between welding pipe and seamless pipe.After being welded with high frequency,the coke in straight seam canít be eliminated.The welding seam and matrix are just joined together without fully smelting together.It canít stand the test of time and high pressure.Steel pipe with thermotension and reducing tube have to be wholly heated by 800 degrees heat and annealed after being welded with high frequency.Through this series of process,the welding seam and matrix are smelted together with same organization and capability.This is a great transition from seam to seamless.
2.Different processes make different qualities of product.After being welded with high-frequency,the steel pipe with themotension and reducing tube is dealt by another process which is not included in the process of straight seam welding pipe,that is,removing the sentusi inside and outside.The sentusi will influence the flow of fluid in pipes.They will block the normal flow of fluid,thus generating swirl.According to the principle of fluid mechanics,the pressure for part of welding seam will be certainly increased.Uneven stress will make the safety factor of welding pipe decline greatly.The danger of sentusi is taken into fully consideration in the process of steel pipe with thermotension and reducing tube.The sentusi are eliminated which will make its wall thickness even and its shape same with seamless pipe.From this point of view,steel pipe with thermotension and reducing tube is transited from seam to seamless.