ERW welding process refers to the heat generated by the resistance of the current flowing through the connecting metal. Therefore, a large current is required to charge the entire surface of the steel plate or coil to the welding length. During ERW welding, the current flowing through the entire conductor is 50/60 Hz.
HFW welding process is different from the high frequency process, because high frequency electromagnetic welding is only part of the metal heated by the induction coil. Both alternating current and direct current produce high frequencies. In these cases, a constant current welding generator and a constant voltage high frequency welding generator are used.
ERW is the general term for electric resistance welded steel pipe. It can be divided into two types: alternating current welding (AC) and direct current welding (DC). According to the different frequency, AC welding can be divided into low frequency welding, intermediate frequency welding, ultra high frequency welding and high frequency welding. High frequency welding (HFW) is mainly used for ordinary or thin-walled steel pipes. It includes contact welding and induction welding. DC welding is usually used for small diameter steel pipes. Generally, HFW is one of ERW production methods, which uses high-frequency welding technology. Therefore, ERW steel pipe includes HFW steel pipe.
Tips: ASTM A53 covers seamless and welded steel pipe with nominal wall thickness. The surface condition is usually black and hot-dipped galvanized. ASTM A 53 is produced mainly for pressure and mechanical applications, and is also used for transport of steam, water, gas line pipes.
ASTM A53 Grade B Seamless is our most polar product under this specification and A53 pipe is commonly dual certified to A106 B Seamless pipe.
ASTM A53 Grade B is the material under the American steel pipe standard, API 5L Gr.B is also the American standard material, A53 GR.B ERW refers to the electric resistance welded steel pipe of A53 GR.B; API 5L GR.B Welded refers to the material Welded steel pipe of API 5L GR.B.