ERW steel pipes are steel pipes whose welds are parallel to the longitudinal direction of the steel pipe. They are mainly used in water supply engineering, petrochemical industry, chemical industry, power industry, agricultural irrigation, and urban construction. Its application scale is wide, the production process is simple, the production efficiency is high, the cost is low, and the growth is rapid. So what do we need to pay attention to when purchasing ERW steel pipes?
1) Divided by type: straight seam steel pipe, seamless steel pipe, spiral steel pipe, etc.
2) Classification of ERW steel pipe shape of straight seam steel pipe: square pipe, rectangular pipe, oval tube, flat oval tube, semicircular tube, etc
Ordinary straight seam pipes are implemented in GB/T3091-2015. If they are used as structures (columns and other types of applications), they can be competent. However, if it is used for processing (building roller bodies), pressure equipment (applied to boiler equipment, oil and gas pipelines), the requirements for the ovality, straightness and weld of the straight seam steel pipe are a bit low.
The requirements for processing ERW pipes are much higher than those for structural ERW pipes. ERW steel pipes for fluid transportation can be divided into ERW steel pipes for ordinary fluid transportation and ERW pipes for pressure (in fact, there are many types of fluid pipes, and they are only classified according to whether they are pressure-bearing)
A. The test standards of steel pipes for low-pressure fluid transportation can be implemented in accordance with GB/T3091-2015.
B. The production of pressure-bearing ERW pipes is subject to standards such as GB/T3087 or API or GB/T9711.2. These standards have high requirements.