1. You should first determine what material is flowing through the pipeline. If the pressure of the general water plant pipeline is low, it is more affordable to choose a straight seam elbow. The straight seam elbow is made of straight seam steel pipe. If it is high temperature, you must choose a seamless elbow with good pressure resistance. If the pipeline is used in chemical or corrosive equipment, you must choose stainless steel or alloy materials.
2. Large-diameter thick-walled elbows have a large pressure resistance. You should choose flaw detection welding and then take x-rays to detect whether there are pores.
3. Look at the price. Many small workshops use second-hand scrap steel pipes to push elbows. The material cannot guarantee the service life and is also short.
4. How to buy high-quality and relatively affordable products? You can choose a short radius elbow while ensuring the material and wall thickness. Usually, a 1.5d long radius elbow is selected. The short radius is generally 1d elbow. The pressure material wall thickness can ensure that there will be no problems with the pipeline, but the cost is very different.
