In a piping system, an elbow is a pipe that changes the direction of the pipe. According to the angle, there are three kinds of Zui commonly used in 45° and 90°180°, and other irregular angle elbows such as 60° are also included according to engineering needs. The materials of the elbow are cast iron, stainless steel, alloy steel, calcinable cast iron, carbon steel, non-ferrous metals and plastics. The way to connect with the pipe is: direct welding (the usual way of Zui) flange connection, hot melt connection, electrofusion connection, screw connection and socket connection. According to the production process, it can be divided into: welding elbow, stamping elbow, hot bending elbow, push elbow, casting elbow, forged elbow, clip elbow, etc. Other names: 90° elbow, right angle bend, love and bend, white steel elbow, etc.
 
Stainless steel characteristics: strength, toughness index is good in all kinds of steel, its outstanding advantage is corrosion resistance, stainless steel must be used in chemical corrosive occasions, of course, the cost is also high.
 
There are many things to be aware of when using and maintaining stainless steel elbows. Users need to use them according to certain methods and use and maintain them in an accurate and fair manner. The notes are as follows:
 

1. Long-term storage of stainless steel elbows should be checked on schedule. The exposed surface should be kept clean, dirt removed, and stored neatly in a place where the air is dry and dry. It is strictly prohibited to be stacked or stored in the open air. The stainless steel elbow is often kept dry and ventilated, the retainer is clean and tidy, and stored in an accurate storage method.
    
2. When installing, the stainless steel elbow can be directly installed on the pipeline according to the connection mode, and installed according to the position used. Under normal circumstances, it can be installed at any position of the pipeline, but it is necessary to facilitate the inspection of the operation. Note that the flow direction of the stainless steel elbow medium should be upward from the longitudinal valve flap. The stainless steel elbow can only be installed horizontally. Stainless steel elbows should pay attention to the sealing during installation to prevent leakage and affect the normal operation of the pipeline.
    
3. When the ball valve, globe valve and gate valve of stainless steel elbow are used, they are only fully open or fully closed, and do not allow to adjust the flow to avoid erosion of the sealing surface and accelerate wear. The gate valve and the upper thread stop valve have an inverted sealing device, and the hand wheel is screwed to the position of the zui to tighten, so as to prevent the medium from leaking from the packing.
    
   4, stainless steel elbow application hand wheel, do not use levers or other tools to avoid damage to the valve. The handwheel rotates clockwise to close, and vice versa. Be fair when using it to ensure accurate use and methods.
    
4. The bolts of the stainless steel elbow valve packing gland should be tightened evenly and should not be pressed into a smashing state to avoid the movement of the valve stem or the leakage.
    
5. The stainless steel elbow should be kept clean during use. The transmission thread must be lubricated on schedule. When the fault is found, it should be used immediately to find out the cause and clear the fault.