How to deal with stainless steel elbow

The main difference between stainless steel elbow and carbon steel elbow is that the material is different. The chemical composition of stainless steel will keep the surface of stainless steel elbow free from corrosion and rust for a long time. However, we also need to pay attention to the cleaning and installation.

 

Cleaning instructions for stainless steel elbow

 

1. According to the requirements and surface conditions of the workpiece, alkali cleaning, water-soluble cleaning agent, chlorine solvent sand blasting, shot blasting and other methods are used for cleaning;

 

2. Generally, pickling is not used to clean stainless steel elbows.

 

How to deal with stainless steel elbow

Correct cleaning of stainless steel elbow can improve its safety performance and prolong its service life. The welding rod should be kept dry when using. The titanium calcium type should be dried at 150 ℃ for 1 hour, and the low hydrogen type should be dried at 200-250 ℃ for 1 hour (repeated drying is not allowed, otherwise the coating is easy to crack and peel), so as to prevent the coating from sticking oil and other dirt, so as to increase the carbon content in the weld and affect the quality of the weldment. When the elbow is welded, carbides are precipitated by repeated heating, which reduces the corrosion resistance and mechanical properties. After welding, the hardenability is large and cracks are easy to occur. If the same type of welding rod is used, preheating above 300 ℃ and slow cooling treatment at 700 ℃ after welding must be carried out. If post weld heat treatment is not available, chromium nickel stainless steel electrode should be used.

 

Installation instructions of stainless steel elbow

 

1. Before installation, it is necessary to carefully check each standard and diameter of the stainless steel elbow to see if it meets the use requirements, eliminate the defects caused by the transportation process, and eliminate the dirt of the stainless steel elbow, and make preparations before installation.

 

2. During installation, stainless steel elbow can be directly installed on the pipeline according to the connection mode, and installed according to the use position. Generally, it can be installed at any position of the pipeline, but it needs easy operation and maintenance. It should be noted that the medium flow direction of the cut-off stainless steel elbow should be upward under the longitudinal valve disc, and the stainless steel elbow can only be installed horizontally. Pay attention to the sealing of stainless steel elbow during installation to prevent leakage and affect the normal operation of the pipeline.

 

3. The bolts of the packing gland of stainless steel elbow valve should be tightened evenly, and should not be pressed into a crooked state, so as to avoid bumping, hindering the movement of the valve stem or causing leakage.

 

4. The ball valve, globe valve and gate valve with stainless steel elbow are only used for full opening or full closing, and are not allowed to be used for regulating flow, so as to avoid erosion of sealing surface and accelerated wear. There is a reverse sealing device in the gate valve and the upper thread stop valve. The hand wheel is rotated to the top position and tightened to prevent the medium from leaking from the packing.