Emergency help: grinding of regulating valves

Take a look at the following, it mentions the grinding of the regulating valve http://bbs.hcbbs.com/viewthread.php?tid=340896

Let me tell you, there are scars on the valve seat. If you have the conditions, make a tool to remove the valve seat, machine the valve seat once, process away the scarred area, and then install and grind it. During grinding, install the guide sleeve or the upper valve cover to ensure For concentricity grinding, use 400~800 grit grinding sand. If it is inconvenient to process, first use 100~200 grit grinding grit to grind away the scars on the valve seat, and then use 400~800 grit grinding grit to grind my QQ: 346660472

I just checked some content on the Internet, about grinding: How to perform valve grinding Valve grinding includes cleaning and inspection process, grinding process and inspection process. 1. Cleaning and inspection process: Clean the sealing surface in the oil pan, use professional cleaning agent, and check the damage of the sealing surface while washing. Fine cracks that are difficult to detect with the naked eye can be detected by coloring. After cleaning, the sealing surface of the valve disc or gate valve and the valve seat should be checked. Use a red pencil when checking. Use red lead to test redness, check the sealing surface impression, and determine the tightness of the sealing surface. ； Or use a pencil to draw several concentric circles on the sealing surface of the valve disc and valve seat, then rotate the valve disc and valve seat tightly, check the eraser of the pencil circles, and determine the tightness of the sealing surface. If the sealing is not good, a standard flat plate can be used to inspect the valve disc or gate sealing surface and the valve body sealing surface respectively to determine the grinding position. 2. Grinding process The grinding process is essentially a cutting process without a lathe. The depth of pits or small holes on the valve head or valve seat is generally within 0.5mm, and can be repaired by grinding. The grinding process is divided into coarse grinding, medium grinding and fine grinding. Rough grinding is to eliminate scratches, indentations, corrosion spots and other defects on the sealing surface, so that the sealing surface can obtain a higher flatness and a certain smoothness, which lays the foundation for medium grinding of the sealing surface. Rough grinding uses a grinding head or grinding seat tool, and uses coarse-grained sandpaper or coarse-grained abrasive paste. The particle size is 80#-280#. The particle size is coarse, the cutting volume is large, and the efficiency is high. However, the cutting lines are deep and the sealing surface surface is rough. Therefore, rough grinding only requires smooth removal of pits on the valve head or valve seat. Medium grinding is to eliminate rough lines on the sealing surface and further improve the flatness and smoothness of the sealing surface. Use fine-grained sandpaper or fine-grained abrasive paste with a particle size of 280#-W5. The particle size is fine and the cutting amount is small, which is beneficial to reducing roughness. ； At the same time, the corresponding grinding tools should be replaced and the grinding tools should be clean. After intermediate grinding, the contact surface of the valve should be bright. If you use a pencil to draw a few lines on the valve head or valve seat, gently turn the valve head or valve seat toward each other to erase the pencil lines. Fine grinding is the last process of valve grinding, mainly to improve the smoothness of the sealing surface. When finely grinding, W5 or finer parts can be diluted with engine oil, kerosene, etc., and then the valve head is used to grind the valve seat against the valve seat without using a grinding tool, which is more conducive to the tightness of the sealing surface. When grinding, generally turn it about 60-100° clockwise, then turn it about 40-90° in the opposite direction, grind it gently for a while, and check it once. When it is polished until it shines brightly, and a circle of very thin lines can be seen on the valve head and valve seat. When the color reaches black and bright, gently grind it several times with engine oil, and then wipe it clean with clean gauze. After grinding, other defects should be eliminated, that is, the valve head should be assembled as soon as possible to avoid damaging the ground valve head. Whether the manual grinding is coarse or fine, it is always lifted and put down. ； Rotate, reciprocate ； The grinding process combines tapping, reversing and other operations. The purpose is to avoid the repetition of abrasive particle trajectories, so that the grinding tool and sealing surface can be ground evenly, and the flatness and smoothness of the sealing surface can be improved. 3. Inspection stage The inspection stage always runs through the grinding process. Its purpose is to grasp the grinding situation at any time and be aware of it, so that the grinding quality can meet the technical requirements. It should be noted that when grinding different valves, grinding tools adapted to various sealing surface forms should be used to improve grinding efficiency and ensure grinding quality. Valve grinding is a very delicate job that requires continuous experience, exploration, and improvement in practice. Sometimes the grinding is very good, but it still leaks steam and water after installation. This is because there is an imagination of grinding deviation during the grinding process, the grinding rod in hand is not vertical or skewed, or the size and angle of the grinding tool are deviated.

We specialize in the repair of regulating valves. Grinding is rarely used. Generally, cutting can be used to meet the sealing requirements. Pressures of hundreds of kilograms are no problem.