Wenzhou Unique Valve Co., Ltd.
Different Connection Ends for Valves
May 06, 2021
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Different connection ends of valves are as follows:
1. Valves with flange connections: The valve body has a flange and is connected to the pipeline by a flange.
2. Valves with threaded ends: The valve body has internal or external threads, and the valve is connected with the pipeline by threads.
3. Valves with welding ends: The valve body has a welding junction and is connected to the pipeline by welding.
4. Valves with clamping ends: The valve is connected with the pipeline by clamping.
5. Valves with cutting ferrules: A valve that uses ferrule to connect the pipeline.
Welding and silver brazing
1. First cut the pipe in the vertical direction, trim and remove burrs, and measure the pipe's diameter.
2. Use gauze or steel wire brush to clean the pipe to make the metal surface shiny. It is recommended that steel wool should not be used.
3. Apply flux to the outside of the pipe and inside of the welding cover. The flux must completely cover the welding surface. Please use flux sparingly.
4. Make sure that the valve is open. Heat the pipe first. Transfer heat as much as possible from the pipe to the valve. Avoid extending the heating time of the valve itself.
5. Silver brazing methods: Assemble the parts that need to be brazed. If the parts that are allowed to be coated with flux are in an upright position, the moisture in the flux will evaporate, and the dry flux will easily fall, causing the exposed metal surface to be easily oxidized. When assembling, insert the pipe into the pipe sleeve until it encounters an obstruction. The assembly is to ensure that there is stable support, so that the entire brazing operation can be maintained in a straight position. Please note that it is difficult to heat the connecting parts to the required temperature at one time for valves with a nominal diameter of one inch or greater. In order to maintain a normal temperature over the entire large area, two welding torches are usually required. It is recommended that the entire sleeve area should be properly preheated. It is recommended to use acetylene flame to heat the connecting parts. Start heating the pipe at the position being 1 inch away from the valve, and then flame bake the pipe alternately up and down at a short distance from the pipe, and rotate the pipe at an appropriate angle to avoid burning the pipe. The flame needs to be moved continuously and it is not allowed to stay at a certain point. Bake the sleeve base of the valve with flame. The heating should be uniform, and the process of baking the valve and pipeline with flame should continue until there is no sound coming from the flux on the valve. Do not overheat the valve. When the flux becomes liquid and appears translucent on the pipes and valves, start to bake along the axis of the connecting parts forward and backward by the flame to keep the connecting parts, especially the base part of the valve sleeve hot.
6. Use proper amount of solder: If you use wire solder, then use 3/4 inch solder for valves with a nominal diameter of 3/4 inch. If too much solder is used, some solder may flow through the blocking part of the pipe and block the sealing area. When installing the connecting parts, you can see the solder and brazing alloy continue to flow.
7. Silver brazing: When the welding rod or wire enters the connecting part, the flame should be removed from it. When the alloy flows into the connecting part, move the flame back and forth. After reaching the proper temperature, the alloy will quickly and easily flow into space between the pipe shell and the valve sleeve. After the connecting part is filled, the edges of the welding alloy will be seen.
8. When the solder is in a sticky state, use a brush to remove the excess solder. After the solder is cooled. If different brazing materials are adopted for silver brazing, the strength of the brazing connection is not necessarily very good. The strength depends on the normal, large-scale cleaning and maintenance between the pipe shell and the valve sleeve. The mechanical tolerances and surface smoothness of the internal diameter of the silver brazed valve sleeve are required to be very precise to ensure sufficient adhesion. Please note that in the cleaning and removal processes, the residue of the cleaning medium should be carefully observed. Brazing on a dirty or improperly cleaned surface is difficult to achieve good welding because the silver brazing alloy does not flow or adhere to the oxide.
Flange ends
In order to ensure proper installation of flange connection, the following steps need to be followed: First, carefully clean the connecting parts, and then loosely install two or three bolts on the base. Carefully insert the gasket into the connection. The bottom bolt helps to locate the gasket and maintain the proper position. Then insert the bolts in a crossing and tightening way; do not use an encircling and tightening way, which helps to eliminate too concentrated pressure. After a period of normal use, check that all bolts are tightened, and re-tighten if necessary.
Threaded ends
The accumulation of hard slags, dirt, or any foreign matter in the pipeline may hinder the working efficiency of the valve and seriously damage the key components of the valve. The inside of the pipe must be thoroughly cleaned with air or steam. When tapping the pipe, measure the size and length of the pipe thread to avoid filling the valve seat and disc. Thoroughly clean the thread ends to remove any harmful steel or iron deposits. If you want to weld more firmly, use Teflon tape or pipe adhesive. Only a small amount of pipe adhesive can be used on pipe threads, but it should never be used on valve threads. Do not allow any pipe adhesive to flow into the valve body to avoid damage to the valve disc and valve seat.
Before installation, cut off the fluid passing through the valve to make the valve work normally. Close the valve completely before installation. Put the wrench on the head of the hexagonal bolt near the pipe to avoid possible deformation. After installing the valve, support the pipeline, because a drooping pipeline will deform the valve and cause it to fail.
1. Valves with flange connections: The valve body has a flange and is connected to the pipeline by a flange.
2. Valves with threaded ends: The valve body has internal or external threads, and the valve is connected with the pipeline by threads.
3. Valves with welding ends: The valve body has a welding junction and is connected to the pipeline by welding.
4. Valves with clamping ends: The valve is connected with the pipeline by clamping.
5. Valves with cutting ferrules: A valve that uses ferrule to connect the pipeline.
Welding and silver brazing
1. First cut the pipe in the vertical direction, trim and remove burrs, and measure the pipe's diameter.
2. Use gauze or steel wire brush to clean the pipe to make the metal surface shiny. It is recommended that steel wool should not be used.
3. Apply flux to the outside of the pipe and inside of the welding cover. The flux must completely cover the welding surface. Please use flux sparingly.
4. Make sure that the valve is open. Heat the pipe first. Transfer heat as much as possible from the pipe to the valve. Avoid extending the heating time of the valve itself.
5. Silver brazing methods: Assemble the parts that need to be brazed. If the parts that are allowed to be coated with flux are in an upright position, the moisture in the flux will evaporate, and the dry flux will easily fall, causing the exposed metal surface to be easily oxidized. When assembling, insert the pipe into the pipe sleeve until it encounters an obstruction. The assembly is to ensure that there is stable support, so that the entire brazing operation can be maintained in a straight position. Please note that it is difficult to heat the connecting parts to the required temperature at one time for valves with a nominal diameter of one inch or greater. In order to maintain a normal temperature over the entire large area, two welding torches are usually required. It is recommended that the entire sleeve area should be properly preheated. It is recommended to use acetylene flame to heat the connecting parts. Start heating the pipe at the position being 1 inch away from the valve, and then flame bake the pipe alternately up and down at a short distance from the pipe, and rotate the pipe at an appropriate angle to avoid burning the pipe. The flame needs to be moved continuously and it is not allowed to stay at a certain point. Bake the sleeve base of the valve with flame. The heating should be uniform, and the process of baking the valve and pipeline with flame should continue until there is no sound coming from the flux on the valve. Do not overheat the valve. When the flux becomes liquid and appears translucent on the pipes and valves, start to bake along the axis of the connecting parts forward and backward by the flame to keep the connecting parts, especially the base part of the valve sleeve hot.
6. Use proper amount of solder: If you use wire solder, then use 3/4 inch solder for valves with a nominal diameter of 3/4 inch. If too much solder is used, some solder may flow through the blocking part of the pipe and block the sealing area. When installing the connecting parts, you can see the solder and brazing alloy continue to flow.
7. Silver brazing: When the welding rod or wire enters the connecting part, the flame should be removed from it. When the alloy flows into the connecting part, move the flame back and forth. After reaching the proper temperature, the alloy will quickly and easily flow into space between the pipe shell and the valve sleeve. After the connecting part is filled, the edges of the welding alloy will be seen.
8. When the solder is in a sticky state, use a brush to remove the excess solder. After the solder is cooled. If different brazing materials are adopted for silver brazing, the strength of the brazing connection is not necessarily very good. The strength depends on the normal, large-scale cleaning and maintenance between the pipe shell and the valve sleeve. The mechanical tolerances and surface smoothness of the internal diameter of the silver brazed valve sleeve are required to be very precise to ensure sufficient adhesion. Please note that in the cleaning and removal processes, the residue of the cleaning medium should be carefully observed. Brazing on a dirty or improperly cleaned surface is difficult to achieve good welding because the silver brazing alloy does not flow or adhere to the oxide.
Flange endsIn order to ensure proper installation of flange connection, the following steps need to be followed: First, carefully clean the connecting parts, and then loosely install two or three bolts on the base. Carefully insert the gasket into the connection. The bottom bolt helps to locate the gasket and maintain the proper position. Then insert the bolts in a crossing and tightening way; do not use an encircling and tightening way, which helps to eliminate too concentrated pressure. After a period of normal use, check that all bolts are tightened, and re-tighten if necessary.
Threaded ends
The accumulation of hard slags, dirt, or any foreign matter in the pipeline may hinder the working efficiency of the valve and seriously damage the key components of the valve. The inside of the pipe must be thoroughly cleaned with air or steam. When tapping the pipe, measure the size and length of the pipe thread to avoid filling the valve seat and disc. Thoroughly clean the thread ends to remove any harmful steel or iron deposits. If you want to weld more firmly, use Teflon tape or pipe adhesive. Only a small amount of pipe adhesive can be used on pipe threads, but it should never be used on valve threads. Do not allow any pipe adhesive to flow into the valve body to avoid damage to the valve disc and valve seat.
Before installation, cut off the fluid passing through the valve to make the valve work normally. Close the valve completely before installation. Put the wrench on the head of the hexagonal bolt near the pipe to avoid possible deformation. After installing the valve, support the pipeline, because a drooping pipeline will deform the valve and cause it to fail.
