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Installation guidelines for valves and practical connection methods: low-temperature welding and silver brazing. Be sure to keep in mind the intended use of the valves recommended, as well as analyze the environment in which they will be used, in order to determine which type of valve is most suitable for installation. Before installing the correct valve, to prevent damage to it and ensure its optimal performance, please read the installation guide. 1. First, cut the pipe vertically, trim and remove burrs, then measure the pipe diameter. 2. Use gauze or a wire brush to clean the pipes and cutting areas until their metal surfaces are shiny. It is recommended not to use steel wool. 3. Apply flux on the outside of the pipe and inside the welding shield; the flux must completely cover the welding surface. Please use flux in moderation. 4. Ensure that the valve is in the open position. Heat the pipe first. Transfer as much heat as possible from the pipe to the valve. Avoid prolonging the heating time of the valve itself. 4a. Method of silver brazing: Assemble the components that are to be brazed together. If the parts coated with flux are allowed to stand upright, the moisture in the flux will evaporate, and the dried flux can easily fall off, causing the exposed metal surface to oxidize easily. During connection assembly, insert the pipe into the sleeve until it meets resistance. Assembly is required to ensure solid support, so that the entire brazing process can remain in a straight position. Note: For valves with a nominal diameter of 1 inch or larger, it is difficult to heat the connecting components to the required temperature all at once. To maintain a normal temperature over a large area, two welding torches are usually required. It is recommended to perform appropriate preheating of the entire sleeve area. It is recommended to use an acetylene flame to heat the connecting components. First, heat the pipe starting from 1 inch away from the valve, then use a flame to bake the pipe in short intervals, moving up and down around it, while rotating the pipe at an appropriate angle to prevent it from being burned through. The flame must move continuously and is not allowed to stay at one point. The sleeve base of the valve is baked using a flame. The heating must be even; the process of using a flame to bake the valves and pipes should continue until no sound is emitted from the flux on the valves. Do not overheat the valve. When the flux becomes liquid and takes on a translucent appearance on the pipes and valves, the flame is moved back and forth along the axis of the connecting components in order to maintain heat in those components, especially in the area where the valve sleeve sits. 5. Use an appropriate amount of solder: If wire solder is used, then for valves with a nominal diameter of 3/4 inch, 3/4 inch solder should be used, and so on. If too much solder is used, some of it may flow past the obstruction in the pipe and clog the sealing area. When installing the connecting components, it can be seen that the solder and brazing alloy continue to flow. 5a. Silver brazing method: Apply the solder wire or rod to the pipe sleeve in the valve. When the welding rod or wire enters the joint, move the flame away from it. When the alloy flows into the joint, move the flame back and forth. Once the appropriate temperature is reached, the alloy will flow rapidly and easily into the space between the pipe casing and the valve sleeve. Once the joint is filled, the edge of the welded alloy can be seen. 6. When the solder is in a viscous state, use a brush to remove any excess solder. After the solder cools, a strip is wrapped around the port of the valve. Silver brazing: If different brazing materials are used, the strength of the brazed joint is not necessarily high; the strength depends on proper and thorough cleaning and maintenance between the pipe casing and the valve sleeve. The mechanical tolerances of the internal diameter and the surface smoothness requirements for the valve sleeves made by silver brazing are very precise, in order to ensure sufficient adhesion. Note: During the cleaning and removal process, careful attention should be paid to any residues of the cleaning agent. Soldering on surfaces that are already dirty or not properly cleaned yields unsatisfactory results, as silver solder alloys do not flow over or adhere to oxides, while oily surfaces as well as exposed areas prone to oxidation lead to the formation of voids and impurities that prevent the flux from functioning properly. Threaded connection The accumulation of hard residues, dirt, or any foreign substances inside the pipes can impair the efficiency of the valve and cause serious damage to its key components. The interior of the pipeline must be thoroughly cleaned with air or steam. When threading a pipe, it is necessary to determine the size and length of the pipe threads to prevent the pipe from filling the valve seat and valve disc. Thoroughly clean the end of the thread to remove any harmful steel or iron deposits. To achieve a stronger weld, Teflon tape or pipe adhesive should be used. Only a small amount of pipe adhesive can be used on pipe threads, but it must never be used on valve threads. Do not allow any pipe adhesive to enter the valve body to avoid damaging the valve disc and seat. Before installation, cut off the fluid flowing through the valve to ensure it functions properly. The valve must be completely closed before installation. Put the wrench on the hex bolt head near the pipe to prevent any possible deformation. After installing the valve, it is necessary to support the pipeline: hanging pipes can cause the valve to deform and fail. Flange connection To ensure proper installation of the valve flange connection, the following steps need to be followed. First, clean the connection areas carefully, then loosely install two or three bolts at the base portion. Next, carefully insert the gasket into the joint. The bottom bolts help to position the gasket and keep it in the proper place. Then, the bolts should be tightened in a crosswise manner, rather than in a circular pattern; this helps to avoid excessive concentration of pressure). After normal use for a period of time, check to ensure that all bolts are tightened and tighten them again if necessary.