Steel pvc fitting pipes include ordinary steel pipes, galvanized steel pipes and seamless steel pipes. Ordinary steel pipes are used for non-domestic drinking water pipes or general industrial water supply pipes. Galvanized steel pipe surface produced by hot-dip galvanizing process is to prevent rust and corrosion, so as not to affect water quality. It is suitable for drinking water pipes or some industrial water pipes with high water quality requirements; seamless steel pipes are used for high-pressure pipe networks , Its working pressure is above 1.6MPa. The connection methods of steel pipes include threaded connection, welding and flange connection. Threaded connection is to use threaded pipe fittings to connect. Most of the accessories are made of malleable cast iron, divided into galvanized and non-galvanized, and their corrosion resistance and mechanical strength are relatively large. There are few steel parts at present. Galvanized steel pipes must be connected by threads, and their fittings should also be galvanized fittings. This method is mostly used for surface installation of pipelines.
Welding is to connect two sections of pipelines together with welding machine and welding rod. The advantages are tight joints, no water leakage, no accessories, and rapid construction. But it cannot be disassembled. Welding is only suitable for non-galvanized steel pipes. This method is mostly used for concealed pipelines. The flange is connected to a pipe with a larger pipe diameter , and the flange is often welded (or threaded) on the pipe end, and then the two flanges are connected together with bolts, and the two pipes are also Connected together. Flange connections are generally used to connect valves, check valves, water meters, water pumps, etc., as well as pipe sections that need to be frequently disassembled and overhauled. The most commonly used water supply plastic pipes are water supply unplasticized polyvinyl chloride pipes (UPVC) and water supply polypropylene pipes . In addition, there are polyethylene pipes, which are suitable for conveying water with a temperature not exceeding 40°C. The relevant standards follow the requirements of "Polyethylene (PE) Pipes for Water Supply" GB/T13663; cross-linked polyethylene.
Polybutene (PB) tube, suitable for conveying water at a temperature of 20"-90℃. They all have strong chemical stability, corrosion resistance, and are not subject to acid, alkali, salt, oil and other media Corrosion, smooth pipe wall, good hydraulic performance, light weight, easy processing and installation. But the common shortcomings are poor temperature resistance and low strength. Therefore, the use is also subject to certain restrictions. Water-hardened polyvinyl chloride pipe (UPVc) ), the temperature of the conveying water does not exceed 45℃. UPVC pipes generally adopt socket connection, and socket bonding is suitable for pipe outer diameter 20～1601m; rubber ring connection is suitable for pipe outer diameter greater than or equal to 63mm; with metal pipe fittings The connection of valves, valves, etc. adopts threaded or flanged connection. Water supply polypropylene pipe (PP pipe) is suitable for system working pressure not greater than 0.6Mpa and operating temperature not greater than 70℃. Water supply polypropylene pipe adopts hot melt socket connection.
When connecting with metal pipe fittings, use polypropylene pipe fittings with metal inserts as a transition. The pipe fittings and polypropylene pipes are connected by hot-melt sockets, and the metal pipe fittings are connected by threads. In fact, it is a kind of plastic pipe with general joints. Adhesive. Because of its poor frost resistance and heat resistance, it is difficult to use as a hot water pipe. The pipe is easy to break and deform when exposed to heat. In most cases, PVC pipes are suitable for electrical threading pipes and drainage pipes. The copper pipes and their fittings have complete varieties and specifications, with a large diameter range, which can be selected arbitrarily from 6mm to 273mm. Copper pipes are easy to bend, process, and change shapes, which can meet all the needs of pipeline wiring and interconnection in engineering installation. During the on-site construction, the temporary cutting, bending and polishing of copper pipes are easy and free. Various pipes and fittings can be assembled and transported to the site, or they can be temporarily installed on site with satisfactory results. Copper is a hard texture. Metal, and corrosive. It can be used in different environments without being damaged. From the history of foreign use, the use time of many copper pipes has exceeded the service life of the building itself. Therefore, copper water pipes are absolutely safe and reliable Water pipes.
