On drawings, threaded fittings are depicted in a standardized manner. The nominal dimension is listed first, followed by the description. When two or more ends of the fitting are not of the same dimension, the dimension of the run comes first, followed by the dimension of the branches, and so on. When reducing fittings are used, the largest dimension comes first, followed by the smallest. As an example, a 1 x 1 x 3/4 Street Tee; a 1 x 1 x 3/4 45° Y Bend; a 1 x 3/4 x 1/2 x 1/4 Cross; and so on are all examples of 1 x 1 x 3/4 shapes. The thread size on threaded fittings will be the same as the nominal pipe size thread as specified by the American National Standards Institute. Types of Threads The majority of pipe applications make use of threaded fittings, and their connections are typically distinguished by one of the following systems:American National Standard Pipe Threads (NPT) and British Standard Pipe Threads (BSPT) are two types of pipe threads.The angle of taper is the most significant distinction between these two. In the NPT system, thread taper angles are 60 degrees, whereas the British Standard Pipe Thread (BPST) system uses a taper angle that is slightly lower at 55 degrees. As an alternative to threaded pipe fittings with a tapered bore, these systems specify straight pipe thread fittings, which do not rely on a taper to provide a tight seal against pressure loss or leakage. In most cases, a suitable sealant is required in order to ensure that the seal integrity of the joint or connection is maintained. The majority of threaded pipe fittings are designed with right-handed (RH) threads, but there are a few left-handed (LH) thread options to choose from as well.The nominal outside diameter and thread pitch of metric pipe fittings are used to distinguish them from their imperial counterparts. For example, the outside diameter of an M12x1.5 metric pipe nipple would be 12 millimeters and the thread pitch would be 1.5 threads per millimeter, for a total of 12 millimeters.Screw fittings are typically threaded from the inside out. Except for the street fitting, which has one external thread and one internal thread in the case of a simple elbow, all fittings are threaded in the same direction. Pipes can be https://www.flangeschina.com/threaded-flanges" style="text-decoration: underline; color: rgb(255, 0, 0); threaded Flange in the field with relative ease. Using Teflon tape or pipe compound to join threaded pipes and fittings can make the job easier. When applying the compound, it is recommended that it be applied only to the external threads in order to avoid the introduction of any impurities into the pipeline during joint assembly and subsequent assembly.According to the complexity of the installation, piping layouts are typically represented by one- or two-line drawings, respectively. Two-line drawings are used when clearances are limited, as is the case for many shop-fabricated pipelines. The two-line drawing depicts the pipe dimensionally to scale. If the installation is simple, a one-line drawing is sufficient, with fittings, valves, and other components denoted by symbols. It is common for pipeline drawings to be shown as "developed," which assumes that the vertical pipes have been rotated into the horizontal plane, or vice versa, in order to allow the entire piping system to be displayed in the same plane. Weldolets are a type of welder. Using these small, weldable branch fittings, you can reinforce the pipe where a hole has been made without having to use additional reinforcing. Different types of these fittings are available under a variety of trademarks, including butt- and socket-welded styles, thread-on varieties, and some special designs that allow connections at elbows and other angles. Welding is a procedure. Pipe ends and flanges are prepared for butt welding in accordance with the thickness of the pipe wall. A 3/16-inch gap is left between the walls of a building that is 3/4 inch thick or less. The walls are beveled to a 70-degree included angle and a 3/16-inch gap is left between them for buildings that are 3/4 inch thick or less. A root pass, a fill pass (or passes), and a capping pass are all performed by the welder, with the filler material between passes frequently changing. For thicker walls, the pipe is tapered to a similar angle, but only up to a portion of the wall's height. In addition, a small relief angle is ground into the inside wall, which will serve as the location for a backing ring in the final product. Socket welds are typically used for thinner-walled pipes, as the name implies. It is the responsibility of an engineer to write Weld Procedure Specifications, and the welder who will be performing the welding procedure will be certified for the specific process. Pipes may need to be preheated prior to welding and then heat-treated after welding to relieve heat stress in some cases.When compared to butt-welded fittings, socket-weld fittings have a number of advantages, including the requirement for proper pipe-end preparation and the requirement for careful fit-up prior to joining butt-welded fittings. For https://www.flangeschina.com/socket-weld-flanges" style="text-decoration: underline; color: rgb(255, 0, 0); Socket Weld Flange, there is no need for a bevel, and the socket itself serves to keep the pipe aligned. The pipe must be backed out of the fitting a small amount to allow for expansion during the welding process. This is about the only special requirement there is.It is common practice to prefabricate pipeline sections (also known as "spools") inside a building, where automation can be applied to the fabrication process. Pipe joints can be rolled on slow turning machines to bring the work to the welder's station for welding. It is possible to use robot welders. Techniques such as submerged-arc welding, for example, can be used to increase productivity.As an alternative to the traditional welded piping systems, non-welded pipe fittings or no-weld pipe connectors are available on the market. When combined with cold-bending pipe or tubing, this solution eliminates the stresses placed on the pipeline as a result of the welding operation, lowers costs, and can result in a modular system that is easier to disassemble or modify as needed as a result of the welding operation.Heat welding, also known as electrofusion welding, is a method of joining plastic pipe, and HDPE pipe in particular, in a variety of configurations. Pipes can be butt-welded or socket-welded depending on their design. This is a fairly common practice in the installation of large-diameter HDPE pipe pipeline systems. For the production of these welds, a variety of specialized equipment is available.Generally speaking, when using plastic pipe and pipe fittings, it is necessary to consider pressure derating in relation to the pipe or fitting size as well as the operating temperature. When temperatures exceed 73 degrees Fahrenheit, manufacturers of PVC and CPVC materials will recommend a reduction in the pressure rating of the material. Furthermore, for a given operating temperature, pressures must be reduced even further as the diameter of the pipe or fitting grows in size. For another thing, the use of certain fittings, including but not limited to flanged joints, unioned joints, and valves, may result in lower pressure ratings than those of a straight pipe of the same diameter.