A flange kit contains everything required to install a flange onto a pipe. A flange collar, gasket and connection hardware are typically included in a flange kit. When purchasing a flange kit, it is critical to not only purchase the properly sized flange to fit the pipe, it is also important that the correct flange type be purchased to properly match the existing flange or the corresponding flange design that will make up the second half of the flanged connection.
It is occasionally necessary to remove a small section of a pipeline to install some type of connective junction, valve or gauge into the pipeline. When the situation arises, a flange kit makes the task of reattaching the pipe sections together much easier. Using the supplied flange ring, the pipe is fitted with a ring that is designed to match the flanged connector on the new piece of pipeline being installed. The flange is welded into position on the pipe, with a separate flange kit being used for every flanged connection point. Once all of the flanges have been completely welded into place, the pipeline is ready to be reassembled.
The pipeline is reconnected by placing a gasket from the flange kit between the two faces of the flange rings being connected. A bolt is then slid into a mounting hole on the flange ring, pushed through a hole in the gasket, if applicable, and then through the other flange ring. A flat washer is then slid onto the threaded end of the flange bolt and a nut is threaded onto the bolt and tightened finger tight. The washer is critical in the assembly as it prevents the nut from gouging into the flange when tightened. This process is repeated until every bolt and nut is placed into the holes surrounding the flanges.
When all of the bolts from the flange kit packages are installed, the pipe is checked visually for proper alignment. When the pipeline has been adjusted properly, the bolts can be tightened. It is typically recommended that all flange bolts be tightened in a crisscross manner to make certain the flanges are tightened straight and evenly. With some gaskets that do not include bolt locating holes, it is imperative to be certain that the gasket remains centered in the flange through all stages of connection and tightening. In order to prevent leaking connections at the flanges, any questionable gaskets should be changed and replaced with a new gasket.