By Ivy Max
A flange is a component used by plumbers when they need to join piping together. Welding is also used for this purpose. Flange use allows the piping to be disassembled easier if the need arises. Flange connections are composed of the flange itself, and specific gaskets, and bolting to go along with it. Stainless steel is widely used, but flanges can come in many other materials. Different materials can be used depending on one’s plumbing needs. It is important to be sure what type one will need for the job. Making the right decision will ensure many years of problem-free plumbing.
Some of the different types of flanges that plumbers can use are as follows. Some flanges are threaded and are called Threaded Flanges. They can also be called Screwed Flanges. The thread from the pipe is mated up with the thread in the flange. In this situation, welding is not necessary. Screwing the two together makes for a good, tight fit. The Slip-On Flange is used for high flow rate systems. Once the piping is connected a filet weld is required to properly secure the piping.
Socket-Weld Flanges are used in smaller, lower pressure types of piping. A filet weld is also required in this type of flange. Lap Joint Flanges are used in situations where physical space is limited. It is good for situations that require regular maintenance. Weld Neck Flanges are used in plumbing systems that handle high pressure and temperatures. Some butt welding is required in the installation process. Blind Flanges are used where piping systems end. They are used to seal the ends of the pipe. Specialty Flanges are used when other types of flanges will not solve the situation the plumber is working on.
There are different types of facing that are used in flanges. There is the Flat Face and Raised Face. Ring Joint Facing is for high pressure and temperature systems. Tongue and Groove Facing Flanges have matching sections. Their groves and raised sections are the same. This aids in the alignment process and provides ample room for gasket adhesive. Male and Female Facing Flanges work like Tongue and Groove. The difference is male and female flanges can produce placement options that are more accurate and it allows for additional options for gasket materials. Face types can also come in a smooth or serrated surface. Metallic gaskets work well with a smooth face. Gaskets using softer types of materials work best with the serrated face.
Flanges are designed in many different sizes and measures of thickness. The measurement of the outside diameter is the amount of distance between the two opposing edges of the face of the flange. A measurement of the thickness of the material is important along with flange
dimensions. Bolt distancing needs to be considered. The size of the piping is also important. The piping size and flange size have to match up exactly. The size of the bore being used can vary. Here’s where flange dimensions also come into play.
Flanges receive certain classifications. The classification helps plumbers to know what type of flange and flange dimensions are needed. Temperature tolerance and ability to handle pressure are measured. This is how flanges are classified. Flanges are assigned certain numbers and a suffix. This is one way the proper flange for the job is chosen.
Global standards are in place for flanges. Markers are placed on all flanges. They include a code or logo associated with the manufacturer. They can have certain codes and grades for the type of material used. There is a rating associated with how much pressure a flange can handle. The size is noted. There is a heat number assigned. Other specifications might appear on the flange labeling.
