Flange for piping is one of the important mechanical element in the piping system to join pipes, it is a way or component used to connect piping accessories such as pipes, pumps, valves, etc. All of these components are interrelated in order to achieve a workable result for the whole system. The flange can also provide us easy access to the piping system for cleaning and inspection purpose. Flanges are available in a wide range of materials, sizes, designs, shapes, and specifications to match our requirements and project needs. Stainless steel flange is considered one of the most common types of flanges. Other common materials of flange include cast iron, plastic, brass, aluminum, forged carbon steel, and many other available depending on your application. For example, the ASTM A 105 is carbon steel flanges for high-temperature, ASTM A694 is high yield carbon steel flanges used for pipes lines, and ASTMA 182 is stainless steel flanges. For different application purposes, the flange can be painted, internally lined, or even coated to enhance its durability and functionality. We normally will select the material of flanges based on the material of pipe and make sure they are in the same material. Here we will introduce some of the basic functions and different types of flanges for piping in the Malaysia Market.
When choosing the right flanges, it mainly depends on the system that you want to use the flange and the specific requirements. The right selection of flange can help us to ensure a longer usage life, reliable and smooth operation at optimal cost. Flanges are usually to be screwed or welded and with a gasket between the flange to provide a seal. Few common types of flanges are available below:
1. Threaded Flanges
Threaded flanges have a thread inside which use to fit with the male thread of the pipes or fittings, the connection of pipes is done by screwing the flanges on pipes and without the necessity of welding. Small welds may be required to strengthen the connection with pipes. Although threaded flanges are available in multiple sizes and pressure ratings, it is normally used for smaller pipes with no more than 2 inches and wall thickness more than schedule 80. We will also found threaded flanges to be used in gas stations, plants or explosive areas as welding is dangerous to be performed in these areas.
2. Socket-Weld Flanges
The connection of pipes with the socket-weld flanges is done with a single fillet weld at the outer surface of the flange. The pipe shall be inserted in the socket of the flange until it reaches the bottom of the flange, and then withdraw it by 1.60mm to avoid direct contact between the end of the pipe and shoulder of the socket, the creation of a gap is for proper positioning during solidification of the weld metal. This type of flanges is normally used for small size and high-pressure piping system which does not carry corrosive fluids as it is easy to be corroded in the gap area.
3. Weld Neck Flanges
This kind of flanges has a long tapered hub which is able to provide critical reinforcement when using in an application that involves high pressure, variable force, repeating bending or under extreme temperature such as a sub-zero environment. These flanges will have to match with the inside diameter of the pipe or fittings to make sure no restriction in the system flow. The pipe to be welded to the collar of the flange with full penetration. Due to its high performance, weld neck flanges are a popular choice for process piping systems and also a costly product.
4. Slip-on Flanges
The slip-on flange is using two fillet welds to connect pipes & fittings and its bore size has to be larger than the outer diameter of the connecting pipes. By matching correctly with the flange and pipes, the pipe can slide inside the flange and then connected by the execution of fillet welded from both inside and outside. The slip-on flange is available in a large range of sizes and uses for a higher flow system. In comparison with the weld neck flanges, Slip-on flanges have a shorten usage life under the same mechanical environment and conditions.
5. Lap Joint Flanges
The lap joint flange has a flat surface and together with stub ends used in conjunction with the connection of pipes. It requires butt welding on the stub end to the pipes and the flange will create a flanged connection that is freely moved over the pipe. The material of the lap joint flange is normally in a lower grade of material, while the material of the stub end will be the same material as the pipes. The use of lap joint flange can reduce the overall cost and easy for the required dismantle and maintenance.
6. Blind Flanges
A blind flange is a blank disc with bolt holes and it does not have a center hole. It is normally used to isolate or terminate the piping system, seal at the end of the piping, or as a manhole cover in the vessel. The blind flange is the most highly stressed type and has to withstand remarkable mechanical pressure. It can be easily unbolted when necessary and allow the operator easy access to the pipeline.
7. Specialty Flanges
Other uncommon flanges such as weldoflanges, reducing flanges, nipoflanges, expanding flanges, or long weld neck flanges are available in the market to meet a wide range of uses and environmental conditions.
We also can classify the types of flanges by its facing as the facing type can have a critical impact on the performance and service life of the flanges. The types of its facing will determine the use of the gasket as well. Few common facing types available such as Flat Face, Raised Face, Ring Joint Face, Tongue and Groove, Male & Female types. Flat face with an even surface with the need of combining with full face gasket. Ring Joint Face can be used in high pressure and temperature operation. The flange faces can be either serrated or smooth types which depend on the types of gasket and fluids. A smooth finish is used together with a metallic gasket whereas a serrated finished is used with a non-metallic gasket.
MecHero Malaysia supplies different types of flanges for piping systems in residential or industrial applications in Malaysia. You can always contact us at +6011-7000 7687 or email us at my.mechero@gmail.com for the inquiry. Tell us your requirements now and we can advise you accordingly.
