Guide to Stainless Steel 304 Flanges?

What is a Flange?

Flanges are protruding ridges or rims used to increase strength or distribute the load. A piping system is made up of pipes, valves, pumps, and other piping elements that are joined together with flanges. It also makes cleaning, inspection, and modification simple. Flanges are the second most common joining method after welding.

SS 304H Flanges remain the most versatile and widely used stainless steel on the market, despite the availability of a number of alternatives. SS 304H Flanges is the most popular grade in Flanges. Grade 304 is easily formed into a variety of automotive, architectural, and transportation components. Weld Neck, Blind, Spectacle, and other types of flanges are made from this material.

Types of 304 Flanges

Flanges don't come in a one-size-fits-all package. Apart from sizing, selecting the appropriate flange design for your piping system and intended use will ensure efficient operation, long life, and the best price. As shown below, flanges come in a variety of shapes and sizes.

Slip On - Slip on Flanges are slipped over the pipe and then welded both inside and outside to provide adequate strength and prevent leakage. These flanges can have a raised or flat face. They work best in low-pressure situations. The slim and compact shape of slip-on flanges, also known as "Hubbed Flanges," makes them easily identifiable.

Socket Weld - The pipe is inserted into the flange, and the connection is then secured with a single multi-pass fillet weld. Socket weld flanges have only one fillet weld on the outside and aren't usually recommended for critical applications. Low-pressure pipes with small diameters require this type of flange.

Blind - Blind flanges have no bore because they are used to seal the pipe's end or opening. These flanges provide easy access to the pipe if work needs to be done inside the line. On vessels, these flanges are frequently used to block an unnecessary section of pipe or nozzle.

Weld Neck – Butt welding is required during installation for this type of flange. They are welded to the pipe's end to form a flange that can withstand high temperatures and pressure. The weld neck flange has a 'neck' that can move pipe tension, reducing strain in the lower part of the flange.

Threaded / Screwed - The flange bore contains a thread (female thread) that connects to the male thread of the pipe or fitting. This flange, despite its ease of use, is not suitable for high pressure or temperature applications. The main advantage of a threaded flange is that it can be installed without the use of welding.

Lap Joint - The stub end of a lap joint flange must be buttwelded to the pipe or fitting, and the backing flange must be used to complete the flanged connection. They are used in low-pressure and non-critical applications due to their low pressure holding capacity.

Spectacle – This flange is shaped like a spectacle (a pair of glasses), and it is made up of two metal discs that are connected by a metal portion. Spectacle blind flanges are used as a safety device to separate equipment or lines that need to be checked or removed from service.

Plate - Due to their shape, these flanges are also known as flat flanges, as they have a flat even surface and a full face gasket that contacts the majority of the flange surface. Flat face flanges are commonly used in applications where the mating flange or flanged fitting is cast.

Reducing - Using flanges is a type of flange that is commonly used to join pipes of various sizes in projects. It consists of a single-diameter flange and a smaller-diameter bore. When there is unpredictably changing turbulence, such flanges are avoided.

Tongue & Groove - These flanges feature matching grooves and raised sections. They have the advantage of being self-aligning and acting as an elastic buffer as a result of this.