Industrial sectors have been maximising the use of flange gasket on their tools and equipment. Flange gaskets create a static seal between two flanges faces and fill the spaces and irregularities of these flange faces. Sections of pipes predominantly utilise these flange gaskets since they can effectively prevent liquids and gases from leaking.

Flange gaskets come in a lot of sizes, inside and outside diameters, and materials. When it comes to the material, flange gaskets have three categories, namely, non-metallic gaskets, semi-metallic gaskets, and metallic gaskets. The one that is always used in low temperature and pressure applications is the non-metallic gaskets.

Properties of Non-Metallic Gaskets

Non-metallic gaskets are composite sheet materials that are commonly used with low-pressure flat-face and raised-face flanges. They can be made up of graphite, rubber, PTFE, and reinforced fibre. These gaskets can easily compress with low tension bolting. To date, these gaskets are the most affordable gasket in the market.

Non-Metallic Gaskets Classification

The classification of non-metallic gaskets is based on the material used for their production. The following are the materials used to create different types of non-metallic gaskets as well as their characteristics.

Graphite Gaskets

Graphite gaskets only use graphite with a purity of 99% elemental carbon. This material composition preference is crucial so that the performance of the gasket is maximised. Usually, graphite gaskets are used and reinforced with stainless steel inserts. Expanded metals are one of the most common inserts for these gaskets since they optimise surface pressure distribution. These expanded metal graphite gaskets can ultimately replace metallic gaskets and resist a wide range of chemical exposure.

Rubber Gaskets

Rubber gaskets, on the other hand, are cut or punched to shape from industrial manufactured rubber sheets. This type of gasket has a lot of variations that can resist different elements. There are silicone gaskets that have excellent temperature properties. Another variation is the acrylonitrile-butadiene rubber that can resist chemicals, hydrocarbons, and oil. A natural rubber variation is known for its excellent recovery properties. If you are looking for a rubber gasket that has excellent resistance to oil, ozone, and weathering, then the achlorobutadiene rubber is for you.

PTFE Gaskets

PTFE gaskets have excellent anti-stick and dielectric properties that are helpful in industrial applications. This type of gasket has low leak rates and can effectively resist different types of chemicals. PTFE gaskets have very dense sealing materials and can adapt perfectly to the flanges.

Fibre Reinforced Gaskets

The fibre reinforced gaskets are cut or punched to shape out fibre reinforced sheet materials, which usually consists of fibres, fillers, and binders. This gasket’s properties rely on the quality and composition of the aforementioned materials. Fibre gaskets can be made from different types of fibres, such as aramide fibre, carbon fibre, cellulose fibre, glass fibre, and mineral fibre. These gaskets are fairly affordable and are easy to cut or punch to size.

Non-metallic gaskets have a different type of materials used that are suitable according to your needs. If you want to enquire about the availability of these gaskets, you can contact us now at Gasketech so that we can help you out.

There are specific components that must be installed when connecting pipes, valves, pumps, and other types of piping systems. Flanges and gasket are commonly found in different types of piping systems, and that they provide easy access for maintenance, inspection, and alteration. Flanges are usually welded or screwed with the help of a gasket in between to thoroughly seal them together.

Not all flanges and gaskets are created equal. In fact, there are certain differences that flanges and gaskets possess. These differences make these components suitable for a specific situation. Flanges can be divided into two types. This division also applies to the gaskets most commonly available in the market right now.

Faces of the Flanges

The differences of gaskets lie on the type of face a flange has. There are two types of flange faces, namely, raised face flanges and flat face flanges. From the name itself, the raised face flanges have a specific part that is somehow raised on the surface. The gasket surface of the raised face flanges is slightly raised above the bolting circle face. This raised surface allows the installation of different gasket designs, including flat ring sheet types and metallic composites.

Raised face flanges are frequently used in process plant applications. The purpose of these flanges is to concentrate more pressure on a smaller gasket area, and consequently, increase the pressure containment capability of the joint.

The flat face flanges, on the other hand, have the gasket surface and the bolting circle face positioned in the same plane. This positioning means that the flat face flanges are entirely flat, making these flanges never to be bolted to a raised face flange. One type of gasket, the full-face gasket, takes advantage of this type of flange to ensure that the flanges are tightly sealed together.

The Gasket Differences

As mentioned, gaskets are extremely important since they fill the space between two or more mating surfaces. They prevent any type of leak from or into the combined objects while under compression. The most common types of gaskets are ring-type gaskets and full-face gaskets.

A ring-type gasket is placed and installed inside of the flange bolts and around the pipe bore. It has no bolt holes and is typically used on raised face flanges since it can easily sit right on top of the flange. Due to its composition, it can be installed without disassembling the joint. When buying ring-type gaskets, a supplier only requires three measurements: the inside diameter that matches the pipe bore, the outside diameter that matches the raised flange face’s outside diameter, and their thickness.

Conversely, a full-face gasket covers the entire face of the flange and is normally used on flat face flanges. Full-face gaskets are easier to install since they have bolt holes, making the insertion and alignment to the flange bolts more convenient. The only downside of using these gaskets is that the joint must be dissembled first when installing the full-face gaskets. Ordering full-face gaskets requires the following specifications: the inside and outside diameter, the bolt circle diameter, and the number of the bolt holes. Gasket thickness and the preferred pressure tolerance are also asked by the supplier.

If you want to know more about these types of gaskets, then give us a call now at Gasketech. We manufacture and supply gaskets, washers, extrusions, and mouldings for all types of industries.