By John Arthur 
Gaskets are a critical element in most engineering and manufacturing uses, as they are seals to provide leak-tight contact between connecting surfaces. A choice of a gasket has to be taken into consideration because it has a direct impact on your equipment performance and lifespan. This guide briefly summarises three common types of gaskets—sheet gaskets, moulded gaskets, and O-rings—separating their definitions, advantages, disadvantages, and applications.
Sheet Gaskets
Sheet gaskets are flat seals that consist of an assortment of materials such as rubber, graphite, PTFE, or composite fibres. They are usually punched or cut out of big sheets and are suited for sealing flat surfaces.
Sheet gaskets possess one of the biggest advantages of flexibility. They can be fabricated to custom specifications and fit size exactly, offering a low-cost solution to many static sealing situations. They are simple to manufacture and widely available, and this is the reason why they are the industry first choice for chemical processing, oil and gas, and water treatment industries.
Sheet gaskets are not however without their limitations. They are not typically the best choice for use in the event of extreme pressure or temperature change, since their material may not withstand severe conditions. Their flat shape may also not be as effective in the event of scenarios where flexibility and three-dimensional sealing are needed.
Moulded Gaskets
Moulded gaskets are manufactured by pressing or injecting material into a mould in order to gain a very accurate shape. They are most commonly made from elastomers like rubber, nitrile, or silicone, but thermoplastics and other specialist materials are used.
The greatest advantage of moulded gaskets is that they can produce bespoke sealing shapes, ideal for irregular or complex surfaces. Their precision-crafted design gives an even seal, even on dynamic or high-pressure applications. Moulded gaskets are used extensively by automobile, aeronautical, and medical equipment industries for their speciality equipment.
Moulded gasket manufacture, in contrast, takes more time and capital, especially in low-output work. Tooling makes it an uneconomic choice where end applications do not require a great degree of accuracy or customisation. Material constraints may also rule them out in particular situations, i.e., where high thermal stability is required.
O-Rings
O-rings are donut-shaped ring seals with a cross-section, typically produced from elastomers such as EPDM, nitrile, or silicone. They are typically straightforward and efficient in leak prevention for dynamic and static purposes.
One of the standout features of O-rings from Gulf Rubber and others is their ease of installation. They provide a stable seal under pressure, and they are perfectly geared for hydraulic and pneumatic usage. They are small and cheap, making them a favourite choice for industries across the board, from automotive to manufacturing.
But there are weaknesses with O-rings. They will be confined to round applications for the most part and will fail under a high-pressure or high-temperature setting unless outstanding materials are employed. Moreover, when they are not installed properly, they can malfunction through tearing or pinching, which will render their seal mechanism useless.
Final Thoughts
Ideas of the differences among sheet gaskets, moulded gaskets, and O-rings help engineers and manufacturers to select accordingly for application. All three are different in strength and absence, thereby being more suited to a specific task. To work with static seals, delicate surfaces, or dynamic pressure systems, good gasket selection enhances performance, reduces maintenance, and delivers reliability.