Manway gasket
Manway gasket
Stainless steel manway gaskets physically mediate between the flange and the manway lid and are designed to keep the unit tight when the lid is properly closed. High-quality plastics are used for gaskets – the most common are: EPDM, silicone, FPM/FKM, neoprene, NBR and PTFE. Elastomers for direct food contact additionally meet the stringent hygiene requirements of FDA guidelines and EU regulations (1935/2004/CE).
Composite or hybrid gaskets are found in some manway models. The core and the outer shell of such a gasket are made of different materials. An example of such a product is the FEP-silicone gasket, where a silicone core is coated with FEP. This type of solution makes it possible to combine different material properties, such as chemical resistance and high temperature resistance.
The selection of a manway gasket depends on several parameters – the most important include:
The first two parameters (i.e.: the type of medium and the manway operating temperature) translate directly into the selection of appropriate gasket material, which must maintain resistance to prolonged exposure to the process medium. The remaining parameter (method of operation) will translate into the preferred form of gasket installation in the manway.
The evaluation of the aggressive and corrosive properties of the process medium (liquids, fluids) and the operating temperature should be considered in conjunction when selecting a manway gasket. This means that the manway gasket should be able to withstand both the aggressive effects of the process medium and the operating temperature. Only if both criteria are met simultaneously, will the gasket be functional, safe to use and not degrade quickly.
The method of operation of the manway, which translates into the form of installation of the gasket in the manway, determines one of two options for the location of the gasket:
If there are frequent operations at the manway (for example, pouring additional substances into the tank through the manway), it is recommended to use manways with a lid-mounted gasket. This allows to avoid potential mechanical damage to the gasket.
It is worth noting that this does not apply to pressure manways where the predominant method of gasket installation is on the manway frame.
Aseptic gaskets are characterized by a special design (profile). The design of these types of gaskets is subject to strict requirements in order to meet the appropriate hygiene standards, applicable in the processes of manufacturing medicine, cosmetics and products for direct human consumption.
We use cookies