RADCOFLEX offers a complete range of fabric and metal
Where the medium to be conveyed is likely to include
particles of rock, heavy dust, or flyash, RADCOFLEX highly recommends the
inclusion of flyash seals or bolsters to help minimise the build-up of debris
that could inhibit the expansion joint’s movement.
Flyash seals are selected depending on the system
temperature and media, and are used in two basic configurations: the flyash
seal and the bolster.
The flyash seal, which consists of a thin, flexible material
such as fabric, wire mesh or high alloy metal sheet, is used in a variety of
environments where a barrier is required around the entire perimeter of the
The bolster, which fills the entire cavity with a material
less dense than flyash is commonly used on high temperature dry systems, or
where flyash accumulation is only a problem on one side such as the bottom of a
Liners and flyash seals are not leak-tight, and serve to
minimise the build-up of flyash, rather than prevent it entirely. Minor ash or
dust particles may penetrate, but usually not to a damaging degree.
The service life of the gas seal membrane and flyash seal
depends on the severity of the media, materials of construction, and method of
installation. Liners and flyash seals are introduced to help prolong the life
of the gas seal membrane element. When the gas seal membrane is ultimately replaced,
any accumulated flyash should be removed and a new flyash seal installed.