Correct installation is the main requirement for the reliable
functioning of a gasket. The bolts and the surfaces to be sealed must be
selected according to the surface pressure (minimum required and maximum
permissible) for the respective gasket.
- Only new, undamaged, and dry gaskets should be used. Observe the storage
conditions (see below).
- Clean the sealing surfaces carefully, without scratching them. Make sure that
the sealing surfaces are dry.
- Position the gasket centrally; do not apply any supplementary media (grease,
releasing agent, or sealing compound) to gaskets or sealing surfaces.
- Do not use corroded bolts, nuts or washers. The calculated surface pressures
must coincide with the achieved pressures, therefore the bolts and nuts should
be lubricated lightly.
- Mount the second sealing surface parallel to the first surface, and tighten the
bolts by hand.
- In order to achieve an even distribution of surface pressure, the bolts must be
torqued to the specified value "crosswise" and using at least 3 steps. Example:
Step 1: 20 % of the specified torque.
Step 2: 60 % of the specified torque.
Step 3: 100 % of the specified torque.
- All bolts must reach the same specified torque.
- Every gasket settles, especially after a longer period without loading. Therefore, the bolts should be retorqued to 100 % before commissioning.
- Retorquing of fiber or PTFE-based gaskets that have already reached a higher
operating temperature should only be done in the cold condition with great care
and also in several steps, because there is a risk of destroying the gasket
(especially with fiber gaskets that have hardened).
Storage conditions for fiber-based gaskets and gasket material sheets (FA to
Maximum storage period is two or three years under the
Any large deviation from the above will reduce the permissible storage period.
In case of critical (e.g. toxic) gases, the storage period should not exceed one
year. If necessary, the gaskets or gasket material sheets must be sealed in
airtight and lightproof wrappings.
- Temperature: below 20 °C
- Relative humidity: 30...60 %
- No direct sunlight
- No artificial lighting with high UV content
- No ozone
- Stress-free storage
Fuji films for determining surface pressure
The Fuji "Prescale" film
is ideally suited for the simple determination of the achieved surface pressure
with flat gaskets, and its distribution over the sealing surface.
Depending on the sensitivity of the selected film, surface pressures between 0,2
N/mm2 and 130 N/mm2 are represented by different shades of red color. Fuji
"Prescale" film can be ordered from: REINZ-Dichtungs-GmbH.
Give us a call under ++49 (0)731 7046-777.
Frequently, there are applications in which
simple, punched gaskets are not sufficient.
Especially with molded seals or gaskets for covers and housings, only a low
surface pressure is possible, so that even very soft gasket materials are not
compressed sufficiently. By means of screen printing, an elastomer bead is
deposited on both sides of the gasket. Consequently, the bolt force is
concentrated at these points, whereby the gasket is compressed sufficiently to
provide a reliable seal. The same effect is achieved with the beaded, elastomer-coated
metal gaskets MatriCS and RETALL.
In particular with media that are sensitive to contamination, or for increased
sealability (especially with graphite), blow-out safety or chemical resistance,
flange gaskets with an internal metal bead (preferably of stainless steel) are
used. Such beaded gaskets require higher surface pressures during installation.