Fulton FB-S Horizontal Firetube Boiler - Manual (Page 64)

The Fulton Companies*FB-S Series Manual*Version 2010-0820 rev. 3/5/13
Page 64
Caution
TOPOG-E gasket have a finite life after installation and must be
renewed annually. It is important that the instructions given in this section
are adhered to.
The boilers are fitted with TOPOG-E gaskets in all the inspection holes of the
boiler. These gaskets work very well and millions have been safely used over the
last 30 years, however, it is absolutely essential to observe a few simple rules in
order to get the best performance from your installation. Elastomeric Vulcanizates,
which form the basis of TOPOG-E gaskets, undergo degradation from many
sources including heat, oxygen, stress, and overdosing from certain types of water
treatment. This takes the form of material oxidation, hardening/embrittlement and
cracking which may result in gasket failure. Steps must be taken to minimize the
effects of such attacks.
Water treatment and oxygen attack can be combated by ensuring that the gasket is
aligned correctly so that only the extreme edges of the gasket are exposed. If a
new gasket leaks after fitting this is almost certainly due to incorrect sealing or
alignment. Incorrect sealing or misalignment will reduce the life of the gasket and
cause problems later.
Under stress can be avoided by tightening just sufficiently to stop any leakage
when fitting cold and before firing the boiler. Fire the boiler and then gradually
warm the boiler up, allowing the increasing steam pressure to take over and
complete the seal. The will allow the gasket material to contract naturally and
follow the topography of the mating surfaces. The securing nut can then broken
when the boiler is cold and under negative pressure.
Gentle warming of the boiler on initial firing after maintenance will also help to
ensure that the rubber ‘cures to shape’. If the rubber post-cures, the elastic
memory will be destroyed and any initial over-tightening will cause the gasket
to become hardened and embrittled, leading to cracks and eventual failure.
Fitting Instructions
Blowdown the boiler completely and examine all inspection holes in the boiler. If
any leakage is evident, proceed as follows:
a) Remove the old gasket and thoroughly clean the mating faces of the cover plate
and boiler ring.