Material Compatibility with Hydrogen Peroxide
Materials.
Materials used in the construction of containers or
other equipment should
be chosen with great care. The suitability of some
common engineering materials is
discussed here. Instructions for welding and
passivation are provided for aluminium
and stainless steel.
Aluminium - The aluminium must be highly pure (at least
99.5% to 99.7% AI, Aluminium Association Designations 1060,1260,5254,5652).
Aluminium can be used for manufacture of both tanks and pipes. However, for
fabrication related reasons, aluminium is usually used only for tanks, while
stainless steel is used for piping. TIG (tungsten metal-are) or MIG (gas
metal-arc) welding with shielding gas (e.g. Argon) must always be used for
aluminium welding. Tungsten electrodes should be used for TIG welding. It is
important that the filler metal has the same composition as the base metal
and be free from moisture and other impurities. A high degree of cleanliness
must be observed during fabrication to make sure no dirt or other organic
matter becomes absorbed into the aluminium. Tools and cleaning equipment
should be plastic or stainless steel.
Aluminium equipment must always be pickled and passivated before being
filled with
hydrogen peroxide.
Stainless Steel - This is the most suitable material for H2O2
equipment. It is recommended that instruments, piping and the like be made
of stainless steel equivalent to grade AISI 316L (SIS 2353). Pumps should be
AISI 316. This material can also be used for tanks and mixing vessels. When
possible,TIG welding with shielding gas should be used. The piping must be
well filled with shielding gas to ensure a good weld on the inside. A
properly executed TIG-welded pipe joint does not need to be pickled on the
inside. Cleaning with water and passivation with hydrogen peroxide are
sufficient. If it's determined that the piping does need to be pickled, it
must be done with nitric acid. Make sure steel plates are protected during
the fabrication.
Stainless steel tanks must be cleaned and pickled before final passivation
with hydrogen peroxide andlor nitric acid. Contact Eka Chemicals for
additional information about passivation of new equipment.
Plastics
- Certain plastics like HDPE can be used for equipment. However, with
plastic there is a greater risk of damage in the case of a collision and
because of ageing of the material. Care should be taken to position or
install a plastic tank to protect it from collision and possible rupture.
Fluoropolymers, such as Teflon® (TFE) and Viton®, are
other appropriate materials to use with hydrogen peroxide. Gaskets and seals
should preferably be made of these materials or of polyethylene,
uncompounded PVC or silicone rubber.
Polyester - Unsuitable in prolonged contact with
hydrogen peroxide,
Glass and Porcelain - These materials are reserved for
use in the laboratory.
It is strongly recommended that hoses should be steel-reinforced
chlorosulfonyl polyethylene (HYPALON®), PVC or cross-link
polyethylene lined.
Cleaning And Passivation Are Important. All materials that come
into contact with
hydrogen peroxide must be thoroughly cleaned and
passivated. No materials other
than those mentioned here should be used without
first consulting Eka Chemicals.
Always contact Eka Chemicals prior to initiation of projects involving new
construction or revisions to hydrogen peroxide- related processing
facilities.
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