Storage Tanks
The preferred material
of construction for hydrogen peroxide storage tanks of all concentrations is 5254
aluminum. Alternate materials of construction
are 304L or 316L stainless steel. All
materials handling hydrogen peroxide will need to be cleaned and passivated to remove dust
and dirt and to create an inert surface prior to being placed into service. A solution of 30 to 50% nitric acid is used to
passivate the surface of all equipment.
Piping Systems
Piping for hydrogen
peroxide can be constructed of 304L or 316L stainless steel. Aluminum piping (grades 1060 or 1100) is also
acceptable. Flanged connections are preferred
over threaded connections. Stainless steel is
preferred over aluminum because stainless steel piping is more readily available, easier
to weld and repair.
Piping should be
designed to minimize the number of valves and thus avoid trapping hydrogen peroxide
between valves. Where hydrogen peroxide can
be trapped between two valves, a pressure relief valve should be installed to excessive
pressure build up in between the valves. The
discharge of the relief valve should not be directed to the storage tank because of the
possibility of contaminating the hydrogen peroxide in the storage tank.
Gaskets for flanged
connections should be PTFE.
Valves should be
constructed of 304 or 316 stainless steel with PTFE packing. Valves with an internal cavity such as ball valves
should have the ball drilled on the upstream side to vent the cavity when the valve is
closed.
Pumps
Pumps should be
constructed of 304L or 316L stainless steel.
Centrifugal pumps should
be either sealless or equipped with a mechanical seal of stainless steel with glass-filled
PTFE and ceramic faces. If a seal flush is
required, hydrogen peroxide should be used.
Metering pumps should
have PTFE diaphragms with the body constructed of stainless steel.
