Application
To
minimise risk of damage to tanks due to overpressurising
or liquid
overfilling.
Construction
The dead weight pressure
relief valve is available in two versions:
. Integrated in to a SCANDI BREW®
tank top system
. Mounted on its own counterflange
The advantages of an
integrated pressure relief valve are
lower initial costs, superior hygiene
and smaller area required
to seat valve.
The valve is available in the
following sizes:
Diameter Operation Range
75 mm 1.0 - 3.0 bar (15 - 40
psi)
100 mm 0.5 - 2.0 bar (7 - 30 psi)
125 mm 0.5 - 1.5 bar (7 - 22
psi)
150 mm 0.5 - 1.0 bar (7 - 15 psi)
The size and setting of the pressure relief valve is based
on
the tank design data and process requirements.
The preset opening
pressure of the valve is normally at least
10% above maximum tank working
pressure.
The pressure relief valve is produced in a sanitary and
robust
design.
Materials
All metallic parts: Stainless
steel AISI 304
(or acc. to customer specification)
O-ring seal: NBR
All
other parts: Non-toxic foodgrade materials.
Generally, to offer full protection against
overpressurising and
liquid overfill, the active diameter of the pressure
relief valve
should correspond to the tank inlet size. Heating
elements
are available for valves exposed to sub-zero temperatures.
A heating tape is supplied for the flange mounted
valves,
whereas valves integrated in a top plate are heated by means
of
heating blocks mounted on the top plate close to the valve.
Operation
The pressure relief valve is
delivered with counter weight set
to suit customer requirements as to opening
pressure. When
pressure in the tank exceeds the preset opening value
the
valve relieves the excess pressure.
Cleaning
It is important that the valve
seat is kept clean. Assuming the
valve is operating normally, the valve disc
is satisfactorily
cleaned during tank CIP cycle.
The pressure relief valve
can be supplied with a pneumatic
force opener.
Alternatively, the valve
can be supplied with a built-in CIP
nozzle for separate cleaning of the valve
disc. This is recommended
when the tank cleaning head will not guarantee
satisfactory
cleaning of the disc.
Mounting
The pressure relief valve
should be seated horizontally.
An inclination of max. 10° is acceptable but
the lever arm must
then point in to the centre of the cylindro-conical tank
top.
Benefits
. Valve seat design ensures operational
reliability
. Sensitive set points for precise operation
. Fully cleanable
with integrated CIP system
. Minimal and low-cost maintenance demand
Maintenance
Requires periodic manual
cleaning of the valve assembly and
test of the function.
O-ring replaced
every 3-5 years. With heating elements the
O-ring is replaced every 2-3
years.
Approval
PED approved.
Extra Equipment
. Heating elements for
valves exposed to sub-zero
temperatures
. Built-in CIP nozzle incl.
flexible stainless steel
CIP feeding pipe
. Pneumatic force opener
.
Proximity switch with mounting fitting for signalling if the
valve has been
in operation
. Splashguard
. Weather cowl
