Safety Instructions - HYDAC International FPU Instrucciones De Servicio

4. Pre-charge pressures
NOTICE
Always comply with limits given in overview
brochure
"HYDAC Accumulator Technology"
No. 3.000
4.1. Temperature effect
So that the given pressures are not exceeded,
the pre-charge pressure p
at charge temperature:
p = p
0 (t ) 0 (t
0 2
t = pre-charge temperature [°C]
0
t = max. operating temperature [°C]
2
p = pre-charge pressure [bar]
0
For values, see fold-out page, Table 2 I.

4.2. Safety instructions

DANGER
Prior to each testing procedure, and before
topping-up or re-charging with nitrogen, the
hydraulic accumulator must be isolated from
GB
the pressurized system by means of a
shut-off valve and the fluid released.
Ensure adequate ventilation when
discharging nitrogen from hydraulic
accumulators in enclosed spaces.
Risk of suffocation.
NOTICE
FPU-1:
If the gas pressure in the nitrogen bottle is
higher than the max. permitted operating
pressure of the hydraulic accumulator, a gas
safety valve or pressure reducer must be
installed upstream.
FPU-2:
When charging by means of an intensifier, it
is essential that the max. operating pressure
of the hydraulic accumulator is not exceeded.
44
must be determined
0
t + 273
0
• bar
t + 273
)
2
DANGER
Risk to health when using aggressive
fluids (we recommend using special
charging and testing units)
When charging or testing the hydraulic
accumulator, nitrogen and operating fluid can
escape if the bladder, diaphragm or piston
seals are faulty (i.e. leaking).
NOTICE
When charging using an intensifier or nitrogen
charging system connected upstream,
continuous operation can lead to
unacceptable increases in temperature. Rest
periods must therefore be incorporated into
the charging procedure and the FPU allowed
to cool down.
WARNING
FPU-1:
Removal of the check valve (C) is not
pemitted. The valve has a safety function for
the entire FPU-1.
NOTICE
For drawings referred to in the text, see
fold-out page.