E 3.100.23/04.09
53
1. DESCRIPTION
1.1 FUNCTION
Fluids are practically incompressible and
cannot therefore store pressure energy.
The compressibility of a gas is utilised
HYDAC diaphragm accumulators are
based on this principle, using nitrogen as
the compressible medium.
A diaphragm accumulator consists of a
diaphragm acting as the gas-proof screen.
hydraulic circuit so that the diaphragm
pressure increases and the gas is
compressed. When the pressure drops,
the compressed gas expands and forces
At the base of the diaphragm is a valve
poppet. This shuts off the hydraulic outlet
empty and thus prevents damage to the
diaphragm.
NOTE
Pressure Equipment Directive
PED 97/23/EC and the German industrial
z
No. 3.551
Hydraulic
Diaphragm Accumulators
HYDAC diaphragm accumulators
1.2.1 Weld type
z
on the gas side or, alternatively,
completely sealed. Fluid connection
available in various types
z
and gas sections
valve poppet set into the base of the z
diaphragm
1.2.2 Screw type
z
connection
z
connection
z
vulcanized valve poppet set into the z
base of the diaphragm
z
sections of the accumulator together
valve poppet
valve body
diaphragm
pressure vessel
valve poppet
valve body
diaphragm
pressure vessel
1.2.3 Diaphragm materials
The diaphragms are available
NBR (acrylonitrile butadiene rubber, z
PERBUNAN),
IIR (butyl rubber), z
z
®
),
ECO (ethylene oxide z
epichlorohydrin rubber).
The material must be selected according
temperature.
must be made for the fact that the gas
elastomer temperature if there are adverse
discharge conditions (high pressure ratio
p
2
/p
0
, high discharging velocity). This can
cause cold cracking in the elastomer.
The gas temperature can be calculated
1.2.4 Corrosion protection
corrosion protection, such as plastic
coating or a galvanic or chemical surface
all types can be supplied in stainless steel.
contamination collecting, a vertical position
bottom).