1
EN 5.127.3/04.21
Proportional
Flow Controller
poppet type, pilot-operated
normally closed
UNF Cartridge – 350 bar
PWS08Z-01
up to 55 l/min
up to 350 bar
The proportional ow controller is a pilot-
operated, normally closed, spring-loaded
poppet-type ow control valve.
It is non-compensated and its function is
to smoothly control the ow from port 2
to port 1.
The energization of the coil opens
the pilot stage and oil ows across an
orice to the back of the main piston.
The resulting pressure dierential
causes the main piston to follow the pilot
stage. When combined with a pressure
compensator the proportional ow
controller can be used as a 2-way ow
regulator – for example when required
to lift/lower variable loads at the same
velocity.
FEATURES
z Stepless adjustment of the ow, depending on the coil current.
z Excellent stability throughout the entire ow range
z Excellent dynamic performance
z On request: mechanical adjustment of one point of the curve
(Version 01, without option M)
z Optional: Soft shift function with extended switching times possible
z Exposed surfaces zinc-nickel plated for increased corrosion protection
(1000 h Salt spray test)
FUNCTION
SPECIFICATIONS*
Operating pressure: max. 350 bar
Nominal ow: max. 55 l/min
Internal leakage: leakage-free
max. 5 drops/min (0.25 cm³/min)
at nominal pressure
Media operating temperature range: min. -20 °C to max. +100 °C
Ambient temperature range: min. -20 °C to max. +60 °C
Operating uid: Hydraulic oil to DIN 51524 Part 1, 2 and 3
Viscosity range: min. 10 mm²/s to max. 420 mm²/s
Filtration: Class 19/17/14 to ISO 4406 or cleaner
MTTF
d
: 150 - 1200 years,
according to DIN EN ISO 13849-1
Installation: No orientation restrictions
Material: Valve body: steel
Piston: hardened and ground
steel
Seals: NBR (standard)
FKM (optional, media
temperature range
-20 °C to +120 °C)
Back-up rings: PTFE
Coil: steel / polyamide
Cavity: FC08-2
Weight: 0.5 kg
Electronic data
Control current: 850 mA, 18.0 Ohm (24 Volt)
1750 mA, 4.1 Ohm (12 Volt)
Dither frequency: 120 Hz – 250 Hz (120 Hz recommended)
Hysteresis with dither: 4 - 6% of I
nom
Repeatability: ≤ 1.5 % of I
nom
Reversal error: ≤ 2 % of I
nom
Response sensitivity: ≤ 1 % of I
nom
Type of coil: Coil (12 or 24) P...-50-1836
NOTE
In order to achieve optimal function, any trapped air should be vented using the bleed
screw on the face of the pole tube.
* see "Conditions and instructions for valves" in brochure 53.000