01
Manifold blocks
Designed in-house. Cartridge, subplate and proportional valves share one block: fewer pipes, fittings and leak points.
[HPU]Design · build · test · commission
Hydraulic power unit manufacturer: units built as systems, not boxes.
Soydan engineers and manufactures hydraulic power units in İzmir — from compact single-pump OEM units to redundant fleets for steel plants running 24/7. Manifolds, valve stands, electrical panel and PLC/SCADA come from the same floor, and every unit passes a factory acceptance test before it ships.
[01]Scope
One supplier, whole system.
| Scope item | How we do it |
|---|---|
| Circuit & system design | Hydraulic circuit, component sizing and 3D layout by in-house engineering — from application data sheet or a problem description. |
| Manifold blocks & valve stands | Manifolds designed in-house; valve stands piped, wired and function-tested before shipment. |
| Reservoir & frame fabrication | Tanks and frames welded in-house under EN ISO 3834-2, painted to customer RAL. |
| Electrical panel, PLC & SCADA | Control panels and automation software built with the hydraulics, not after it — one supplier, one interface. |
| Factory acceptance test (FAT) | Every unit runs on the test floor before dispatch — customer witness welcome at the İzmir works. |
| Pickling, flushing & commissioning | Pipework cleaned to the specified ISO 4406 cleanliness class; site installation and start-up by our own field teams. |
Component base: Bosch Rexroth, Parker, Sun Hydraulics, Hydac and the rest of the twelve-brand portfolio — selected per application, never forced to one catalogue.
[02]Components & brands
What goes into a power unit.
Everything sits on one frame, connected to the machine by pressure and return lines and a power supply.
| Component | What it does | Source |
|---|---|---|
| Reservoir | Stores the oil; lets it shed air and heat while dirt settles. | In-house, welded under EN ISO 3834-2 |
| Motor-pump group | Gear, vane or axial-piston pump, fixed or variable displacement. | Bosch Rexroth; Settima Meccanica low-noise screw pumps |
| Valves & manifold | Relief, directional, proportional and servo valves in one manifold block: less piping, fewer leak points. | Bosch Rexroth, Parker, CBF Hydraulic; Sun Hydraulics cartridges in manifolds we design and build |
| Filters & cooler | Keep the oil clean and at working temperature; off-line loop on 24/7 units. | Hydac |
| Accumulators | Cover peak flow and allow a safe stop on power failure. | Hydac |
| Instruments & panel | Pressure, level and temperature signals; motor starter, PLC and SCADA link. | Hydac sensors; panel in-house |
Brand pages: Bosch Rexroth · Hydac · Sun Hydraulics · Parker · Settima Meccanica · CBF Hydraulic. Spares for an existing unit? Send us the code via the part-number lookup.
[03]HPU design & calculation
Sizing starts with the job.
A pump makes flow; the load creates the pressure. So design starts at the actuators: what force, at what speed, how often. These rules give a first sizing only.
P [kW] = p [bar] × Q [l/min] ÷ (600 × η)
P · motor shaft power
p · working pressure
Q · pump flow
η · overall pump efficiency (about 0.80–0.90)
Q [l/min] = 6 × A [cm²] × v [m/s]
F [kN] = p [bar] × A [cm²] ÷ 100
- Flow and pressure. Worked example: a Ø100 mm bore at 0.1 m/s needs about 47 l/min, so 50 with leakage. For 150 kN it needs about 191 bar, so 200 bar after losses.
- Motor power. In the example, 200 × 50 ÷ (600 × 0.85) ≈ 19.6 kW, so the next standard motor: 22 kW. If pressure and flow peak at different times, size for the highest p × Q point; a double pump, power-controlled pump or accumulator allows a much smaller motor.
- Reservoir. For stationary plant, 3–5 times the pump flow per minute (150–250 litres at 50 l/min in the example), plus 10–15% air space.
- Cooling. For a first estimate, take 25–30% of installed power as heat load. Keep the oil at 40–55 °C; above 60 °C, oil and seal life fall fast.
- Filtration. The most sensitive component sets the ISO 4406 target: typically 16/14/11 or cleaner for servo valves, 18/16/13 for proportional valves, 19/17/14 for general circuits, 20/18/15 for simple gear-pump circuits.
The worked example is illustrative, not from a real project. The component maker's cleanliness class is binding.
[04]Unit types
Catalogue unit or custom power pack?
| Criterion | Catalogue unit | Custom unit |
|---|---|---|
| Starting point | Catalogue tank, motor and pump combination | The machine’s duty cycle and plant specification |
| Typical duty | Simple machines, intermittent use | Presses, lines, process plant; continuous or 24/7 |
| Pump & control | Fixed gear pump, on/off valves | Variable pump, proportional or servo valves, accumulators |
| Cooling & filtration | Often a return filter only; cooler optional | Sized to the heat load and ISO 4406 target |
| Redundancy | None | Standby pump group, duplex filters |
| Records | Catalogue sheet | FAT record, circuit diagram, 3D model, component list |
A catalogue unit often suffices for a few minutes a day on one cylinder. Go custom when cycle time sets output, the unit runs 24/7 or proportional or servo valves are involved. We size every unit to its application.
[05]HPU manufacture & testing
From manifold block to acceptance record.
02
Valve & accumulator stands
Piped, wired, gauged per station and function-tested. Accumulator stands get safety and shut-off blocks and are pressure-tested.
03
Panel & PLC
Sequences are written by engineers who know the circuit. On compact units the cabinet can sit on the frame.
04
Factory acceptance test
Every unit is started and function-tested in İzmir; fleets are tested together. The test record is part of the documentation.
05
Pickling & flushing
New pipework is acid-pickled and flushed to the specified ISO 4406 class; proportional and servo systems are superflushed with temporary flushing plates.
06
Commissioning
Oil filled through a filter cart, first start at low pressure, settings raised in steps, then recorded with the measured cleanliness.
[06]Applications
Same flow and pressure, different unit.
Duty cycle and environment shape the design.
01
Hydraulic presses
Fast approach, slow high-force pressing: double or power-controlled pump, prefill valve, pressure holding. Units delivered for briquetting, metal-spinning, rotor-pressing and sanitaryware presses.
02
Foundries
Round-the-clock duty in dust: high-capacity filtration, dust-tight tank, strong cooling; fire-resistant HFC water-glycol fluid near molten metal.
03
Steel plants
Continuous casters, pusher furnaces, roll shops: redundant pump groups, accumulator stations, servo-grade cleanliness.
04
Machine tools
Clamping circuits hold pressure for hours on little flow: compact, quiet units with a variable pump or accumulator.
05
Test stands
Cylinder, valve and hose test rigs: stepped, precise pressure control, measurement and logging, strong return filtration.
06
OEM machine builders
Compact units built to the machine’s footprint for bending, punching and woodworking machines, repeated in series, each one function-tested.
Sector detail: steel and iron, presses and metalworking. Cylinders come from the group's own İzmir plant — Hydrocyl™ cylinders and press cylinders — so flow, speed and cushioning are sized with the unit.
[07]Delivered units
HPUs we've shipped.
Continuous-caster HPU fleet
Redundant pump groups, accumulator and filtration stations for a steelworks CCM — FAT-tested together.
Pusher-furnace HPU
24/7 duty beside the furnace line, plate-cooler thermal management.
Foundry moulding-line system
75 kW pump groups and high-capacity filtration for round-the-clock foundry duty.
High-flow flushing HPU
Pickling & flushing of plant piping to servo-grade cleanliness classes.
Roll-shop power unit
Compact HPU with the electrical cabinet integrated on the frame.
Series-built OEM units
Batch production of identical HPUs, each function-tested before shipment.
[08]For your enquiry
What to send for a quote.
Duty cycle, ambient temperature and scope are most often missed — and cause most differences between quotes.
- Actuators: cylinder bore, rod, stroke and number, or motor displacement; required force or torque, and speed.
- Working and maximum pressure; flow, if known.
- Duty cycle: movement sequence and times, pressure-holding time, hours per day.
- Control type (on/off, proportional, servo), valve and mains voltage, motor starting method.
- Site: indoor or outdoor, ambient temperature range, dust, cooling water; fluid and target cleanliness class.
- Space and noise limits; standby pump; the movement needed on power failure.
- Scope: panel and PLC, piping, flushing, commissioning, documents, FAT attendance, quantity.
Missing data? Describe the machine and its job; we do the sizing. Send it via Instant Quote or talk to engineering; for cylinders, try the drawing generator.
[09]Straight answers
HPU questions. Answered plainly.
01 What is a hydraulic power unit?
A hydraulic power unit (HPU), or hydraulic power pack, turns electric motor power into pressurised oil flow for cylinders and hydraulic motors. Reservoir, motor-pump group, valves, filters, cooler and controls sit on one frame.
02 Do you build the electrical panel and PLC software too?
Yes — control panels, PLC programming and SCADA integration are done in-house, designed together with the hydraulic circuit. One supplier is accountable for the whole system.
03 Can you build redundant systems for continuous plants?
Yes — redundant pump groups with accumulator and filtration stations are standard practice for steel-plant and foundry systems that run 24/7; delivered examples include continuous-caster and pusher-furnace units.
04 Is there a factory acceptance test?
Every power unit is run and function-tested at the İzmir works before dispatch. Customer witness testing is welcome, and commissioning on site is done by our own field teams.
05 What documentation ships with an HPU?
Circuit diagram, 3D model and GA drawings, component list, panel schematics and the test record — plus operation & maintenance manuals on request.
06 How do you calculate the motor power of an HPU?
P [kW] = p [bar] × Q [l/min] ÷ (600 × η), where η is the overall pump efficiency, about 0.80–0.90. Example: 200 bar, 50 l/min and η = 0.85 give about 19.6 kW; the next standard motor is 22 kW.
Describe the duty. We'll size the unit.
Flow, pressure, duty cycle and environment — or just the machine it drives. Both work.
Talk to Engineering → Instant Quote