Hydraulic Power Unit for Prestressing: A Breakthrough in Modern Construction and Precast Concrete Production

Modern architecture and industrial construction require building faster, higher, and with reduced material consumption. Traditional heavy monolithic structures are increasingly being replaced by prestressed concrete technology. This method enables large spans without intermediate columns, reduces overall structural weight, and saves up to 30% of steel and concrete. The key component making this engineering solution possible is the hydraulic power unit for prestressing. It serves as the high-tech “heart” of the production line, supplying energy to hydraulic mechanisms and ensuring exceptional strength of future structural elements.

Purpose of Prestressing Technology and Operating Principle of Hydraulic Equipment

Conventional concrete performs well under compression but is vulnerable to tensile stresses. To prevent floor slabs or bridge girders from sagging and cracking under load, steel strands are prestressed prior to concrete casting. After the concrete gains the required strength, the strands are released, transferring compressive force to the structure and significantly increasing rigidity and deformation resistance.

To ensure successful prestressing, stable and precisely controlled high pressure is required. The hydraulic pumping station supplies filtered hydraulic oil at pressures up to 420 bar, driving heavy-duty hydraulic jacks, smooth-release cylinders, and steel cutting tools. The standard configuration includes a radial piston pump mounted on the motor flange, a reliable drive unit (three-phase, gasoline, or pneumatic motor options), a pressure gauge, and a safety valve system. Operation is controlled via a durable hydraulic directional control valve ensuring accurate load regulation.

Integration into Production Processes and Practical Applications

The performance of the hydraulic power unit directly affects construction speed and plant profitability. Equipment is selected according to production scale and operational requirements.

For localized tasks on construction sites, the portable PAUL NG15 unit is used. Despite its compact size, it delivers up to 420 bar operating pressure, allowing efficient prestressing operations outside the factory environment.

At modern precast plants producing hollow core slabs, piles, and beams, higher-capacity units are required.
Models such as the PAUL NG50 integrate seamlessly with all proprietary jacks and cutting systems.
For maximum throughput on long casting beds, the powerful PAUL NG100 (with 3.0 kW, 5.5 kW, or 7.5 kW motors)
is the industry standard. This unit can simultaneously supply up to three four-hose hydraulic jacks, significantly accelerating the casting process. For final controlled strand release of hollow core slabs, specialized pumping stations such as NG130 or NG200 are used in combination with single-acting cylinders.

Advantages of PAUL Hydraulic Solutions for the Construction Industry

Implementation of advanced hydraulic systems from the German brand PAUL provides precast manufacturers and contractors with measurable commercial benefits:

• Scalable productivity – Powering up to three high-capacity jacks from a single unit (NG100) increases daily output without expanding equipment inventory.
• Exceptional prestressing accuracy – Adjustable safety valves and precision pressure gauges ensure correct wedge seating and strict compliance with calculated loads, minimizing production defects.
• Operational flexibility – A wide range of drive options (three-phase electric, gasoline, pneumatic) enables efficient use both in factory environments and on construction sites.
• High durability and safety – Integrated return-line filters maintain hydraulic oil cleanliness, while automatic circuit breakers protect the motor from overheating under extreme loads, minimizing downtime risks.

Order Reliable Equipment for Production Modernization

A professional hydraulic power unit for prestressing from PAUL is the foundation of profitability for any precast concrete plant. By investing in reliable prestressing technology, you gain the ability to produce premium-quality products
that meet the strict requirements of modern construction projects.

TDM Engineering Oy supplies industrial hydraulic power units with various performance capacities. Contact us today for expert engineering consultation, accurate configuration selection for your production line,
and direct order placement.

FAQ – Frequently Asked Questions

1 What is the function of a hydraulic power unit in precast production?
It supplies working pressure to hydraulic tensioning jacks, strand release cylinders, and cutting tools required for prestressed concrete production.

2 What operating pressure do PAUL stations provide?
The equipment maintains stable operating pressure up to 420 bar, ensuring precise strand tensioning.

3 Are hydraulic units suitable for on-site operation?
Yes. Portable and compact models such as PAUL NG15 are specifically designed for field applications.

4 How many jacks can be connected to one unit?
Industrial units of the PAUL NG100 series can simultaneously operate up to three four-hose hydraulic jacks.

5 What motor types are available?
Standard configuration includes three-phase electric motors (3.0–7.5 kW), with optional gasoline engines, pneumatic drives, or AC motor variants.