FLAT JACKS – LIFTING BAGS
& LOW HEIGHT CYLINDERS
HYDRAULIC JACKS • HYDRAULIC CYLINDERS • PUMPS • SYNCHRONOUS LIFTING SYSTEMS
RENTALS • SALES • SERVICE
Freyssi Flat Jacks: Small Tools with Big Impact in Structural Engineering
In the world of construction, infrastructure maintenance, and structural engineering, few devices combine compact design with sheer power quite like the Freyssi Flat Jack. Distributed in the United States by WB Equipment, these innovative tools play an essential role in projects ranging from bridge rehabilitation to the stabilization of historic buildings. Slim enough to fit into tight spaces yet strong enough to apply immense loads, Freyssi Flat Jacks have earned a reputation as indispensable problem-solvers across multiple industries.
Freyssi Flat Jack
Freyssi
Low Height Jacks
Enerpac
Air Lifting Bags
Simplex
Ultra Flat Cylinder
Enerpac
Common Applications
Because of their versatility, Freyssi Flat Jacks are used in many different scenarios, including:
Preloading and prestressing beams, joints, and other structural elements.
Transferring loads in bridge bearings during maintenance or replacement.
Lifting or realigning structures in confined work zones.
Applying controlled forces in laboratory tests and structural mock-ups.
Repairing and stabilizing concrete in tunnels, dams, and other large infrastructure.
Typically, the jack is inserted into the space between two structural members. Hydraulic pressure is applied gradually, ensuring even distribution of force. Once the desired adjustment is reached, steel plates are inserted as permanent supports before depressurizing the jack.
Essential Accessories
For optimal performance, Freyssi Flat Jacks are typically used with:
Hydraulic pumps (hand-operated or powered) to generate pressure.
Pressure gauges for precise monitoring.
Steel shims or packers for locking loads in place.
Flexible hoses to allow use in hard-to-reach areas.
Protective housings when long-term or embedded installation is required.
WB Equipment supplies these accessories as part of a complete system, ensuring contractors have everything needed for reliable operation.
Who Uses Them in the USA?
Across the United States, Freyssi Flat Jacks serve a variety of industries:
Civil Construction – for bridge bearing replacement, column alignment, and wall stabilization.
Transportation Infrastructure – including rail and highway systems requiring support adjustments.
Power and Energy – from hydroelectric dams to nuclear facilities, where structural integrity is critical.
Mining and Tunneling – for controlled lifting and support in confined underground spaces.
Marine and Offshore – in foundation maintenance and subsea structures.
Historical Preservation – to carefully stabilize and reposition fragile architectural elements.
Advantages and Interesting Facts
The concept of the Flat Jack was pioneered by Eugène Freyssinet, a trailblazer in prestressed concrete technology.
Their thin profile allows them to be embedded directly into concrete and permanently grouted into place.
They provide highly accurate pressure control, making them safe for sensitive applications.
Multiple jacks can be operated simultaneously for balanced load distribution.
Custom sizes are available, and WB Equipment often supplies specialized versions for unique engineering challenges.
Flat Jack
Freyssi
Flat Jack
Freyssi
Flat Jack
Freyssi
Flat Jack
Freyssi
Enerpac Low-Height Hydraulic Cylinders:
Maximum Power in Minimal Space
What They Are
Enerpac’s line of low-profile hydraulic cylinders—also known as hydraulic pancake jacks—are designed for jobs requiring high force in extremely tight vertical clearances. Models include:
CUSP Series: Single-acting, spring return
CULP Series: Lock nut load-holding design
LPL Series: Extra-low profile for extreme constraints
Key Specs:
Rated for 10,000 psi (700 bar)
Feature Nitrocarburized coating for corrosion protection
Comply with ASME B30.1 standards (except BRD-RD-Series)
Where and How They’re Used
These cylinders are ideal for:
Bridge bearing replacements
Steel mill maintenance
Heavy machinery positioning
Power plant infrastructure projects
Their compact design makes them invaluable in applications where standard jacks simply won’t fit.
Accessories Needed
Hydraulic pump (manual, electric, or air-powered)
High-pressure hoses and couplers
Pressure relief valves
Synchronization controls (for multi-jack lifts)
Industries in the U.S.
Construction and civil engineering
Energy sector (nuclear, hydro, wind)
Shipbuilding and aerospace
Heavy equipment maintenance
Interesting Fact:
Despite their small height (as little as 1.5 inches), Enerpac flat cylinders can lift over 100 tons, making them true powerhouses in tight quarters.
RSM Low Height
Enerpac
LPL Low Height
Enerpac
CUSP Ultra Flat
Enerpac
CULP Flat Cylinder
Enerpac
Common Applications
Because of their versatility, Freyssi Flat Jacks are used in many different scenarios, including:
Preloading and prestressing beams, joints, and other structural elements.
Transferring loads in bridge bearings during maintenance or replacement.
Lifting or realigning structures in confined work zones.
Applying controlled forces in laboratory tests and structural mock-ups.
Repairing and stabilizing concrete in tunnels, dams, and other large infrastructure.
Typically, the jack is inserted into the space between two structural members. Hydraulic pressure is applied gradually, ensuring even distribution of force. Once the desired adjustment is reached, steel plates are inserted as permanent supports before depressurizing the jack.
Essential Accessories
For optimal performance, Freyssi Flat Jacks are typically used with:
Hydraulic pumps (hand-operated or powered) to generate pressure.
Pressure gauges for precise monitoring.
Steel shims or packers for locking loads in place.
Flexible hoses to allow use in hard-to-reach areas.
Protective housings when long-term or embedded installation is required.
WB Equipment supplies these accessories as part of a complete system, ensuring contractors have everything needed for reliable operation.
Who Uses Them in the USA?
Across the United States, Freyssi Flat Jacks serve a variety of industries:
Civil Construction – for bridge bearing replacement, column alignment, and wall stabilization.
Transportation Infrastructure – including rail and highway systems requiring support adjustments.
Power and Energy – from hydroelectric dams to nuclear facilities, where structural integrity is critical.
Mining and Tunneling – for controlled lifting and support in confined underground spaces.
Marine and Offshore – in foundation maintenance and subsea structures.
Historical Preservation – to carefully stabilize and reposition fragile architectural elements.
Advantages and Interesting Facts
The concept of the Flat Jack was pioneered by Eugène Freyssinet, a trailblazer in prestressed concrete technology.
Their thin profile allows them to be embedded directly into concrete and permanently grouted into place.
They provide highly accurate pressure control, making them safe for sensitive applications.
Multiple jacks can be operated simultaneously for balanced load distribution.
Custom sizes are available, and WB Equipment often supplies specialized versions for unique engineering challenges.
Lifting Bags
Simplex
Lifting Bags
Simplex
Lifting Bags
Simplex
Lifting Bags
Simplex
Closing Thoughts
Freyssi Flat Jacks may not look imposing at first glance, but their ability to deliver precision force in tight spaces makes them vital across countless structural applications. With the support of WB Equipment, industries in the U.S. have access to these versatile hydraulic tools along with the pumps, gauges, and accessories needed to put them to work. Whether stabilizing a bridge, adjusting a tunnel lining, or preserving a landmark building, Freyssi Flat Jacks prove that sometimes the most compact tools make the biggest difference.