Applications
Engineering-grade PLC multi-point synchronous lifting solutions, high-tonnage double-acting cylinders (100–1000 t), and mechanical lock-nut actuators for bridge bearing replacement and structural elevation.
Hydraulic System Configurator
Mode A · Bridge elevation schematic
Calculated system output
Peak force / point
— kN
—
Cylinder bore
—
Ton class
—
Recommended jack type
—
PLC HPU specification
—
—
Structural parameters
Hydraulic & safety constraints
Engineering consultation and multi-point jacking load logic provided by EKXIA.
Custom OEM capability
Function-defined cylinder families — bore, stroke, mount, and lock-nut geometry engineered from your lift plan and structural drawings.
Single or double-acting jacks with integral mechanical load-holding nuts for long-duration structural support without hydraulic pressure. 50–1000 t class at up to 700 bar — ideal when personnel work beneath a lifted deck or power isolation is required overnight during bearing replacement.
100–1000 t double-acting heavy cylinders with hydraulic retraction for fast return between lift cycles. Safety tilt saddles compensate up to ~5° bearing seat misalignment during bridge jacking, reducing side load on rods when pier caps are out-of-level.
Extremely low collapsed height — often under 80 mm — for initial gap entry at tight bearing pockets before swapping to full-stroke main lift cylinders. Used in staged lift sequences on highway and rail bridge maintenance contracts.
Engineering guidance
Indicative configurations for civil and heavy-lift contractors — confirm with structural analysis, lift plan review, and local code requirements.
| Application scenario | Engineering challenge | Recommended hydraulic configuration | Safety margin |
|---|---|---|---|
| Bridge bearing replacement (highway / rail) | Uneven pier stiffness, limited under-deck clearance, multi-day holds with traffic control. Frozen or corroded bearings add spike loads during break-free. | 8–16 point PLC synchronous system · CLL lock-nut jacks on primary points · RLP pancake for initial gap · CLRG double-acting for main stroke · 700 bar HPU with dual pumps and emergency dump | 1.25–1.40× on total deck weight |
| Building elevation & positioning | Long stroke with level tolerance across irregular foundations; sustained hold while shims or new plinths are installed. | 4–8 point sync · CLRG double-acting with tilt saddles · lock-nut backup on critical corners · stroke 200–300 mm · position transducers feeding PLC closed-loop | 1.20–1.30× structural weight |
| Heavy offshore module weighing & jacking | High center of gravity, dynamic wind load, need for verified weight before load-out; uneven skid beam contact. | 12–16 point load-cell integrated jacks · CLRG 500–1000 t class · 350–700 bar depending on bore limit · synchronized E-stop and hard mechanical stops on each point | 1.30–1.50× including dynamic load case |
System architecture
Beyond cylinder bore: control topology, hold logic, and field serviceability define project success on bridge contracts.
Bridge decks and girders are indeterminate structures — uneven lift at one corner induces torsion, bearing bind, and grout crushing at adjacent supports. PLC-controlled multi-point systems maintain position differential within ±1 mm while sharing total load across 4–16 jacks, keeping elastomeric bearings parallel during swap-out.
Lock-nut (mechanical load-holding) cylinders secure the structure after hydraulic pressure is released — essential for overnight holds, personnel under-deck access, or power loss during multi-day bearing projects. Double-acting cylinders with hydraulic retraction suit continuous cycling where the load stays on oil and pilot checks maintain position.
Field practice typically applies 1.15–1.30× on total structural weight to cover uneven stiffness, frozen bearings, and wind during lift. Heavily skewed or damaged spans may warrant 1.40–1.50× until a structural engineer confirms as-built reactions. The calculator defaults to 1.25×.
Total flow ≈ (cylinder area × lift speed × number of points) / 10,000 when area is in cm² and speed in mm/min. Bridge jacking often runs 3–10 mm/min for control — size the HPU for synchronous extend at target speed plus 20–30% margin for valve leakage and cold oil viscosity.
OEM & customization
Lift plan summary, number of points, total structural weight, stroke, working pressure, lock-nut requirement, and project timeline.
Heavy structure lifting
HydraulicsMfg builds lock-nut, double-acting, and pancake cylinders plus HPU/manifold packages matched to your PLC sync topology and bridge maintenance schedule.