What Makes the RARH Series Different
- Hollow plunger design accepts tie rods, threaded bars or prestressing strands for genuine pull applications.
- Double acting hydraulic return shortens cycle time on repeated lifting and tensioning jobs.
- Aluminum body reduces weight, with the 20T unit starting at only 5.2 kg.
- Composite support ring tolerates up to 10% side load and extends seal life.
- Built-in overload safety valve, integral retaining ring against over-travel, steel base and saddle against loading damage.
- Supplied with carrying handle, quick couplings and dust caps on every model.
Typical Application Scenarios
- Post-tensioning and prestressed concrete work, tensioning multi-strand tendons in bridges, parking structures, sleepers and containment vessels.
- Bearing, bushing and gear extraction on wind turbine gearboxes, rolling mills, mining equipment and ship propulsion shafts.
- Flange alignment and mechanical bolt tensioning on pressure vessels, pipelines and oil & gas installations.
- Structural lifting and lowering of bridge girders, heavy machinery and rail carriages during installation or replacement.
- Anchor testing and pile loading tests in civil engineering, plus tie-back anchorage adjustment in retaining structures.
- Press-fit, straightening and interference-fit assembly in heavy manufacturing and steel fabrication shops.
- Rescue, recovery and emergency lifting where a compact, portable hydraulic tool must work in confined space.
Market Prospects and Why Demand Is Growing
- Global infrastructure renewal (bridge replacement, metro expansion, port upgrades) keeps post-tensioning and structural lifting volumes high.
- Wind energy and offshore maintenance growth creates steady demand for portable hollow cylinders used in bearing, shaft and yaw bearing service.
- Industrial rental fleets are standardizing on aluminum hollow cylinders because they are light to transport and handle multiple job types in one trip.
- The shift toward electric and remote-controlled hydraulic pumps pairs naturally with double acting cylinders, enabling automated, repeatable pulling cycles with less operator exposure.
- Galaxy Machinery continues to extend the RARH platform, offering 20T–150T today, with longer stroke and higher tonnage variants under development.
Safe Operation and Usage Precautions
- Pair the cylinder with a hydraulic pump rated for at least the system working pressure, and never exceed the capacity stamped on the label.
- Keep the load concentric. The support ring tolerates 10% side load, but offset or angled loading will score the plunger and destroy seals.
- Do not exceed maximum stroke. The integral retaining ring is a safety device, not a normal travel stop.
- Use clean hydraulic oil (typically ISO VG 32 or 46) and keep couplings capped with dust plugs. Contamination is the leading cause of premature seal failure.
- On pull jobs, fit a threaded pull rod through the center bore sized to the listed inside diameter, never exceeding the rod material yield.
- Once positioning is complete, support the load mechanically. Do not leave a cylinder holding load unattended.
- Recertify critical lifting cylinders on a test bench at least once a year, and verify the built-in safety valve setting.
- Store cylinders fully retracted, in a dry environment, with ports capped.
Wear safety glasses, gloves and head protection, and keep all body parts clear of the load path during pressure buildup.
The RARH Series is available ex stock with full catalog data, dimension drawings and CE documentation on request.
