Bolt Tensioning & Hydraulic Power
High-pressure oil to tension bolts & drive tools.
What is Bolt Tensioning & Hydraulic Power?
Bolt tensioning uses hydraulic pressure to stretch large bolts to exact preload — far more accurate than torque wrenches. Hydraulic power packs provide high-pressure oil for tensioners, presses, jacks and hydraulic tools.
Critical for flange connections in pressure vessels, wind turbines, bridges and heavy machinery. Under-tensioned bolts leak or loosen; over-tensioned bolts yield or break.
Key terms: bolt tensioner (hydraulic tool that stretches bolt), hydraulic power pack (pressure source), preload (target bolt force).
Manual vs Electric vs Air-Driven
Drive methods differ sharply in pressure limit, explosion safety, and automation.
| Drive Method | Pressure Limit | Explosion-Proof | Features |
|---|---|---|---|
| Manual pump | ~100 MPa | ✓ (no electricity) | Cheap / labor-intensive / no automation |
| Electric pump | ~300 MPa | Needs Ex motor | Automated / needs power / heat |
| Air-driven pump | ~600 MPa [TBC] | ✓ (pneumatic) | Safe / auto hold / no power |
For bolt tensioning, air-driven hydraulic pumps = portable + safe + precise.
SUNCENTER Equipment for This Process
Hydraulic Power Pack
Portable high-pressure oil source.
Air-Driven Hydraulic Pump
Compact, no electricity, for field use.
Bolt Tensioner
Hydraulic tool for exact preload.
Process Flow Diagram
Flow subject to technical-dept. confirmation
Connect
Tensioner onto bolt, hose to pump.
Pressurize
Hydraulic oil stretches bolt.
Tension
Reach target preload.
Lock
Turn nut down, release pressure.
Relief
Depressurize, disconnect.
Typical Parameters
Values per product manual — for reference only.
| Workpiece | Test / Working Pressure | Recommended Model |
|---|---|---|
| M20-M36 bolts | 70-150MPa | Air-driven pump |
| M36-M64 bolts | 150-250MPa | Hydraulic power pack |
| Custom flanges | Per spec [TBC] | Custom system |
Further Reading
Blog system under construction — titles below are planned.
- Bolt tensioning vs torquing: why preload mattersTBC
- Air-driven vs electric hydraulic pump for field useTBC
- Common bolt tensioner faults & maintenanceTBC
Need Bolt Tensioning & Hydraulic Power equipment?
Tell us your working conditions and target pressure — our engineers recommend the right model.