Hydraulic bolt tensioner MT series

single-stage

Tensioning applies a pure axial pull to the stud: no torsion, no friction under the nut, accurate and repeatable preload on every bolt of the flange. The range covers studs from M20 to M150 with loads up to 4,754 kN at 1,500 bar, in three series: MT-BT topside, MT-BTS spring return and stainless-steel MT-SST subsea.
The nut-rotating socket drops over the nut, bridge and load cell rest on the flange and the threaded puller screws onto the stud protrusion, engaging at least one diameter. Hydraulic pressure stretches the bolt within its elastic range; the nut is run down at zero torque and, once pressure is released, the preload stays in the stud. The twin manifold connections on every load cell allow all flange bolts to be tightened simultaneously, with 100% or 50% tool coverage.
The integral stroke indicator with red over-stroke line, the internal pressure-relief safety in the event of over-stroke and the floating piston that tolerates 2° of misalignment without load loss make the cycle safe and repeatable. The applied load is calculated from the required residual preload times the load relaxation factor (≥1.1), never exceeding 95% of the stud yield strength.

• Pure axial load: zero torsion on the stud
• Studs from M20 to M150 (3/4" – 5.3/4")
• Multi-tensioning: simultaneous 100%-coverage tightening

Tell us stud diameter and material, required preload and flange geometry: we will propose series, size, adaptor kits and pump unit.