Oil & Gas · Bolting

Hydraulic bolt tensioners MT-BT

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.

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

Series

4.754

kN max load

1.500

bar working

Range

MT-BT topside series

Twelve load cells with 15 mm stroke cover studs from M20 to M150: the size adapts by changing only the adaptor kit (threaded puller, bridge and nut-rotating socket), the load cell stays the same. AISI 4340 alloy steel body, 1,500 bar maximum working pressure.

Model	Bolt range	Max load (kN)	Hydraulic area (mm²)	O.D. (mm)	Weight (kg)*
MT-BT-100	M20 – M24 (3/4" – 1")	339	2.257	84	3,5
MT-BT-200	M27 – M36 (1.1/8" – 1.3/8")	397	2.649	98	4,5
MT-BT-300	M33 – M39 (1.1/4" – 1.1/2")	639	4.259	115	5,9
MT-BT-400	M36 – M42 (1.3/8" – 1.3/4")	721	4.808	128	7,7
MT-BT-500	M42 – M52 (1.5/8" – 2")	942	6.280	145	11,4
MT-BT-600	M48 – M56 (1.7/8" – 2.1/4")	1.354	9.028	165	14,8
MT-BT-700	M56 – M68 (2.1/4" – 2.1/2")	1.651	11.006	180	18,1
MT-BT-800	M64 – M72 (2.1/2" – 2.3/4")	1.978	13.188	198	23,4
MT-BT-900	M72 – M76 (2.3/4" – 3")	2.257	15.045	215	29,3
MT-BT-1000	M80 – M100 (3.1/4" – 4")	3.047	20.312	244	40,3
MT-BT-1100	M100 – M125 (3.3/4" – 4.3/4")	3.768	25.120	280	52,7
MT-BT-1200	M125 – M150 (5" – 5.3/4")	4.754	31.694	325	89,6

MT-BTS — Spring return

The automatic spring return retracts the piston on pressure release, with no manual reset: shorter cycle times on flanges with many studs. Ten dedicated 15 mm-stroke load cells cover studs from M24 to M110; AISI 4340 body, 1,500 bar maximum, interchangeable adaptor kits like the topside range.

Model	Bolt range	Max load (kN)	Hydraulic area (mm²)	O.D. (mm)	Weight (kg)*
MT-BTS-200	M24 – M30 (7/8" – 1.1/4")	330	2.006	98	3,6
MT-BTS-300	M30 – M39 (1.1/4" – 1.1/2")	565	3.768	115	4,6
MT-BTS-400	M36 – M45 (1.3/8" – 1.3/4")	636	4.239	128	7,8
MT-BTS-500	M42 – M48 (1.5/8" – 1.7/8")	845	5.632	145	9,6
MT-BTS-600	M48 – M52 (1.7/8" – 2")	1.354	9.026	165	13,6
MT-BTS-700	M52 – M64 (2" – 2.1/2")	1.530	10.206	180	17,6
MT-BTS-800	M64 – M72 (2.1/2" – 2.3/4")	1.845	12.303	198	20,6
MT-BTS-900	M72 – M76 (2.3/4" – 3")	2.555	17.032	224	26,6
MT-BTS-1000	M80 – M95 (3.1/4" – 3.3/4")	3.134	20.903	248	36,6
MT-BTS-1100	M100 – M110 (4" – 4.1/2")	3.768	25.123	280	48,6

SUB

MT-SST — Subsea

Built entirely from high-strength stainless steel for the corrosive subsea environment: long 25 mm stroke with fluorescent indicator rings, detachable hooks and strap for underwater handling, knurled non-slip surface and optional split nut to minimise diver time. Eight load cells cover studs from M20 to M85, including high pressure-rating flanges (10K).

Model	Bolt range	Max load (kN)	Hydraulic area (mm²)	O.D. (mm)	Weight (kg)*
MT-SST-100	M20 (3/4" – 7/8")	188	1.256	65	2,0
MT-SST-200	M24 – M30 (1" – 1.1/8")	309	2.061	86	4,0
MT-SST-300	M33 – M36 (1.1/4" – 1.3/8")	482	3.215	98	5,5
MT-SST-400	M39 – M42 (1.1/2" – 1.5/8")	706	4.710	117	7,4
MT-SST-500	M45 – M52 (1.3/4" – 2")	1.060	7.065	138	13,5
MT-SST-600	M56 – M64 (2.1/4" – 2.1/2")	1.554	10.362	164	20,7
MT-SST-700	M72 – M76 (2.3/4" – 3")	1.952	13.011	190	23,5
MT-SST-800	M80 – M85 (3.1/4" – 3.1/2")	2.390	15.935	214	31,5

1,500 bar pump units & accessories

Three drive options for the same 1,500 bar working pressure: a two-stage electric unit with 5 m cable remote control, an air-driven unit with 1:350 ratio in a stainless frame, and a 3-litre hand pump. The system is completed by 4-ply high-pressure hoses (1,800 bar working, 4,500 bar burst, -30 to +80 °C), manifolds, fittings and quick couplings: the twin connections on every load cell let you daisy-chain any number of tensioners.

Model	Drive	Max pressure	Flow / reservoir	Weight (kg)
MT-TPE-1500	230 V · 50 Hz · 0,7 kW	1.500 bar	3 / 0,7 l/min · 5 l	42
MT-TPA-1500	Air 5,1 bar · 1:350 · INOX	1.500 bar	— · 5 l	22
MT-TPH-1500	Hand	1.500 bar	— · 3 l	12

Configurator

Which tensioner do you need?

Series, stud size and required preload: we calculate model, kit and working pressure.

How a bolt tensioner works

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.

4,754

kN maximum load at 1,500 bar

±2°

Floating piston: tolerates misalignment with no load loss