SSV PG1
Bolt Tensioner for recessed bolt threads
Cost-reducing - Powerful - Reusable
Bolt Tensioners can be removed from the bolt connection after pre-tensioning:
in comparison, Hydraulic Nuts remain on the bolt or component connection.
The distinguishing feature of the Bolt Tensioner of product group 1 is that the cylinder-piston-set is placed over a recessed bolt thread and that, then, a tension nut is screwed down to the stop face of the piston.
Basic position
The tensioning force is achieved and the Main nut can be turned down to contact the flange. When releasing the oil pressure, the desired tensioning force remains in the bolt connection. After removing the SSV, you may use the equipment for tensioning other bolts.
Piston
Bolt to tension
Thread Sleeve
Cylinder
Positioning of the Main nut
The tensioning force is achieved and the Main nut can be turned down to contact the flange. When releasing the oil pressure, the desired tensioning force remains in the bolt connection. After removing the SSV, you may use the equipment for tensioning other bolts.
Main Nut
Positioning of the Main nut
The tensioning force is achieved and the Main nut can be turned down to contact the flange. When releasing the oil pressure, the desired tensioning force remains in the bolt connection. After removing the SSV, you may use the equipment for tensioning other bolts.
Advantages
Bolt Tensioners
„Crossover-tightening“ of several bolts at several points is no longer necessary, since SCHAAF SSV and HM offer the
possibility of tightening all the bolt connections simultaneously with exactly the same tensioning force. This also applies
when increasing the tensioning force.
As opposed to thermal screw starting procedures, SCHAAF SSV and HM make it possible to eliminate different gaps
between individual components. Each bolt can be tensioned with exactly the same force and not over the same distance!
SCHAAF SSV and HM make it possible to apply a residual tensioning force by means of test force stress application in
order to determine if any settling of the screw may occur, and if so, to eliminate it.
With a compact unit and the ability to interchange the component parts relating to the size of the bolt, SCHAAF SSV can also be used for other thread sizes.
SSV and HM will dramatically save time required for tensioning applications. This effect increases for higher tensioning forces, larger bolt thread diameters and also the installation of several SCHAAF SSV or HM. Time savings up to 99% are possible! It is no longer necessary to apply large torque by hand. There is a number of handling features available, designed to make work easier with SCHAAF Bolt Tensioners and Hydraulic Nuts, especially when it comes to large dimensions.
Features SSV PG1
- single-stage
- tension nut
- for recessed bolt threads
- SSV simple to place, thus short set-up times
- short spindle path of nut due to recessed tension thread
- easy handling because of low weight of tension nut when screwing on and off
More Bolt Tensioners
Bolt Tensioner for recessed bolt threads
Bolt Tensioner for continuous bolt threads
Bolt Tensioner with immersion nut (puller)
Bolt Tensioner for recessed bolt threads with tension thread directly in the piston
Bolt Tensioner for recessed bolt threads with tension thread directly in the piston
Bolt Tensioner with lengthened bolt for continuous or recessed bolt threads
Bolt Tensioner with a multistage cylinder-piston-set
Bolt Tensioner as ring segment for simultaneous pressurisation of all SSV
Versions
In addition to a number of standardized Bolt Tensioners and Hydraulic Nuts, SCHAAF has already delivered thousands of customized axial Bolt Tensioners. The Design on Demand CAD system allows to realize customer solutions very
quickly. Based on axial pre-tensioning technics, a number of patented, specialized solutions have been developed during the last years. Bolt Tensioners, Hydraulic Nuts and ExpaTen, as well as the A-Loc and EcoRolls, both developed
especially for rolling mills, all represent a 100% system solution with SCHAAF’s accessories such as high-pressure hoses and high-pressure generators.
Areas of Application
The application areas for Bolt Tensioners and Hydraulic Nuts are unlimited. The great amount of user solutions have resulted in a great number of various designs. For this reason it is not always possible to classify all Bolt Tensioners and Hydraulic Nuts into a specific product group. For example, the tensioning force can be transmitted by a thread or a bayonet. Please contact us for your special application.
Quality Assurance
All Bolt Tensioning Tools and Hydraulic Nuts are checked for material quality, dimensional accuracy, proper operation, and pressure resistance. They are subject to quality assurance measures during order execution and delivered with detailed documentation.
Services
SSV and HM are, of course, delivered packaged, ready for installation and operation.
SCHAAF SSV and HM are user-friendly, reliable and are manufactured in accordance with the highest level of technical know-how. Our highly-motivated
staff will be pleased to train your personnel, in situ or at our works, in the general handling of high-pressure equipment.
Related Accessories
Fully assembled and ready for immediate use Hand lever pump up to 4,000 bar hydraulic pressure.
MEDIA AND MORE
Frequently asked questions about the Bolt Tensioner SSV PG1
A Bolt Tensioner is a hydraulic tool that elongates bolts axially in a controlled manner to generate a defined pre-tensioning force. Unlike torque wrenching methods, the bolt is not subjected to high torque. The SCHAAF SSV PG1 Bolt Tensioner is removed after pre-tensioning and can be reused.
During hydraulic bolt tensioning, a defined hydraulic axial force elongates the bolt in a controlled manner. This allows the Main Nut to be turned down to contact the flange without applying high torque. The hydraulic pressure is then released, while the generated pre-tensioning force remains in the bolt connection. This method enables precise and largely torsion-free generation of the pre-tensioning force.
The Bolt Tensioner is placed onto the bolt and attached to the tension thread. Hydraulic pressure then generates an axial force that elastically elongates the bolt. During this process, the Main Nut can be turned down to contact the flange with almost no force. After releasing the hydraulic pressure, the desired pre-tensioning force remains in the bolt connection.
A Bolt Tensioner is recommended whenever high pre-tensioning forces, high repeatability or uniform loading of several bolts are required. Particularly for large flange connections, hydraulic bolt tensioning offers significant advantages compared with torque wrenching methods.
The SSV PG1 enables precise and reproducible pre-tensioning of bolts with recessed tension threads. It reduces the influence of friction, shortens assembly times and can be reused after operation. Several bolts can be tensioned hydraulically at the same time, resulting in uniform load distribution.
Yes. The SCHAAF SSV PG1 Bolt Tensioner is specifically designed for applications in which flange connections have to be assembled with an exactly defined pre-tensioning force. Uniform hydraulic bolt tensioning can improve leak-tightness and operational safety.
Yes. The SSV PG1 is suitable for highly loaded bolt connections in shipbuilding, for example in drive systems, pipelines or large flange connections. Wherever high pre-tensioning forces are required, hydraulic bolt tensioning offers significant advantages.
Yes. In power plants and energy facilities, Bolt Tensioners are used to assemble large bolt connections safely, quickly and with a defined pre-tensioning force. Hydraulic bolt tensioning supports high process reliability and reproducible assembly results.
Yes. Large bolt connections on wind turbines often require exactly defined pre-tensioning forces. The SCHAAF SSV PG1 Bolt Tensioner supports uniform pre-tensioning and is therefore suitable for numerous applications in wind energy.
The SSV PG1 is designed for bolts with a recessed tension thread. To use the Bolt Tensioner, sufficient thread overhang above the Main Nut is required for the tension nut.
No. The number of Bolt Tensioners required depends on the respective application. Depending on the bolt connection, several bolts can be tensioned hydraulically either simultaneously or one after the other.
Yes. Several Bolt Tensioners can be hydraulically connected to each other. This allows several bolts to be tensioned simultaneously with the same pre-tensioning force, resulting in particularly uniform tensioning of large flange connections.
No. During hydraulic tensioning, the bolt is elongated in a controlled manner within its elastic range. When correctly designed and applied, no damage to the bolt occurs.
Yes. The remaining pre-tensioning force can be checked by reapplying hydraulic pressure. This allows settling effects to be identified and compensated for if necessary.
Yes. After pre-tensioning, the SSV PG1 is removed from the bolt. It can therefore be reused for further bolt connections.
The selection of the appropriate Bolt Tensioner requires information including the bolt diameter, thread, material, required pre-tensioning force and available installation space. The installation position and the number of bolts to be tensioned are also important design criteria.
The selection depends on the bolt geometry, the required pre-tensioning force and the available installation space. Based on this technical data, the appropriate version of the SCHAAF Bolt Tensioner can be determined.
The SSV PG1 is operated with a suitable hydraulic high-pressure pump. Depending on the application, Hand Lever Pumps or electric and air driven High-pressure Units can be used.
A Bolt Tensioner is used only during assembly and is removed afterwards. A Hydraulic Nut remains permanently on the bolt connection and can later be used again for releasing or pre-tensioning the connection.
Yes. The SSV PG1 is designed with compact dimensions. However, whether it is suitable for a specific installation situation depends on the available axial and radial installation space. These dimensions are taken into account during the design process.
Hydraulic bolt tensioning enables high accuracy when pre-tensioning large bolt connections. At the same time, assembly times are reduced, pre-tensioning forces are distributed uniformly and the influence of friction is significantly reduced. This method is therefore used in areas including general mechanical engineering, plant construction, shipbuilding, powerplant technology and wind energy.
SCHAAF GmbH & Co. KG develops and manufactures hydraulic bolt tensioning tools for the controlled assembly of large bolted connections. The product range includes various standard series as well as custom solutions for a wide variety of bolt sizes, preload forces, and installation conditions.
SCHAAF manufactures hydraulic bolt tensioners for the largely torsion-free assembly of bolted connections. This process applies the required preload force axially to the bolt, rather than generating it through high tightening torque. As a result, the bolt does not undergo significant twisting during tensioning, and the influence of thread and bearing surface friction is significantly reduced.
