Prestressed jack is a commonly used prestressed tendon tensioning equipment, which is widely used in prestressed construction projects such as highway bridges, railway bridges, hydroelectric dams, and high-rise buildings. Next, we will introduce how it works and how to use it.
Working principle: When tensioning the prestress, the A nozzle enters the oil, the B nozzle returns the oil, the connecting sleeve and the supporting sleeve are connected as one body, and the anchor ring is moved to the right; the tensioning hydraulic cylinder and the plug are combined with the core sleeve to drive The tool anchor wants to move left and stretch. When pressing and anchoring, under the condition of keeping the tensile force stable, the B nozzle enters the oil, the pressing piston, the protective sleeve and the pressing head are combined and moved to the left to force the anchor plug into the anchor ring.
|Model No.||Pull capacity||Pressure||Oil effective area||Stroke||Hollow diameter||Size||Work area||Length||Weigth|
- The NSM-PSJ series of ultra-thin jacks (replacement jacks for bridge bearings) overcome the shortcomings of the old flat-top over-travel piston that jumps away from the jack, while maintaining the low height of the ultra-thin flat-top, there is a piston over-travel limit. Advantages, at the same time, there is an overpressure safety relief valve control system on the jack, and a spherical correction device on the top of the piston, which fully guarantees the safety and reliability during construction. At the same time, the pump station and distribution valve control system can be used to realize a pump station with 24 jacks of this type.
- Suitable for use: the installation and replacement of rubber bearings of new and old bridges, the lifting and transfer of prefabricated beams, the lifting of large components and machinery and equipment in low spaces.
- The NSM-PSJ series of lightweight male jacks adopt a combination of computer analysis and optimization design, especially the advanced technology of pre-stressing treatment of the jack cylinder. Through repeated experiments, many trials have successfully developed the new lightweight jack, which not only Small in size, light in weight, and high in strength, it can be separately tensioned clip group anchor, DM upset anchor and LZM cold cast anchor.
- This series of jacks are light in weight, adapt to complex working conditions, and have excellent performance. The guiding performance has been strengthened and the lifting angle is allowed to be larger. YD series jacking jacks can produce various models and specifications below 2500 tons according to user needs. Suitable for use: component jacking, bridge and pile crane static load test, etc.
Instructions for use: Strictly check the parameters of the jack before use, and avoid overpressure and overload use. Check the oil volume of the oil pump before tensioning, and run the jack empty stroke several times to empty the air in the jack and the oil pipe. Front card jacks are mainly used for initial tensioning and single anchor tensioning, and ordinary through-core jacks are mainly used for overall tensioning of group anchors.
When installing anchors and jacks, for straight prestressed tendons, the line of action of the tensile force and the center line of the tunnel should coincide with each other during the stretching process; for curved prestressed tendons, the line of action of the tensile force should be aligned with the center point of the end of the tunnel. The tangents coincide with each other. When tensioning, the pre-stressed tendons pass through the working anchor, the limit plate, and the jack. The tension sequence of the prestressed tendons should meet the design requirements.