Prestressing jack 1. Used for post-tension and pre-tension 2. New technology reduces the cylinder's expansion ratio
YDC series prestressing jacks are the new designed products in our company, are the upgrades of the primary jacks. Features:1. Using the new seals, to synchronous strengthen the seal-ability under great pressure.2. Using special alloy steel with heat treatment process, reducing the cylinder's expansion ratio in the tensioning process, so that the life of seals and sealing performance can be improved about 20%;3. In the tensioning the operating process, jacks is easily damaged under overpressure because of the jack-based pullback cylinder, so we added the overpressure valve on the jacks to pressure production. Meanwhile we improved the original of commonly used structure by wire disc and flanged disc, to make the bearing capacity for oil pressure strengthen, so that enormously reduce the possibility of mechanical damage due to improper operation. In the word, the YDC series feed-through jacks' performance is improved, and widely used in pre-stressing and post-stressing construction. Notice: according to users' requirement, YDC through jack can be configured preventing turn device which can prevent jack from rotating in the process of stressing.
Choosing the specification of prestressing jacks should consider the following tips:1,The stressing of jack should meet the construction requirement, however, consider the impedance loss that produce after filling seal ring and bracing impedance loss between jack and piston, the jack force is about 95% of rated value. If jack need conduct strictly and continuous, the shipping ton of jack should higher than load tonnage, and is calculated per 80% of rated value.2,The diameter of center hole is bigger above 17mm than the diameter of Max. cone hole concentric circle of working anchor.3,For convenient of lectotype, we calculate and make the specification table of lectotype according to the tendon with standard strength of 1860Mpa and diameter of 15.24mm, and the control force of 0.85Fptk.
Stressing jack
