Tension Jacking Cylinder Calibration Requirements

Prestressed jacks used in engineering should undergo testing and inspection prior to use to prevent malfunctions during operation, which could affect normal work. The calibration period for hydraulic jacks used in prestressing should not exceed six months. Recalibration of the hydraulic jacks used in prestressing is required under any of the following circumstances:

(1) Before the first use of the new jack.

(2) The pressure gauge needle did not return to zero after replacing it with a new gauge.

(3) Jacks, pressure gauges, and oil lines have been replaced or repaired.

Several broken strands of prestressed steel during tensioning or significant errors in the tensioning elongation value occurred.

(5) After three months of non-use and before reactivation.

(6) When the fuel gauge is subjected to significant impacts, such as from drops or collisions.