Hydraulic Calibration is carried out by Positive Displacement Provers. The operating principle is comparison of volumetric flow registered by the flowmeter under test and the corresponding volume displaced by a elastometer sphere displaced through the calibrated section of the prover loop, duly corrected for the operating temperature and pressure in the loop and the flowmeter under test.
 

50mm Bi-Directional Positive Displacement Prover

      The 500mm prover is a Bi-Directional Positive Displacement Prover, designed and operated according to API 2531/ MOPMS.
The proving system consists of a Pump house, Metering runs and the Prover loop. The pumping station consists of 5 centrifugal pumps with a total power of 250 KW and a capacity of 3200 m3/hr. The metering section consists of 2 parallel metering runs designed for small and large flowmeters respectively. The run includes flow conditioners, sliding joints, block and bleed valves etc.

The prover loop consists of a precision pre-calibrated section, sphere detectors at the begining and end of the calibrated section, hydraulically operated sphere launchers and receivers and a 4-way valve for reversing the flow through the loop. The metering runs and prover loop are connected in series. During each calibration volume registered by the flowmeter is compared with the calibrated volume of the prover barrel, represented by the volume swept by the sphere while passing through the calibrated section. The entry and exit of the sphere from the calibrated section is signaled by the detectors. The prover has a certified repeatability of 0.003%.

100mm Uni-Directional Positive Displacement Prover

      The 100mm Uni-Directional Prover works on the same principle as 500mm prover. This prover can handle flows upto 120 m3/hr and has a certified repeatability of 0.00503%.
 

Supplementary Transfer Loop

A supplementary transfer loop is available on the 500mm prover. This supplementary loop is in accordance with API 2534 and has a flow capacity of 3200m3/hr.