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Calibration Method for Calibrated Cylinder Used in Water Jacket Hydrostatic Test

1. Testing Operation Requirements

1.1 Laboratory environment temperature should be constant, keep stable for the water temperature and environment temperature balance in the water jacket, and water temperature inside the water jacket basically consistent then could start the testing.

1.2 Before testing to verify the sealing performance of test device. Operation procedure as follows: after being sealed for the water jacket, then connect the water jacket with the water measurement device,the electronic balance data should be stable for at least 5 min.

1.3 After put the calibration bottle into the water jacket, exhaust out the air totally for the special water jacket and connection pipeline.

1.4 The calibration electronic scale should be reset before testing, and should confirm there is stable values without drift, the data should be stable at least 5 min.

1.5 Start calibration, the pressurization rate should meet the requirements.

1.6 During testing,the pressure should be kept at least 30 S without dropping down, indicating value of electronic scale should be stable.

1.7 After holding time, release pressure slowly to zero; Display date shown "0" of the electronic scale and the data should be stable not less than 1 min.

1.8 During the holding time,sealing inspection is required of the device if the test pressure or scale values is not stable. After troubleshooting could be tested again.

1.9 The maximum test pressure shall not greater than the pressure of the steel tag on standard bottles or the maximum pressure shown on the last calibration certificate; The calibration pressure series shall be not less than three degrees or confirmed together with the vendor.

1.10 It should be testing from low pressure to high pressure, each pressure value should be testing at least 5 times to record the set pressure,total volumetric expansion value and permanent volumetric expansion value; Each test the permanent volumetric expansion value should be "0", and the relative deviation of each total volumetric expansion value should be no more than ±0.3%.

1.11 Shall not be used as the standard bottles if the permanent volumetric expansion values is not "0".

2, Test records, reports, and data acquisition

2.1 The standard bottle should have the calibration records included below:

A) Calibration date

B) Calibration pressure;

C) Calibration temperature (environment temperature, water temperature inside the water jacket ,water temperature inside the bottle);

D) The holding time;

E) Total volumetric expansion value;

F) Permanent volumetric expansion value;

G) Abnormal performance for the bottles;

H) Calibration operator signature.

2.2 The total volumetric expansion values in the Calibration report shall be taken the average value of several times testing as standards, and the value should not be less than 0.9999.

2.3 Paste the waterproof label with standard cylinder in the upper of the qualified standard bottles.

2.4 The results of the data shall be shown below as standards:

A) Calibration pressure in the unit "MPa" to retain two decimal places,and keep to bits.

B) The total volumetric expansion values all keep a decimal places according to the rounding rules, but when second decimal places is "5"and with odd in left of the decimal, round up exact number;     if is even, then round down the nearest number.