Scope
This guideline identifies the methods to be used for troubleshooting proving operations using tank provers.
TANK PROVER TROUBLESHOOTING FOR OPERATIONS
Frequency As indicated below
Procedure
| Problem | Location & Probable Cause | Test/Inspection | Corrective Action |
| Poor Repeatability | —– Prover —– | ||
| Inconsistent drain down time. |
Measure drain-down time | Follow drain-down time on calibration certificate. |
|
| Drain valve leaks. | a) Fill prover to capacity.
b) Read upper scale and letstand 15 minutes. c) Then read scale again to |
Repair valve w/o removing. Replace valve and recalibrate. |
|
| Unstable power. | Try rocking by applying amodest force. | Level prover and make secure. |
|
| Unsatisfactory fill condition |
Fill pipe must always drain completely or always retain the same amount of fluid before and after each run. |
Secure fill pipe position. Provide vent in fill pipe. |
|
| Unstable flow rate. | Monitor flow rate. | a) Secure flow rate control valve. b) Stabilize back |
|
| Vaporization | Lower flow rate. | Changes fill procedure. | |
| —– Meter —– | |||
| Bearing wear. | Dismantle and inspect. | Repair or replace as required. |
|
| Counter does not repeat. |
Remove counter and hold input shaft firmly while resetting, to see if it resets to zero each time. |
a) Repair or replace as required. b) Check gear backlash |
|
| Meter cavitation | Apply excessive back pressure for a brief time. |
Adjust back-pressure according to requirements.
|
|
| Meter calibrator. | Isolate and test temperature mechanism. |
Repair or replace as required. |