A.3 Test procedure for LPG dispensers

A typical installation, in which a full-stroke type pipe prover is used for verifying an LPG dispenser, is shown in Figure A.13. The basic test procedure is as follows:

Locate the pipe prover horizontally and close to the dispenser (to make the pipework as short as possible).
Connect the outlet nozzle of the dispenser to the inlet of the twin-type 3-way valve connected to the pipe prover.
Position the 3-way valve to initiate the flow. Purge gas adequately and conduct preliminary runs. Check that no air bubbles are present by means of a sight glass.
Locate the displacer at the starting position and reset the indication of the dispenser.
Start the cylindrical piston movement.
Read and record the temperature, pressure and flowrate of the liquid during flow.
Read and record the volume displayed on the dispenser when the displacer reaches the end point of its stroke.

Figure A.1 — Typical uni-directional pipe prover (Extracted from ISO 7278-2:19882))

Figure A.2 — Typical bi-directional straight-type piston pipe prover (Extracted from ISO 7278-2:19882))

Figure A.3 — Typical bi-directional U-type pipe prover (Extracted from ISO 7278-2:19882))

Figure A.4 — Typical small volume pipe prover with internal valve (Extracted from ISO 7278-4:19992))

Figure A.5 — Typical small volume pipe prover with external valve (Extracted from ISO 7278-4:19992))

Figure A.6 — Typical full stroke type pipe prover

Figure A.7 — Calibration of pipe prover (water draw method)

Figure A.8 — Calibration of full stroke type pipe prover (water draw method)

Figure A.9 — Calibration of a pipe prover (master meter method)

Figure A.10 — Verification of measuring systems for tank containers connected with pipelines

Figure A.11 — Verification of measuring systems on road tankers

Figure A.12 — Verification of measuring systems for LPG under pressure

Figure A.13 — Verification of LPG dispensers