Tests

Case of a first expansion stage station equipped with a gas regulator and a pressure limiter.

The pipe line situated after the pressure reducing station must undergo;

A mechanical resistance test at 1 .5 times working pressure with a minimum of 3 bars. A leak test at working pressure.

These two tests are performed using nitrogen, air or propane.

Case of a first expansion stage station equipped with a gas regulator and no pressure limiter.

The pipe line situated after the pressure reducing station must undergo:

A hydrostatic mechanical resistance test at 1.5 times working pressure (propane 30 bars and butane 12 bars). This test uses mains water or well water. (maintain pressure for 20 minutes).

If there is no leakage, the line filled with water is drained.

Compressed air then needs to be blown through all of the pipe lines, several times, by opening all of the low sections of the pipe line.

3MCO recommendations

3MCO regulations and recommendations as well as good practices require:

Either a pressure reducing station equipped with a gas regulator and a pressure limiter placed at the tank outlet valve of the gaseous phase

Or a gas regulator without a pressure limiter placed at the tank outlet valve of the gaseous phase.

The limiter must be tared at a pressure exceeding that of the gas regulator often from 15% to 16%.

Example: Gas regulator outlet pressure 1.5 bars. Limiter outlet pressure 1 .750 bars.

The pressure limiter is used in case of a gas regulator defect as a backup and to ensure a constant pressure of 1 .750 bars.

If this limiter is absent and the gas regulator is defective, tank pressure will spread throughout the pipe line.

At a temperature of 15°C, pipe line pressure will be the same as that of the tank, in other words 7 to 7.5 bars depending on the propane/butane mix.

Once these operations have been performed, conduct a leak test at 1.5 times working pressure with a minimum of 3 bars.

This test is performed using nitrogen, air or propane.

Case of a second expansion stage station.

This station is generally equipped with:

a 1,/4 turn stop valve placed before the gas regulator

a gas regulator adapted to the flow and the pressure indicated by the builder

(the gas regulator is fitted at its inlet with a strainer filter)

a 1,4 turn stop valve placed before the regulator an 80 microns basket strainer

a solenoid safety valve

a gas regulator adapted to the flow and pressure indicated by the builder.

The basket strainer is used to trap the solid particle deposits that can be found in the pipe line in order to avoid their settling on the solenoid valve’s sealing.

The pipe line and the components situated after the 1,4 turn valve must undergo a leak test

at 1.5 times working pressure.