Sampling procedures ways evacuated container method is as follows:
1) Evacuation sample container to a pressure of 1 mm Hg or below. (Use cylinder having facilities evacuation and tested in a vacuum). Before use, the vacuum can be tested with a vacuum gage.
Note: As an alternative to cylinder evacuation, the cylinder can be charged up to a positive pressure with inert gas in the analytical techniques used. A gas that can be used is hydrogen or helium gas. Air content in the sample container can be reduced to the lowest prices by purging the gas pressure or by evacuation and filled with gas suppressant. Gas content suppressor can be used to modify the method of analysis.
Equipment arrangement shown in Figure 10.
Figure 10. The sampling gas – evacuated Container Method
2) Open the valve at the sampling point and clean the dirt collected at that point.
3) Put the sample container as shown in Figure 10. For purging, loosen ties sample container inlet valve (valve 3) such that flow occurs purging of the sample line to the inlet valve the sample container.
4) Perform purging slowly into line with the sample gas to expel the air by opening a portion of the vent valve (Valve and sampling valve (Valve 1) so as to flow in the sample gas line and a pad out the inlet valve and out of the sample container vent valve (Valve 2).
Next, tighten relations on the inlet valve and close the sample container sampling valve (Valve 1). Let the sample line pressure becomes atmospheric pressure and then close the vent valve (Valve 2).
5) Open full sampling valve (Valve 1) and open the sample container pelanpelan inlet valve (Valve 3), let it be increase the pressure until the pressure source or a little below it. The presence of condensate can be avoided if the sampling is done at lower pressure than the pressure source.
6) Close the sample container inlet valve (Valve 3) and sampling valve (Valve 1). Open vent valve (Valve 2) to relieve the pressure in the sample line.
7) Move the sample container and valve leak test by dipping in water or by using a leak detection solution. Perform valve blockage.