Laserfiche WebLink
• Section No 6 <br /> Revision No 0 <br /> Date September 5, 1991 <br /> Page 10 of 55 <br /> 6 3 3 Sample Container Preparation <br /> Depending on the requirements specified in the sampling and analysis <br /> plan, samples will be collected and transported using three primary <br /> containers stainless steel canisters, polymeric film bags (i e , Tedlar) , <br /> and adsorbent cartidges (i.e , activated charcoal) To provide maximum <br /> reliability and reproducibility of results, particularly with respect to <br /> reactive constituents at trace levels, special precautions are prescribed for <br /> the preparation of sample containers The preparation process involves four <br /> steps (1) leak check, (2) conditioning, (3) quality control analysis, <br /> and (4) documentation Each step is described in the following sections <br /> 6 3 3 1 Leak Check - All containers are leak-tested prior to <br /> conditioning Leak testing of bags is prescribed as follows <br /> Fully evacuate the bag Take care not to crinkle the PVF plastic <br /> film (especially next to the valve) Before complete evacuation <br /> occurs, reinflate the bag slightly with zero air, <br /> ■ Test the bag for leakage by fully inflating the bag to drum- <br /> tightness with zero air (which normally contains about 0 1 ppm <br /> hydrocarbon) Carefully store the bag being cautious about placing <br /> undue stress on the Swagelok valve stem If a mounting rack is <br /> unavailable, inflated bags may be placed on a clean level surface in <br /> an isolated area If bag remains drum-tight for 16 hours, it can be <br /> used for ambient air sampling applications, <br /> ■ After 24 hours, bags should be at least 90% full to be acceptable <br /> Leak testing of stainless steel canisters is prescribed as follows <br /> ■ Test as above, except pressurize to maximum design specifications, <br /> and then <br /> ■ Evacuate canister to prescribed subatmospheric (negative) pressure <br /> (typically -25 psig) , <br /> 6-10 <br />