ASTM D5842 Sampling and Handling of Fuels for Volatility Measurement
ASTM D5842 Standard Practice for Sampling and Handling of Fuels for Volatility Measurement
6. General Comments
6.1 Sample Containers:
6.1.1 Sample containers are clear or brown glass bottles, fluorinated high-density polyethylene bottles, or metal cans. The clear glass bottle is advantageous because it is easily examined visually for cleanliness, and also makes visual inspection of the sample for free water or solid impurities possible. The brown glass bottle affords some protection from light. The only cans acceptable are those with the seams soldered on the exterior surface.
6.1.2 Cork stoppers, or screw caps of plastic or metal, are used for glass bottles; screw caps with inserted seals only are used for cans to provide a vapor-tight closure seal. Corks must be of good quality, clean, and free from holes and loose bits of cork. Never use rubber stoppers. Contact of the sample with the cork can be prevented by wrapping tin or aluminum foil around the cork before forcing it into the bottle. Screw caps must be protected by a cork disk faced with tin or aluminum foil, an inverted cone polyseal or other material that will not affect petroleum or petroleum products. The fluorinated bottles are supplied with polypropylene screw caps.
6.1.3 Sample size is dictated by the test method to be used. One litre (32 oz) bottles or cans are generally used for manual vapor pressure testing. The mini-vapor pressure methods need a much smaller sample and it can be taken in a 125 mL (4 oz) bottle. See Fig. 1 .
6.1.4 All sample containers must be absolutely clean and free of foreign matter. Before reusing a container, wash it with strong soap solution, rinse it thoroughly with tap water, and finally with distilled water. Dry completely, stopper, or cap the container immediately.
6.2 Sampling Apparatus - Sampling apparatus is described in detail under each of the specific sampling procedures. Clean, dry, and free all sampling apparatus from any substance that might contaminate the material. If necessary, use the clean procedure described in 6.4.
6.3 Time and Place of Sampling:
6.3.1 Storage Tanks - When loading or discharging fuels, take samples from both shipping and receiving tanks, and from the pipelines if required.
6.3.2 Ship or Barge Tanks - Sample each product after the vessel is loaded or just before unloading.
6.3.3 Tank Cars - Sample the product after the car is loaded or just before unloading.
NOTE 1 - Time, place, and other details of sampling not covered in this practice are normally determined by contractual agreement or regulatory requirements.
6.4 Obtaining Samples:
6.4.1 Directions for sampling cannot be made explicit enough to cover all cases. Extreme care and good judgment are necessary to ensure samples that represent the general character and average condition of the material. Use lint-free wiping cloths to prevent contaminating samples.
6.4.2 Many petroleum vapors are toxic and flammable. Avoid breathing them or igniting them from an open flame or a spark. Follow all safety precautions specific to the material being sampled.
6.4.3 Do not sample dead legs or relief lines. Do not sample stand pipes that are not slotted or perforated! Fig. 2 is an example of an adequately slotted stand pipe. At a minimum, the stand pipe should have two rows of slots slightly staggered in the vertical plane.
6.4.4 Rinse or flush sample containers with product and allow it to drain before drawing the sample. If the sample is to be transferred to another container (for testing other than DVPE), the sampling apparatus also is rinsed with some of the product and drained. When the sample is emptied into this container, upend the sampling apparatus into the opening of the sample container.
6.5 Handling Samples:
6.5.1 Protect all samples of light fuels from evaporation. The sampling apparatus is the sample container for vapor pressure. Keep the container tightly closed after the sample is collected. Leaking sample containers are not suitable for testing. Cool volatile samples to 0 to 1°C (32 to 34°F) after delivery to the laboratory and before opening the container. Maintain at this temperature throughout transfer and handling, if at all possible.
6.5.2 Never completely fill a sample container. Fill the container to 70 to 85 % capacity to allow adequate room for expansion. Subsequent testing for vapor pressure requires this level of container fill.
6.5.3 The first sample aliquot removed is for vapor pressure testing. The remaining sample in the container is not suitable for a vapor pressure determination but is suitable for other testing.
6.6 Shipping Samples - To prevent loss of liquid and vapors during shipment, place internal seals in the metal containers, screw the caps down tightly and check for leakage. Observe all shipping regulations applying to the transportation of flammable liquids.
6.7 Labeling Sample Containers - Label the container immediately after a sample is obtained. Use waterproof and oilproof ink or a pencil hard enough to dent the tag, since soft pencil and ordinary ink markings are subject to obliteration from moisture, product, smearing, and handling. Typical label information includes the following information:
6.7.1 Date and time (the period elapsed during continuous sampling),
6.7.2 Name of the sample (location),
6.7.3 Name or number and owner of the vessel, car, or container,
6.7.4 Brand and grade of material; and
6.7.5 Reference symbol or identification number.
6.7.6 Labeling should conform to all applicable federal, state, and local labeling regulations.
