ISO 3171 Petroleum liquids - Automatic pipeline sampling
13 Safety precautions
13.1 It is essential that the safety precautions set out in this clause should be applied rigorously as the minimum necessary for safe operation. These precautions should be used in conjunction with the appropriate national and/or international safety regulations. Local regulations should always be complied with, but if these are less demanding than the precautions in this clause the latter should also be considered (see also ISO 3165).

13.2 Sampling equipment, and sample receivers and containers should be properly designed for the pressures to which they may be subjected during use or subsequent handling. They should be pressure tested to at least one and a half times the maximum operating pressure before being taken into use, and thereafter at regular intervals dictated by the nature of the apparatus and the pressure range involved. Each vessel should be marked with the date of the last pressure test, the maximum permissible working pressure at ambient temperature and the tare weight. The marking should be etched on the vessel or stamped on a tag firmly attached to it.

13.3 Care should be taken to ensure that the maximum design pressure of the sampling system is not exceeded even if abnormal pressure develops in the pipeline or is generated by the sampler itself. Protection should be provided by fitting suitable relief valves.

13.4 When filling sample receivers or containers sufficient ullage should be left to allow for expansion. lt is recommended that a safety device be fitted to give a warning when this safe filling limit is reached. The following precautions should also be observed.
a) A receiver should be fitted with a pressure relieving device to limit the pressure in the vessel to within its certified maximum working pressure.
b) Removable receivers or containers should be constructed and certified to withstand at least one and a half times the maximum pressure and any extreme temperatures that can possibly be encountered during subsequent handling.

13.5 Any materials used in the construction of the receiver which may be in contact with the sampled liquid should be immune from attack by any component of that liquid.

13.6 When handling receivers and containers, it is vital to ensure that there is no spillage or vapour release of flammable or toxic material.

13.7 Care should be taken to avoid breathing petroleum vapour during the sampling operations. Protective gloves of hydrocarbon-insoluble materials should be worn. Eye shields or face shields should be worn where there is a danger of splashing. Additional precautions may be necessary when handling crude containing hydrogen sulfide.

13.8 All electrical components used in connection with automatic sampling apparatus situated in a classified area should be appropriate to the classification of the area and should conform to the appropriate national and/or international safety regulations.

13.9 When handling leaded fuels the national standard safety regulations should be meticulously observed.

13.10 When transporting samples, consideration should be given to the dangers of transporting removable receivers and containers, particularly by air. Reference should be made where necessary to the appropriate national and/or international safety regulations regarding the sea, land or air transport of flammable samples and pressurized sample containers.

13.11 lt isessential to bond and earth the complete sampling system during- any discharge of volatile hydrocarbons in order to dissipate any static electricity which may be generated. lt is also necessary to earth pressurized sample containers whenever liquid orvapour under high pressure is discharged from them, for example during purging.