Ch 9 cargo sampling

ZODIAC MARITIME AGENCIES LTD GAS OPERATIONS MANUAL 9.1 Form Issue Date Approved : : : : GOM 002 05-05-02 M.J.R CARGO SAMPLING Sampling Equipment and Procedures 9.1.1 Shipboard Equipment Cargo tanks are normally fitted with at least three independent sampling lines: 1) Line extended from external sampling point to the bottom of the cargo tank 2) Line extended from external sampling point to the middle height of the cargo tank 3) Line extended from external sampling point to the top (about 98% of total tank height) of the tank Sampling points on the tank dome present a stainless steel connection for the sample container 9.1.2 Shore Equipment As indicated two types of samples can be taken to analyse liquefied gas cargo: 1) A sample of the vapour phase (cargo or cargo tank atmosphere) 2) A sample of the liquefied gas To take the above sample, the following equipment can be used: I) Pressure bottles with either one or two valves 2) Rubber or plastic sample bags 3) Glass pipettes The method of sampling and equipment to be used may vary according to the cargo to be sampled and the pressure and temperature at which such cargo is carried 9.2 Considerations on Equipment and Procedures It is recognised that the greatest potential hazards from sampling occur when attempts are made to connect basically incompatible standards of ship / terminal equipment The following recommendations are issued: /storage1/vhost/convert.123doc.vn/data_temp/document/tah1554800567-1959494-15548005676829/tah1554800567.doc Page of ZODIAC MARITIME AGENCIES LTD GAS OPERATIONS MANUAL Form Issue Date Approved : : : : GOM 002 05-05-02 M.J.R 1) Standard for sampling connection fittings Ship's tank sampling points should present a stainless steel pipe with an approved female parallel 'thread connector The connection is specified female to provide best protection to the thread and the pipe should be such as to ensure that the connection is robust enough to withstand marine service and up to 3.5 kg weight of sample cylinder 2) It is recommended that sampling connection is isolated by two valves 25mm apart to permit access and as a precaution against hydrate formation at the primary valve They should be adequately supported and back welded or otherwise locked 3) There should be a clear space around the stub piece sample connection to allow for spanner access to the connection nut 4) Overall consideration must be given to personnel access and attachment of sampling equipment 5) Sample containers Construction of sample containers should be to a recognised standard and of material suitable for the gas to be handled For obtaining samples from ships the following design features are recommended: I) Containers should be fitted with inlet and outlet valves to permit "through flow" purging with suitable inert gas prior to use (Helium is recommended as being most suitable for use with gas chromatography analysis) 2) A T-piece connection with bleed valve should be attached to the sample container inlet valve ending in an approved metric threaded point (The bleed valve is recommended in order to depressurise and therefore prove effectiveness of shut-off valves prior to disconnection) Difficulties in connecting the sampling container to the ship's sampling point may be met due to different thread standards (metric and imperial) and accessibility to the sampling point It must be appreciated that under no circumstances should the sampling point be placed under strain whilst taking the sample 9.3 Procedures Involved in Taking Samples 1) During the sampling process, all personnel involved must wear appropriate protective equipment This should include protective clothing, gloves, goggles and when there is a risk from toxic gas, breathing apparatus Personnel observing the sampling procedure should keep a suitable distance away from the sampling location 2) As laid down under Chapter 18.1 of the IGC Code, all concerned are to be properly informed of the nature of the cargo being handled and the precautions to be observed This should include a full description of the physical and chemical properties, countermeasures against accidental personal contact, firefighting and other emergency procedures This information is available on board in the form of Chemical Safety Data Sheets as /storage1/vhost/convert.123doc.vn/data_temp/document/tah1554800567-1959494-15548005676829/tah1554800567.doc Page of ZODIAC MARITIME AGENCIES LTD GAS OPERATIONS MANUAL Form Issue Date Approved : : : : GOM 002 05-05-02 M.J.R supplied in Appendix of the Tanker Safety Guide (Liquified Gas) 3) When drawing liquid samples it is imperative that sufficient ullage or vapour space is left in the sample container to allow for liquid expansion due to the temperature increasing to ambient Proper ullage will be confirmed if the sample container is held upright after filling (i.e ullage tube at the top) and the top valve opened until only vapour (rather than liquid) is emitted 4) A responsible officer should be present when any sample is being drawn from ship's tanks by a terminal representative or third party inspector The officer should be fully conversant with all aspects of the ships sampling system including the operational characteristics of all valves He should clearly recognise that this duty is to ensure that sampling is authorised and carried out in a safe manner, regardless of who is actually performing the sampling operation Details of sampling operations shall be recorded in the Cargo Operations Log Book If the Chief Officer has any doubt about the sampling procedures adopted by an Independent Cargo Inspector he shall immediately inform the Master, who in turn shall decide whether to file a Letter of Protest to the cargo owners I shippers The Master shall issued a Letter of Protest if the actions of the Independent Cargo Inspector / Terminal representative may affect the quality of cargo or could give rise to a claim by the Charterer or cargo owners /storage1/vhost/convert.123doc.vn/data_temp/document/tah1554800567-1959494-15548005676829/tah1554800567.doc Page of ... is available on board in the form of Chemical Safety Data Sheets as /storage1/vhost/convert.123doc.vn/data_temp/document/tah1554800567- 195 9 494 -155480056768 29/ tah1554800567.doc Page of ZODIAC MARITIME... actually performing the sampling operation Details of sampling operations shall be recorded in the Cargo Operations Log Book If the Chief Officer has any doubt about the sampling procedures adopted... if the actions of the Independent Cargo Inspector / Terminal representative may affect the quality of cargo or could give rise to a claim by the Charterer or cargo owners /storage1/vhost/convert.123doc.vn/data_temp/document/tah1554800567- 195 9 494 -155480056768 29/ tah1554800567.doc