2000-11-27 Regular Meeting - Laserfiche WebLink

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0 • 0 9 Sulphur Sulphur content represents a loss of energy con- tent in the fuel. Very low levels of sulphur may represent some risk of deposit formation in the form of alkaline ashes in crosshead engines, while high sulphur content combined with reduced load, low temperature and moist scavenge air, can lead to corrosion. Ash Gives a useful indication of the amount of incom- bustible impurities in the fuel. Such impurities may include sodium, vanadium and powder, which can remain in the fuel in high concentrations after catalytic cracking. Such particles are very abrasive and can cause rapid wear of the cylinders and high pressure fuel system components, unless they are efficiently removed in fuel pre-treatment. Silicon in the fuel may also originate from sand. Catalyst fines can cause serious abrasive wear Pour Point (upper) This test is carried out for fuels with viscosity below 100cSt at 50 deg. C only. It is an important test in relation to storage and handling of residual and distillate fuels in outdoor tanks, equipment for emergency use as well as ship bunker tanks exposed to low temperatures. Failure of the fuel to flow at low temperatures can cause engine stoppages and adversely affect the safe operation of the vessel. High V/Na ash can cause high temperature corrosion Total Sediment Existent This test gives an indication of the cleanliness and stability of the fuel and its tendency to form sludge which can result in clogging of fuel lines and centrifuges. Net Specific Energy Purchase of fuel is basically purchase of energy. This is a calculated value based on the BSMA 100, 1989 formula using test results from the analysis. Incompatible fuels can result in excessive sludge Importance of Proper Sampling Sampling kits with programme manual for sampling The DNVPS Line Sampler • Specially designed for Custody Transfer Sampling • Fabricated from top quality stainless steel yet light and portable • Custom made to suit your vessel's bunker manifold • Conveniently bolted on in minutes • No hot -work or drilling is required • Five -litre disposable plastic container prevents contamination • Collected sample can be thoroughly shaken and divided into three, four or more of one -litre bottles. Other samplers restricted to only three samples. • Security sealed during sampling to prevent tampering Continuous drip sampling at custody transfer point Important Note FQT Sampling Equipment Upon formalisation of an FQT agreement, each participating vessel is provided with a Sampling Kit containing detailed programme and sufficient sample bottles for 10 bunkerings. These bottles are specially made of high density polypropylene (HDPE) and are complete with bottle plugs, security seals, bottle labels, des- patch cartons and a comprehensive programme manual. Custody Transfer Sampling DNVPS advocates that there should be only one single official sampling point and this is at the point of custody transfer, which is the point where the product changes hands from the deliverer to the receiver. The custody transfer point in this instance is the interface between the ship's bunker manifold flange and the bunker hose flange. A sampling device should be installed at this location for taking a continuous drip sample throughout the whole dura- tion of the bunkering. It is a common practice for the supplier's representative to ask the Chief Engineer to sign sample labels in advance of bunkering. This practice of pre -signing the sample label must be avoided as it will put you in a legally disadvantageous position if the labels are misused. If offered a sample by the supplier where the contents were not taken at the point of custody transfer or where sampling was not witnessed, it is important to sign `For receipt only, source unknown.' DNVPS has designed a line sampler which makes sampling very con- venient for the shipboard staff. This is available on order. The one -litre sample bottles are sealed, labelled and signed by all parties present. One sample is offered to the supplier and one retained on board the ship for safe keeping in case further testing is required. In some instances, the charterer and the shipowner may both be in the FQT programme and may require samples to be tested separately. The additional two samples are intended fof this purpose. Details of sample preparation and documentation are contained in the Manual provided in each kit. It is important to ensure that a proper sampling device is used so that a representative sample can be taken during bunkering. A representative sample is essential to ensure that the DNVPS analysis results and technical advice provided to the vessel are valid and useful.