Machinery Problems with fuels bunkered in Houston area ports On April 26 2018, Viswa reported that six vessels had experienced machinery fuel problems when using fuel bunkered in the US Gulf, mainly in the Houston area (Texas City, Bolivar Roads, Deer Park and Houston).
The number of ships experiencing problems has now increased to 15. Multiple suppliers and barges have supplied these fuels.
The most common problem continues to be sticking of main engine fuel pumps. Multiple vessels have also reported abnormal wear of the generator fuel pump plunger and barrel. Some pictures of the machinery problems are attached to this update. One of the vessels reported hard sludge formation in the purifier.
Routine analysis indicated that these fuels conformed to the ISO 8217 specifications with catfines on the higher side between 34 ppm and 57 ppm (but within the specification limit of 60 ppm) and Acid number values between 0.60 mg KOH/g and 0.78 mg KOH/g (normally 0.20 to 0.30 mg KOH/g).
Additional analysis on the fuels identified the following: ASTM D7061 test for Reserve Stability Number (RSN) values were between 9.2 and 14.1. This is high.
Problem Fuel Identification Number (PFIN) (an algorithm developed by Viswa Lab based on RSN, XE, Micro Carbon Residue, Asphaltene and CCAI) for these fuels was also found to be high between 151 and 290.
If the PFIN exceeds 130 there is an 85% chance of piston ring breakage. The Xylene Equivalent (XE) test results for most of the fuels indicated a very high value of 71.
As per engine maker DU Sulzer, high Xylene Equivalent values are connected to fuel pump seizure.
Class NK advises that Xylene Equivalent values over 30 can lead to machinery problems.
Tel: USA (713) 842-1985
Fax: USA (713) 842-1981