LP 06/2019 Notice Ship Tank Damage Due to Off Spec WPA Cargos
The Club has recently found that some Tunisia-exported Wet Process Phosphoric Acid (WPA) cargo are high in Chloride and Fluoride content and carrying such off spec cargos is very likely to result in ship tank damages. For Members that plan on shipping WPA from Tunisia producers, it will be prudent to engage an independent surveyor before loading.
Background
The Club has been notified by associated lawyers that as the main producer of WPA in Tunisia fails to bring the Chloride and Fluoride impurities under control, it has been purchasing WPA directly from the factory operated by its parent company at La Skhira and mixing it with the defective product in the shore tanks before loading onto vessels.
Meanwhile, WPA production has been slowing down due to local social unrest at their nearby Phosphate rock mine due to unionisation of the workers. Such circumstances have pushed some WPA exporters to decide to simply ship the defective WPA product even with its high Chloride and Fluoride content.
Truthfulness of test results
Some WPA producers have just recently terminated their contract with their reportedly 1st class cargo quality inspection company and moved over to a local outfit for testing of cargo parameters. According to the Club’s contacts, this new firm is believed to be fabricating specifications for the products as far as those 2 standards (Chloride & Fluoride content) are concerned. The London lawyers have been working on several cases where ship tanks are damaged for carrying off spec WPA cargos. Local surveyors have also proved that the off spec products were causative of the damage.
Advice to Members
To make sure of contractual specifications and that Owners can claim losses from the Shipper in the event of any ship tank damages, Members that plan on shipping WPA from Tunisia should have shore tank samples obtained by a trusted surveyor and tested. More specifically, it will be prudent to:
1. Obtain permission from producers to attend and sample from their shore tanks, depending on mix of WPA cargos and shore tank/terminal ownership.
2. Have the shore tank samples sent to the nearest independent laboratory by an appointed agent and do not let the Shipper change the samples without being noticed.
3. Obtain the following parameters in accordance with BS 4258-1989 (the current version) – Methods of Test for Phosphoric Acid for Industrial Use, parts 1-10 or equivalent procedures – use of optical emission is acceptable instead of optical absorption:
l Density at 20oC (g/cm3)
Density determination by gravity bottle (Le Chatelier Method) is suitable.
l Suspended solids
Suspended solids are determined by any standard gravimetry procedure.
l P2O5 acid strength
l Calcium as CaO
l Iron as Fe2O3
l Sulphate as SO4
l Fluoride as F
l Silicon as SiO2
l Magnesium as MgO
l Chloride as Cl
l Aluminium as Al2O3
4. The WPA product should be sampled every 2 hours or so whilst loading, including after any shore-stops. Such samples will provide excellent evidence for Owners should any damage be found at a later stage.
5. As usual, first foot and final tank samples are also to be taken and retained as evidence. Survey and analysis costs are estimated to be around EUR 4,000 - 5,000.
6. The Chief Officer must monitor and record the loading temperature at the vessel’s manifold throughout the loading, and after any shore-stops, because if the shore tanks become depleted, such terminals have a habit of pumping cargo direct from the production line at an elevated temperature of > 45oC which means that the cargo can become dangerously aggressive. If the temperature exceeds 45oC, then the Master must inform shore terminal and stop loading until temperature is decreased. Also, a Note of Protest must be issued.
7. All samples to be photographed, recorded in sampling report and to be jointly taken and witnessed as far as possible with Shipper’s Surveyors.
8. All samples (including at discharge port) must be fully documented and a complete chain of custody undertaken, full detailed and signed labels must be used.
9. Through the voyage, cargo is to be recirculated and cargo temperature recorded.
10. Post discharge and washing, tank surfaces to be carefully examined to establish condition. Photos (including close-up zoomed pictures) are to be taken and compared against earlier available photos of tanks taken prior to vessel carrying the subject WPA cargo.
11. Please fix future WPA cargo charter parties with the following clause wording:
PROTECTIVE PHOS. ACID CLAUSE：
CARRIAGE OF PHOSPHORIC ACID, WPA, MERCHANT OR FERTILISER GRADE, CHARTERERS SHALL ONLY LOAD CARGOES THAT MEET THE FOLLOWING SIX CRITERIA:
(1) LOAD, CARRIAGE AND DISPORT TEMPERATURE < 45oC
(2) P2O5 IS BETWEEN 48-54%
(3) SO4= < 4% WT
(4) FE2O3 < 1.5% WT
(5) CL− <200 PPM WHERE F− < 0.2% WT
(6) CL− <100 PPM WHERE F− > 0.2% WT, BUT NO MORE THAN F− 0.4% WT MAX.
OWNERS’ SURVEYOR TO BE PROVIDED FULL ACCESS TO LOAD PORT SHORE TANKS PRIOR TO AND DURING LOADING AND IS TO BE PERMITTED TO TAKE AND RETAIN SAMPLES OF THE CARGO WITHIN SUCH TANKS AS AND WHEN REQUIRED.
This will undoubtedly help improve cargo quality and provide the Owner with some convenience when taking shore tank samples. Still, the Club would like to point out that the above clause cannot guarantee zero corrosion damage to the cargo tanks. Molybdenum content in tanker’s stainless steel can also be relative, more information can be found on Club website at:
https://mp.weixin.qq.com/s?__biz=MzA3MTkyMzU2MQ==&mid=.
This article is based on RR&CO Guidance Note Lifting Phos. Acid from La Shkirra, Tunisia 2019, for Members’ reference only. For further information, please contact your manager at the Club.