Marine Corrosion & Expert Consultancy Services
Amtec Are specialists & experts & consulting corrosion engineers dealing with all aspects of marine corrosion including paint & coating breakdown problems & failures. Amtec specialise in all rust & corrosion problems that occur in vessels such as tankers, VLCC's, FPSO's, product carriers, bulk carriers, container ships & ferries. Premature corrosion failures can be a result of poor specification or poor material quality.
Amtec offer specialist training courses, workshops & seminars to all grades of ships personnel from technical directors, superintendent engineers, masters, officers to deck crew as an aid to ongoing & continuing professional development. Courses deal with all aspects of marine corrosion, coating specification, & maintenance that are relevant to operators of vessels. A specialised course is offered that specialise's in the new building process dealing with all stages from specification, through incoming steel & coating quality issues, block stage issues to do with blast & weld quality, right up to final commissioning & first year guarantee inspections. Special courses are available on the implementation of the new IMO (International Maritime Organisation) Performance Standard for Protective Coatings (PSPC) to new ship construction that illustrate how best to take advantage of the new situation and pay special attention to the gray areas in the standard that may represent pitfalls for the unwary.
Amtec's experienced inspectors can undertake a comprehensive assessment of the corrosion & coating condition on the vessel, both on the exterior hull & the tank & hold interiors. Inspections can be carried out both in dry dock & in normal service or at sea. Inspections can be carried out on behalf of vessel owners, managers, charterers, shipyards, paint & coating companies. Claim related inspections may also be progressed in accordance with the wishes of the legal profession. State of the art tests & equipment are used to assess the condition of the coating and to quantify any corrosion present. Paint, Coating & Rust samples can be taken for subsequent laboratory analysis during investigations into the causes of failure. Amtec carry out pre purchase inspections that deal with all aspects of the quality of the hull and its anti corrosive systems. This would include coating condition & projected remaining lifetime, the extent of corrosion & metal loss together with a full report on any sacrificial anodes or ICCP system. A report detailing any remedial work necessary to extend the lifetime of the coatings or hull metal would be provided. Post purchase inspections & planned maintenance evaluations are regularly performed by our personnel. these enable forward planning for any coatings or paint work that would be necessary at the next major refurbishment together with ongoing coating repairs and anode replacement that could be carried out by the crew during normal service. Amtec can provide advice & information on the repair of coatings in service - particularly where repeated paint repairs have failed.
The maintenance and repair of ballast tanks is in many cases the most costly coatings decision that confronts a vessel owner or manager. Amtec's new in-situ coating barrier properties measurement technology can make this a more easily quantifiable decision. Such measurements are particularly beneficial were blistering of the coating (in theform of blister rashes or rashes of blisters at welds & cut edges) or premature rusting & corrosion is occurring at edges & welds that result in the tank being classified as being in Fair or Poor condition. Where ballast lines, valves or VRC valve control lines are pitting or corroding Amtec can investigate & offer solutions to the problem. Problems with retained blasting grit or other contamination are also commonly investigated.
The maintenance and repair of Cargo Holds is a costly issue due the the time taken for the staging, blasting & coating operations together with their associated off hire costs. Aggressive cargos such as iron ore, coal, limestone, bauxite & sulphur can dramatically reduce the time required between major repairs. Often cargo damage is associated with poor coating application or curing just prior to delivery or after repairs.
Tank top pitting and under deck corrosion can be a serious corrosion problem - especially if these areas are left uncoated. The problem can be even worse if the inert gas or the crude oil are high in sulphur. Crude oils containing SRB (Sulphate Reducing Bacteria) may combine with sea water washing to promote microbially induced corrosion (MIC). This problem can be made worse if TMCP (Thermo Mechanically Controlled Process) high tensile steel of AH32 or AH36 grades have had poor surface preparation. For more details on this subject consult the reference library on this site. Tankers trading in white oils & naphtha can have severe pitting & crevice corrosion problems with stainless steel heating coils made from 304 or 316 grades.
Selecting the correct material ( grade of stainless steel & correct surface passivation) is crucial if in service failures are to be minimalised . This is especially true of pumps & pipe work in highly corrosive service conditions.
High Tensile Steel
The use of TMCP high tensile steel in highly corrosive environments needs careful management. For more details on this subject consult the reference library on this site.
Heating coils in both product carriers & tankers can interact with the products being transported . Stainless steel heating coils in product tankers carrying naphtha require special attention in the new building and commissioning stage to ensure that the surfaces are in good condition and are correctly passivated using suitable chemical treatment before the vessel enters service. Copper based heating coils in crude oil tankers need special attention to prevent excessive tank to pitting or other galvanic corrosion problems.
Stainless Steel Corrosion & Passivation
Most of the lower grades of stainless steel are not immune to corrosion in marine environments. Grades containing less than 18% chromium & 8% nickel will pit & crevice in marine environments unless special care is taken to mitigate the problem.
Inert Gas Systems
Inert gas, IG ,systems have been used to try to control the corrosion in ballast tanks. For this to be successful the levels of both sulphurous gases and of oxygen need to be carefully controlled. Carbon dioxide induced corrosion can also be a problem with this approach.
Dehumidification systems can be very successful in controlling the corrosion in closed spaces. Split fore peak tanks in VLCC & ULCC tankers are candidates for this technique as hey are often infrequently used.
Vapour Phase inhibitors
Areas such as the inside void spaces of hatch covers often are uncoated & the corrosion is controlled by the use of vapour phase inhibitors .These products have a limited lifetime of only a few years & care should be taken to replace them before they become completely exhausted. Amtec can provide specialist advise in the selection of vapour Phase Inhibitors (VPI) or volatile corrosion inhibitors (VCI).
Coatings and anodes can either work with or against each other. Ideally cathodic protection prevents corrosion at damaged areas in the coating, however excessive calcareous deposit build up can result in metal loss rather than prevent it. Amtec's anode optimisation strategy ensures the right balance.
Hull Service Lifetime Prediction (HSLP) is essential to the vessel owner who wishes to have a successful strategy for maintenance and repair. It is also required in order to make informed choices about vessel purchases and sales.
Economic modeling of the most economic strategy for vessel protection requires a carefully balanced choice between the quality of the coating and the number and positioning of the cathodic protection system anodes. Amtec can analyse a number of vessel protection strategies.