Marine valves
Colour coding of marine valves
To enable the fast identification of pipeline media, pipes and valves on ships are normally given a colour-code. Some examples are:
• Green = sea water
• Blue = fresh water
• Yellow = lube oil
• Silver = steam
• Grey = non-flammable gases
• Brown = fuel oil
• Red = fire line
• Violet = acids and alkalis
• Yellow = inflammable gases
• Black = waste matter
CPVC, PVDF, etc. More exotic materials are also available. Stra-Val for one has a range of sea-water valves( up to 3”) available in titanium, Hastelloy, Monel and Alloy 20. Similarly, leakage and failure of gaskets, packings and seals can also be an issue on board ships, with problems exacerbated by the extra vibration associated with vessels. Moreover, the often confined spaces and lack of proper access to valves can also contribute to improper installation of replacement parts. Pipes and valves on ships are also more prone to‘ foreign object deposits’ than equivalent systems on land. For this reason, strainers and filters are often fitted upstream of critical valves, with regular flushing of pipelines also recommended. Not surprisingly, technician training courses for the marine sector consistently emphasise the need for regular checks of items such as valves. They also discuss maintenance and repair procedures which may be less familiar to those onshore. In an emergency situation, for example, a temporary solution for leaking pipes and valves can be the use of a‘ cement box’. This relies on fast-setting cement which is poured into an improvised wooden box around the failed component. The solution may sound crude but can enable the vessel to continue its journey until proper repairs can be effected at port.
Raising the safety bar
To ensure ships’ integrity, and improve safety for passengers and crew, several bodies worldwide investigate accidents, identify root causes, and recommend improvements in system designs as well as operational procedures. A quick search reveals that valve-related incidents can certainly be found among the list of accidents, although typically the problems are not due to the valves per se. For example, a report by Marine Insight ii discusses how a tanker carrying MTBE( methyl tertiary butyl ether) suffered a cargo overflow though a drop valve on a cargo tank. Apparently, the ship’ s practice was to tie up the manual drop valves with rope to indicate they were in the closed position. In a chain of errors, not only was a specific valve in fact not properly closed, but an officer failed to correctly identify a subsequent audible alarm. Moreover, multiple valves were opened up which were not required plus there was a failure to physically check the status of the valves. Needless to say that corrective actions have been taken. A second incident with a valve dimension involves a vessel named the‘ Joanne Marie’, which was found partially sunk after having being moored and deactivated at a shipyard in the USA. The cause was discovered to be an obstructed check valve on a bilge pump discharge line. Apparently a wire nut had become lodged in the spring-loaded check valve. That alone would not have led to the sinking, had the shutoff valve located before the through-hull pipe not been left open. Procedures have since been modified to prevent such incidents in the future.
Naval valves
When it comes to valves for naval vessels, top quality and performance are of course more important than ever. Hence IMI Process Automation refers to‘ custom-designed valves [ that ] are engineered to withstand diverse water conditions, ensuring longlasting durability and optimal functionality. Each valve is meticulously tested and certified to industry standards, guaranteeing their reliability and adherence to stringent quality benchmarks’. Meanwhile, Shipham Valves indicates that‘ material selection becomes critical in the supply of the most cost-effective through-life solution. Our products are manufactured in various specialist materials including nickel aluminium bronze, bronze, duplex stainless steel, super duplex stainless steel, Hastelloy ®, Monel ®, titanium, Inconel ® and zirconium in sizes ranging from ∞ to 48 inches’.
Increasing sophistication
Many observers suggest that the marine industry as a whole is poised for transformation, in step with changes in other industries. Hence as ships become increasingly complex, so the demand for more automated and sophisticated control systems will grow. Remote monitoring will also be more widely deployed on board, in line with the trend to invest in smart systems. Other drivers that could lead to investment in more sophisticated valve systems include the enhanced focus on safety and compliance, the drive for sustainable solutions, and advancements in cybersecurity. ii https:// www. marineinsight. com / case-studies / failure-to-check-status-of-valves-on-deck-leads-to-cargo-overflow /
46 Valve World June 2025 www. valve-world. net