Marine valves and actuators: types, applications and certifications

Marine valves are shut-off components designed to handle fluids on board yachts and vessels.

Here, corrosion resistance, low weight and compact dimensions become decisive requirements, because every circuit, from the water line to the drains, takes up little space and is often designed to be automated by an actuator rather than operated by hand.

Choosing the valves and their actuators is therefore no small matter: it affects the reliability, durability and safety of the onboard system. And it is on this ground that the value of the OMAL range is measured.

Types of marine valves: ball valves and butterfly valves
On board, ball valves and butterfly valves are used above all, both of which can be automated with an electric actuator or a pneumatic actuator. The former ensure reliable fluid shut-off, from the most compact lines up to the largest diameters and pressures. The latter serve the large-diameter water lines while keeping the weight low.

Among the OMAL valves, the MAGNUM is the lightweight, compact wafer version, a marine ball valve also available as a 316 stainless steel ball valve. The THOR split body flanged version covers larger diameters and pressures, with options such as a three way ball valve execution, reduced bore and stem extension.

The KRAVEN is the range's marine butterfly valve, available as a wafer butterfly valve or lug butterfly valve, with body and disc in cast iron, CF8M or aluminium bronze.

Product	Type	Onboard strength
MAGNUM Wafer	Ball valve	Lightweight version, maximum compactness
THOR Split Body	Flanged ball valve	Larger diameters and pressures
KRAVEN	Butterfly valve	Large diameters with low weight
EA IP68	On/off electric actuator	Automation without compressed air, IP68
AGO	Pneumatic actuator	DNV certified

Applications in the marine sector
On board, valves and actuators handle the main onboard fluid-handling circuits, in tight spaces and often set up for automation. They are used in:

Water treatment, the treatment of onboard water.
Ballast water treatment, the treatment of ballast water.
Sewage treatment, the treatment of wastewater.
Bilge extraction, the removal of bilge water.
Pool feeding and draining, filling and emptying onboard pools.
Scupper, deck drains and scuppers.

Certifications for marine valves
In the marine sector, valves and actuators must withstand the toughest conditions on board, and the certifications, verified by independent third parties, confirm the suitability of the components already at the selection and testing stage.

The DNV certification, issued by an international ship classification society, attests suitability for use on board according to classification rules: in our range it applies to the AGO pneumatic actuator. The RINA certification serves a similar purpose and is available on certain types of installation.
Depending on the product family, the conformities that also matter in industrial applications are added: Pressure Equipment (PED) CE/UKCA, the ATEX (Ex CE/UKCA) marking, SIL certification up to SIL3 (IEC 61508) and the Fire Safe qualification, plus TA Luft & Fugitive Emission on the ball valves.

Certification	Product / application
DNV	AGO pneumatic actuator
RINA	Available on certain types of installation
Pressure Equipment CE/UKCA	MAGNUM and THOR ball valves, KRAVEN butterfly valve
Ex CE/UKCA (ATEX)	MAGNUM and THOR ball valves, KRAVEN butterfly valve, AGO actuator
SIL up to SIL3	MAGNUM and THOR ball valves, AGO actuator
Fire Safe	MAGNUM and THOR ball valves
TA Luft & Fugitive Emission	MAGNUM and THOR ball valves

Why choose valve and actuator together
On board, how a valve performs also depends on how it is supplied, integrated and controlled. That is why it makes sense to consider the entire valve-actuator assembly, where OMAL’s approach delivers an advantage on three fronts.

The first concerns supply: valve and actuator are born in the same plant and arrive as a single group already sized, with the valve actuator coupling verified in production and no misalignment between body, gearbox and stem. For the shipyard and the system integrator this means a single technical reference, instead of components to coordinate across different suppliers.

The second is footprint. In the tight technical spaces on board, the lightweight MAGNUM and the KRAVEN butterfly valves keep weight and size down, while the AGO Handwheel actuator with integrated DANV handwheel removes a separate component and its connection kit, further reducing the footprint of the installed group.

The third is control. Where compressed air is not available — a frequent situation on board — the electric actuator EA IP68, on/off, integrates easily, with a protection rating suited to damp environments. Where air is available, the range is completed by the pneumatic actuator AGO, available in double acting and spring return and DNV certified.

Do you want to explore the complete range of valves and actuators for the marine & yacht sector? Click here and discover OMAL's certified solutions.

FAQ: Frequently asked questions about marine valves and actuators
Which valves are used for onboard fluid handling?
On board, ball valves and butterfly valves are mainly used. The former, such as MAGNUM and THOR, ensure reliable fluid shut-off; the KRAVEN butterfly valve is chosen for water lines and large-diameter circuits.
Electric or pneumatic automation for onboard systems?
It depends on the availability of compressed air. When it is missing, electric automation with the EA IP68 actuator is the simplest to integrate. The AGO pneumatic actuator, on the other hand, is a suitable solution when the system uses compressed air and when DNV certification is required.
Which certifications matter for marine valves and actuators?
The most important are the ship classification certifications: DNV, available on the AGO pneumatic actuator, and RINA, available on certain types of installation. Depending on the product family, Pressure Equipment (PED) CE/UKCA, the ATEX (Ex CE/UKCA) marking, SIL certification up to SIL3, the Fire Safe qualification and TA Luft & Fugitive Emission on the ball valves are added.
Which materials withstand the marine environment?
To resist corrosion, the marine valves are available in 316 stainless steel and, for butterfly valve discs, also in aluminium bronze. The actuators are made of aluminium, with special coatings (for example PTFE, nickel or zinc plating) for the most demanding conditions.
Which diameters do OMAL marine valves cover?
The MAGNUM ball valves cover DN 15 to DN 100, the THOR DN 15 to DN 200 and the KRAVEN butterfly valves DN 40 to DN 300, meeting both small circuits and larger-diameter water lines.