Constructed from high-grade 316L stainless steel, the portable unit integrates an efficient centrifugal impeller powered by a compact hydraulic motor. Capacity generally ranges from 70 to 150 m³/h against a head of 60–80 meters water column. Hydraulic drive power is delivered from the vessel’s central Hydraulic Power Pack (HPP)—typically installed in the engine room or forward equipment room—which feeds dedicated deck supply and return manifolds.

Fig. 1. Portable hydraulic submersible emergency cargo pump mounted within its tubular protective handling frame.

Fig. 2. Centrifugal pump casing, suction eye, and discharge connection prior to testing.

Testing Frequency, PMS Intervals, and SIRE 2.0 Compliance

Under the vessel’s Planned Maintenance System (PMS) and industry vetting programs such as OCIMF SIRE 2.0, the portable cargo pump, its dedicated hydraulic hoses, and trip valves must undergo physical operational testing at least once every six months.

During PSC inspections and terminal vetting reviews, auditors examine the physical equipment and statutory records listed under maritime ship certificates:

• Logbook confirmation and PMS work order closure of the 6-monthly operational run in fresh water.
• Visual condition of the flexible high-pressure hoses (absence of blistering, weathering, or outer jacket cracking).
• Valid hydrostatic test certificates confirming annual pressure testing to 1.5 times the maximum rated working pressure.
• Continuous electrical bonding continuity between coupling flanges and the pump chassis to prevent static sparks under international safety codes.

Fig. 3. Marflex manufacturer data plate displaying model designation, rated hydraulic pressure, and volume capacity.

Step-by-Step Testing Routine on a Marflex Hydraulic System

Prior to commencing, establish a formal job safety assessment using Marine Risk Assessment Online, conduct a toolbox meeting, and ensure all deck personnel wear full PPE (safety glasses, gloves, boots, and helmets).

Step 1. Deck Hydraulic Manifold Inspection

Locate the designated deck emergency hydraulic connection station. Verify that local isolation valves are closed and bleed any residual line pressure through the drain cock into a collection container before attempting to uncap the quick-connect couplings (QCC).

Fig. 4. Deck isolation valves supplying high-pressure hydraulic oil and return circuits.

Fig. 5. High-pressure supply and return valves isolated prior to hose hookup.

Fig. 6. Removing threaded stainless steel dust caps from the deck hydraulic connection ports.

Step 2. Inspecting and Preparing Hydraulic Hoses

Transport the dedicated hose reel to the test location. Inspect the coupling faces and rubber O-ring seals. Ensure both male and female coupling surfaces are clean; grit or particulate contamination entering the loop can cause internal scoring of hydraulic pumps and directional control valves.

Fig. 7. Inspecting quick-connect couplings and hose outer armor for integrity.

Step 3. Coupling Hoses to the Pump and Flow Control Valve

Connect the supply and return lines to the portable pump. Ensure the inline flow control valve / throttle unit is rigged correctly between supply and pump. Because supply (Pressure / IN) and return (Tank / OUT) ports feature different diameters, mismatched connections are mechanically prevented.

Fig. 8. Connecting hydraulic hoses to the pump’s portable flow control valve assembly.

Fig. 9. Manual flow regulator block used to control hydraulic fluid feed and pump impeller RPM.

Step 4. Connecting Hoses to Shipboard Deck Manifolds

Lay out hoses along the deck without sharp kinks or twists. Push the couplings firmly into the deck adapters until the lock balls snap home into the groove. Rotate the collar sleeve to prevent accidental unlocking under hydraulic surges.

Fig. 10. Aligning and engaging the quick-connect coupling into the deck receptacle.

Fig. 11. Rotating the outer sleeve collar to verify lock engagement.

Fig. 12. Supply and return flexible hoses firmly secured to the deck lines.

Fig. 13. Fully rigged test loop checked and ready for pressurization.

Step 5. Freshwater Drum Setup and Pump Submersion

Running mechanical seals without liquid causes rapid friction heat and seal face failure. Position a clean 200-liter drum on deck and fill with clean fresh water to a depth of 30–40 cm. Rotate the impeller by hand to ensure free rotation, then lower the pump into the drum using a certified hoist or three crew members. Crane movements must follow guidelines in Shipboard Crane Operator Safety.

Fig. 14. Pump submerged into the water drum with suction strainer fully immersed.

Step 6. Pressurizing the System and Water Circulation Trial

Start the hydraulic power pack in the auxiliary compartment and open deck isolation valves. System idling pressure will establish at 30–50 bar. Slowly crack open the manual throttling valve on deck. The impeller accelerates, creating continuous water circulation inside the barrel. Monitor for stable operation and confirm zero oil weeping from mechanical seals or quick-connect joints.

Fig. 15. Monitoring system operating pressure at the hydraulic power pack panel.

Fig. 16. Carefully adjusting flow rate to bring the pump up to operational test RPM.

Fig. 17. Discharge verification: water circulating smoothly at low RPM.

Fig. 18. Testing pump performance and verifying absence of abnormal shaft vibration.

Fig. 19. Satisfactory operational run: steady discharge head achieved with stable hydraulic return.

Post-Test Routine and Shipboard PMS Records

After operating the unit steadily for 5 to 10 minutes, gradually close the deck flow regulator, stop the hydraulic power pack, bleed remaining pressure, and disconnect the equipment:

• Drain the Volute: Lift the pump from the barrel and tilt the casing to drain internal water, preventing corrosion and winter freezing damage.
• Fit Dust Caps Immediately: Thread protective caps onto all hose and manifold quick-connect couplings. Marine salt spray on exposed sealing surfaces will ruin hydraulic valves.
• Fastener Check: Inspect and torque casing and bracket bolts. Ship vibration can loosen fasteners during storage.
• Safe Manual Handling: The portable unit weighs 60–80 kg, while armored hydraulic hoses are stiff and heavy. Use at least three crew members or a deck hoist.
• PMS Closeout: Complete the work order in the maintenance software (Amos, TM Master, Danaos) and record details in the Deck Logbook for vetting verification.

For broader tanker cargo operational planning, integrate pumping rates into Tanker Stowage Plan Software and review cargo handling procedures using the Bunkering Rate Calculator.