Metering pump, as the name suggests, is a type of pump which is used on a ship not only to transfer a liquid from one place to another but to supply it in a precise volume. Metering pump can be adjusted to provide different flow rates. They are generally used when the precision of volume to be delivered is very important.
The marine application of metering pump is in the form of chemical dosing pumps, which is used to transfer precise amount of dosing chemicals, especially in boilers. They are also used for dosing chemical additives to protect corrosion in the cooling water system. It is to note that the amount of dosing has to be precise. Overdosing or under-dosing may cause corrosion and other damages inside the boiler, which may end up in heavy repairs.
The metering pump is connected to the system in which the chemicals are injected with the help of valve in the pipeline. The pressure produced by this pump should be higher than the pressure in the pipeline, or else there will not be any dosing and the level of chemicals in the dosing tank will be the same.
The metering pumps consist of a small motor, which moves the plunger, in and out of the barrel, to provide pressure in the system. The check valves are provided in the suction and discharge side of the pump. A plunger type metering pump is a positive displacement pump and is suitable to use in a high-pressure system.
As this type of pump is frequently used to dispense concentrated and highly corrosive liquids, considerable care must be taken to ensure that the materials used in construction, particularly those of parts in direct contact with the liquid, are capable of resisting chemical reaction and corrosion.
Usually pump used is submerged lubrication oil pump for ship application. One of the components in the engine lubrication system is the oil pump. The oil pump is in charge of sucking and then distributing lubricant to the engine.
The DESLUBE series is a submerged lubrication oil pump for ship application deep well pump designed for Main Engine Lubrication oil supply for especially large two-stroke engines. The design is based on our long time experience of manufacturing deep-well pumps as well as the design features from our in-line centrifugal series. The pump is placed in the tank sump supported by dome flange and requires no further suspension. The sturdy construction ensures a reliable operation with low noice and vibrations level.
- Low NPSH
- Low noice or vibrations
- Low maintenance costs
- High reliability
- High flexibility
DESLUBE combine the advantage of good suction ability with the nature of the centrifugal pump to adopt the system pressure fluctuations. If the lube oil pressure is dropping, a DESLUBE pump will increase the flow to reduce the risk of severe damage and eventually break down on the main engine.
Submerged lubrication oil pump material specification
| Material combination | |
| Pump casing | Cast iron |
| Impeller | Bronze |
| Wear ring | Bronze |
| Discharge socket | Ducktile cast iron |
| Shaft | Carbon steel |
| Mech. shaft seal | Carbon/Ceramic |
Capacity range :
80 – 1000 m3/h
350 – 4400 US gpm
Head :
30 – 200 mlc
100 – 330 ft
MODULAR S – a theme in MODULAR construction
Irrespective of size and capacity the whole MODULAR S series is constructed of 5 standard components :
1. Pump casing
2. Impeller
3. Bearing housing
4. Suction cover
5. Shaft seal cover
The standardisation of these 5 components aids a minimum stockholding as some of the components are commom to the different pump sizes. Furthermore, this standardisation means low production costs from which you will benefit in the form of competitive prices. The pump casing is designed with a double, twisted flute which ensures efficient priming.
The impeller, which is closed, is manufactured with single curved blades and relief blades on the back. This leads to a
balancing of the hydraulic longitudinal forces, and therefore the pump accepts high rotational speeds.
Suction and pressure branches are designed as flange connections according to EN 1092 PN10/16 (~DIN 2501 PN10/16). A few of the small sizes have been designed with pipe thread branches.
The pump is fitted with mechanical shaft seal which has excellent wear qualities.
The direction of the flow is indicated by the arrows. To allow free passage of the air through the pressure pipe, ensure that valves, if any, are not closed during the priming.
The liquid circulation continues until the air has been removed from the suction pipe and the pump will then function as a normal centrifugal pump.
If for some reason, air penetrates into the suction pipe and the pump stops pumping, the priming process starts again as described above, and continues until normal pumping has been resumed.
Featured option – DESMI Modular S Super-primer
S70-50-175/A11 for quick priming
DESMI Modular S Super-primer is the right solution when quick priming is required.
The priming ability of the pump is up to 12,000 litres of air per hour, depending on suction lift.
This very fast priming is achieved by a combination of the diffuser principle and the liquid ring principle where a star wheel from the liquid ring pump is mounted on the same shaft as the impeller.
Up to ten times upgrade of priming ability
Read more : Modular S Centrifugal Pump For Marine
