The sector may have experienced considerable M&A activity over the last two years, but the requirements for effective cargo pumps remain the same
Many of the companies making cargo pumps have been in business for decades. The design and technology changes little and the maturity of the product has seen owners look to divest and move onto other technologies.
In the tanker shipping world, the massive volume of cargo flows from tanker to shore or tanker to tanker have been traditionally handled by centrifugal pumps.
Proponents of screw pumps say their ability to handle a range of viscosities at various speeds make them an equally good, if better candidate for use in large tankers. The advantages of screw pumps are said to be:
Another advantage is that screw pumps achieve good line stripping without suffering vapour lock if entrained air enters the pump.
Ejectors are another proven technology for stripping lines and tanks. TeamTec chief marketing officer Olaf Evjen Olsen explained that the technology is relatively simple and robust. From the suction inlet, liquid is accelerated from approximately 2m/sec to 15m/sec and it can often contain foreign particles such as sand, rust scales and silt. All of TeamTec’s standard stripping ejectors that have a capacity of above 100 m3/h are made in Ni-Al-Bz, with a Monel nozzle, while smaller ejectors are made in bronze with an AISI 316 nozzle.
Bronze metal ejectors are said to be superior against cavitation and corrosion and in terms of general wear and tear. TeamTec can also deliver ejectors made entirely in stainless steel, or in super duplex materials for special installations on chemical or other tankers.
“Digitalisation is creeping into most systems and processes, and pump systems have not remained immune to this development”
US company Blackmer (part of PSG Dover group) has been in business since 1903 and is a proven manufacturer of screw pumps. The company has developed the S Series Twin Screw models specifically for the demands of ship unloading and product transfer to distant tank farms. The S series pumps have a compact design composed of two sets of opposed screws that engage during operation to form a sealed cavity with the surrounding pump casing. The pumped liquid is moved axially as the screw shafts turn, allowing the liquid to be steadily and constantly conveyed to the centre of the pump, where the discharge port is located.
Leistritz Pumpen of Germany has been building screw pumps since 1924. The current range of cargo pumps is of the “if it isn’t broken, don’t fix it variety”. The company offers three screw pump models for liquid cargoes accommodating viscosity from bitumen to diesel. The main features of the L2, L4 and L5 screw pump models are the low noise level and lack of pulsation of the liquid. The pumps are driven by electric motor, connected to a diesel engine or a hydraulic motor. The pumps are available in a wide range of casings depending on the liquids involved, including cast iron, aluminium or stainless-steel. The screw pumps can be installed on the tank top, submerged, or placed in a safe area via a gas-tight seal.
There is also a special version, the NT model (L2NT, L5NT) for use in submerged casings. The barrel removes the need for a pump room on the deck and provides an extra suction chamber, extending the suction beyond the typical seven to eight metre tank depth. Heating coils can be incorporated into the barrel and the stuffing box for pumping high viscosity liquids like asphalt.
Innovations such as a smaller footprint for the pumping equipment or the lack pf pump room are attractive to some operators, but the centrifugal pump is still the popular choice for a wide range of pumping activity on a tanker.
A typical application is to pump seawater to cool the engine. The seawater cooling system on a ship is controlled by centrifugal pumps that send ambient seawater in a circulating loop into a heat exchanger with the vessel’s freshwater cooling system. The freshwater cooling system cools the engines, generators, other cooling loops and auxiliary equipment that consume significant amounts of energy. Seawater that has taken on heat from fresh water is then pumped back into the ocean as cooler ambient seawater is drawn in. This continuous operation is vital to the ship’s operation.
Digitalisation is creeping into most systems and processes, and pump systems have not remained immune to this development. The Colfax Fluid Handling’s CM-1000 series allows seawater cooling system pumps to operate at variable speed for energy savings, while its active valve control (AVC) feature limits the risk of pump cavitation and delivers additional savings by adjusting the duty point for optimal operation. Its condition monitoring and operation monitoring features provide maintenance savings by preventing catastrophic breakdowns and increasing mean time between failures.
Pompe Garbarino S.p.A of Italy has a close relationship with the Fincantieri shipyard and is supplier of centrifugal and positive displacement pumps for vessels under construction in the yard. The company is also a pump supplier to scrubber manufacturers Wärtsilä and to Alfa Laval.
Alfa Laval purchased Frank Mohn AS and the Framo brand in 2017. This year the Framo subsidiary won a contract worth approximately Skr70M (US$7.8M) to supply a pumping system for a floating production, storage and offloading (FPSO) vessel that will be built in China.
The order includes marine pumping systems for crude oil offloading, slop, produced water, off-spec oil and ballast pump duties.
This is the fourth FPSO pumping system order Framo has reported in recent months: in April, it announced a contract for an FPSO vessel in the North Sea, worth Skr125M, and another contract for an FPSO vessel to be built in China, with a value of Skr70M. In June, a further contract for another North Sea FPSO was announced, worth Skr65M.
The second marine pump divestment involved the sale of the fluid handling division of Colfax to Circor International for a reported US$860M. Commenting on the sale, Colfax president and chief executive officer Matt Trerotola said: "Over the past two years, we drove a step change in the Fluid Handling business and, after thorough review, determined that combining it now with Circor is in the best interests of the business, its associates, and the shareholders of Colfax Corporation."
Circor supplies both centrifugal and screw pump types, but for tanker cargo operations and transfers, it recommends three screw pumps. The Circor Allweiler (< 5‚300 m3/h) and IMO (up to 54 m3/h) three-screw pumps are rotary‚ self-priming positive displacement pumps. The pumping elements consist of three moving parts: the power rotor (main screw) and two symmetrically opposed idler rotors‚ all operating within close fitting housing bores.
The incoming process fluid is conveyed by the rotating power rotor by means of the cavity formed with the intermeshing idler rotors. These two hydraulically-driven shafts‚ which only make rolling contact with the power rotor‚ regulate the amount of internal slip. From suction to discharge, the fluid is transferred by means of a series of constantly forming and re-forming chambers until it reaches the casing outlet.
Symmetrical pressure loading on the power rotor eliminates the need for radial bearings to absorb radial forces. The idler rotors generate a hydrodynamic film which provides radial support similar to journal bearings. Axial loads on the power rotor and idler rotors‚ created by differential pressure‚ are hydrostatically balanced. By this design arrangement high differential pressures can be managed. To achieve higher flow rates‚ double ended or double suction three-screw pumps can be applied‚ with the flow pattern being the same as a two-screw pump.
Also in 2018, Taiko Holdings of Japan took a further stake in MarFlex Holding, resulting Taiko Holdings becoming the 100% shareholder of MarFlex Holding. As a result of this acquisition, Taiko Holdings has also become the 100% shareholder of Snijders, which has been a part of MarFlex Holding since 1 January 2016.
Taiko is one of the larger pump manufacturers in Japan and a well-known player in the Far East. Over the last 37 years, MarFlex has built up a worldwide name and brand reputation in the field of electrically-driven deep-well pumps, while Snijders designs and produces automation solutions for the maritime, offshore and dredging sectors.
In early 2019, MarFlex achieved a special milestone when Dutch shipyard and engine supplier Dolderman, active in the inland shipping market, ordered its 400th MarFlex deep-well cargo pump. MarFlex has been working closely with Dolderman for the last 10 years.
Another big acquisition in this sector in 2018 was the Kongsberg group of Norway agreement to buy Rolls-Royce’s commercial marine business for an enterprise value of £500M (US$662M). The purchase included the propulsion, deck machinery, automation and control and smart shipping technology divisions of Rolls-Royce’s portfolio. Kongsberg has a presence in the pump market through its link-up with Consultas, which has resulted in a range of products and system solutions in the loading computer arena.
K-Load is Kongsberg’s 3-D system. It utilises a 3-D hydrostatic model of a vessel – providing a full geometric definition – as the basis for the calculation of loading conditions, floating position and stability, and longitudinal strength. This creates a precise description of the actual loading conditions, dispensing with the need to rely on pre-computed tables, simplifications or assumptions. The result in no dead freight or overload. By utilising the full geometrical definition of the vessel as the basis for the computation, additional applications have been developed to improve load planning and condition handling. These include applications relating to water ballast distribution, water ballast exchange, damage stability, pumping among other systems. The applications are digital and can be linked together to create a maritime digitalisation environment. The K-Load solution is type-approved by DNV and Lloyd’s Register, ensuring the quality of the product and the calculated results it delivers.
The latest pump company to be divested from its parent is the Aalborg, Denmark-based pump manufacturer Svanehøj Group. It is optimistic about going it alone following its divestment from Wärtsilä, which was announced in October 2018.
Svanehøj was acquired by Copenhagen-based investment house Solix, which has committed to support the deep well and in-line pump specialist by strengthening its sales and servicing arm and investing in new production development.
“Even though we have been very pleased being a part of the Wärtsilä family, we are confident that we will also benefit positively from the transfer to Solix,” says Svanehøj’s sales director Jens Peter Lund.