The unique DW Fuel Foot Valve System came into its own when a customer in Germany discovered a leak during bunkering. Within three hours, the pump had been taken apart and the service job was underway.
Svanehøj’s DW Fuel Pump is fitted with a unique foot valve system that makes it possible to perform a complete service of the entire pump – regardless of that tank’s contents and the liquid level inside the tank.
This unique feature was crucial when Svanehøj was recently called out to an offshore installation vessel in Germany.
The customer had discovered a leak in one of the ship’s DW Fuel Pumps during bunkering. However, by activating the foot valve system, Svanehøj’s service engineer was able to locate the fault and begin repairing the pump in just three hours.
“If the DW Fuel Pump had not been fitted with the foot valve system, the fuel tank would have to be emptied and rendered gas free prior to extraction. Instead of the three hours we spent prepping the pump for service, it could have taken days for us to prepare,” says Anders Jæger Thomsen, superintendent at Svanehøj.
There are several types of foot valve system on the market, but Svanehøj’s is among the most stable and reliable. This is because the feature is designed to utilise pressure from the fuel tank to keep the foot valve closed, as the surrounding pressure in the tank is higher than in the pump caisson.
The foot valve can be activated from outside the fuel tank. In case of a leak or other pump malfunction, the service engineer will add nitrogen to press out the LNG from the pump caisson through the foot valve. Afterwards, when the foot valve has been closed and the remaining gas vented off, the fuel pump is ready for extraction, whether this is for a full overhaul or minor service job.
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“We save 3-4 hours on every discharge operation”, says Fredrik Farsén, Technical Manager at Ektank AB, who is very happy with the investment in Svanehøj’s automatic super stripping system.
If a product/chemical tanker is equipped with a conventional stripping system, up to 20 litres of liquid cargo is left when the tank is stripped. If, however, the ship is equipped with Svanehøj’s integrated super stripping system, less than half a litre will be left in the tank. This reduces cargo waste to a minimum and means that the ship’s crew can avoid having to spend valuable time wash-ing the cargo tanks to get the ship ready for the next job.
The prospect of improving efficiency, saving costs and minimising operation time in port was the reason why, in 2018, Ektank AB chose to invest in Svanehøj’s super stripping system for the construction of the two product/chemical tankers EK Stream and EK River.
The system is more expensive than a traditional strip-ping system, but according to Technical Manager Fredrik Farsén at Ektank, the investment is worth every penny.
“All cargo being stripped is dis-charged ashore prior to departure. There are almost no remains on board (ROB) following the stripping operation. The stripping system can be managed by just one person, and we save 3-4 hours on every discharge operation compared to a conventional system”.
This is the first time that Ektank has installed Svanehøj’s super stripping system, but probably not the last. The system has met all expectations – and more.
“Compared to other vessels in the fleet, we avoid 2-3 cbm of ROB for every discharge operation”, says Fredrik Farsén.
Svanehøj’s super stripping system is installed as independent units in every cargo tank. A small vacuum tank is mounted in the cargo tank directly on the pipe stack of the deepwell pump and connected via pipes to a control unit (manual or automatic) on deck. This avoids containment of cargo, unlike other solutions on the market where the cargo is sucked into a central vacuum tank on deck.
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Svanehøj Group has realized sales of DKK 644.3 million in the first financial year since the divestment from Wärtsilä. Read our newsletter.
Proven technology and excellent support make SVANEHØJ a preferred partner for Wärtsilä Gas Solutions.
A newly developed containment system and vessel concept were brought to the LNG transportation marke
t when Saga Dawn, a 45,000-cbm LNG carrier, launched in the summer of 2019.
The patented system, called LNT A-BOX, has been developed by LNG New Technologies, who aim to open up the construction of mid-size LNG carriers to a wider range of shipyards.
Close dialogue throughout the process
SVANEHØJ has been involved in the project as a supplier of six DW Cargo (Gas) pumps, three DW Fuel (Spray) pumps and two DW Fuel (Marine) pumps – in close collaboration with Wärtsilä, who has been responsible for delivering the ship’s Cargo Handling System and Fuel Supply System.
According to Lars Nygaard from Wärtsilä Gas Solutions, the combination of proven technology and excellent support makes SVANEHØJ a preferred partner for new building projects such as Saga Dawn. And he emphasises the close dialogue between the parties throughout the process, from initial negotiation to delivery:
“With their experience, SVANEHØJ has been a good sparring partner in the sales phase, and they have helped us figure out which pumps would be best to use in relation to, for example, capacity and VFD. During gas trials, SVANEHØJ’s engineers were on-site to ensure that the pumps were started up and cooled down optimally. They were also ready to provide advice
to the control logic and use of VFD”– Lars Nygaard, product owner/advisor, Cargo Handling Systems, at Wärtsilä Gas Solution
Design with great benefits
Saga Dawn is one of the first ships to embark SVANEHØJ’s new DW Fuel (Marine) pump, built on the well-proven technology and design of the SVANEHØJ DW Cargo (Gas) pump. One of the major advantages of SVANEHØJ’s DW Fuel pump is that the electric motor is located outside of the fuel tank.
“It eliminates the excess heat and pressure, which may otherwise result in a significant energy loss when motors are located inside the fuel tank. At the same time, the pump is much faster and cheaper to install, and service and repairs can be carried out without emptying the tank,” says Jens Peter Lund, Sales Director, Asia, at SVANEHØJ. With the six SVANEHØJ DW Cargo (Gas) pumps onboard, Saga Dawn can
perform a full-load discharge within 15 hours. For Jens Peter Lund, the choice of SVANEHØJ’s electric DW pumps in the building of the Saga Dawn emphasises that shipyards have increasingly become aware of the advantages of the DW pump compared to a submerged pump:
“Our DW Cargo (Gas) pump handles all types of liquid gases at all temperatures and gravities. It is significantly less sensitive to impurities in the cargo. The motor is located on deck. This means there is no electrical installation or heat source below liquid level,” says Jens Peter Lund.
The electric DW Fuel (Marine) pump is designed for a five-year service interval. And can actually be serviced without gas-freeing the tank. The pump is individually controlled by 50–60 Hz frequency converters in stepless control of the pump’s rotational speed. This means the pump constantly adjust to the amount of fuel needed by the main engine, which reduces wear and tear of all systems components, as well as reducing the generator ratings onboard.
Saga Dawn has just completed its maiden voyage.
Nothing is left to chance when Samsung Heavy Industries (SHI) and Hyundai Heavy Industries (HHI) are building giant gas tankers worth billions of dollars.
In recent months, we have been conducting full-scale tests on the different types of gas pumps which SHI and HHI have ordered for six new VLEC’s. A total of 84 deepwell pumps, which amount to tens of millions of Danish kroner combined, will be shipped from Aalborg to South Korea.
The tests are being conducted in our 35-metre test tower, an unrivalled tool to validate how our deepwell pumps operate in the most extreme conditions.
– Our tower simulates the conditions onboard the ship. The pump is suspended in the tower, in the same way as in the tank, and during the four hours of testing, we measure the changes in temperature and vibration. For us, it is a facility of incredible importance, because we are able to demonstrate “robustness of design” so that customers can see for themselves that our pumps are as efficient and stable as we say they are, says project manager at SVANEHØJ, Lars Foged.
The story of the six new VLEC’s and our tests of deepwell pumps has been featured in several Danish and international media. Here are a few of the articles:
Korean Shipyards Test LNG Pumps in Denmark (English)
Verdens største værfter tester LNG-pumper i Nordjylland (Danish)