Pump technology for LNG
By Roberta Prandi14 April 2021
New submerged centrifugal pumps by Vanzetti Engineering for liquefied natural gas applications in the marine sector
Italy-based Vanzetti Engineering, a specialist in cryogenic equipment for liquified natural gas (LNG), has been working on liquid methane for marine applications since 2006 especially for what regards low-pressure LNG marine applications; in recent years, the company has also approached high-pressure LNG marine applications.
Recently, Vanzetti Engineering launched the new VT-3 reciprocating pump, designed and manufactured in compliance with marine classification standard. The VT-3 pump can be used as high-pressure pump to supply gas to MAN two-stroke ME-GI engines. It is available in a Triplex configuration with flow rate up to 14 m3/h and pressure up to 350 bar.
The VT-3 pump can also be mounted on skid (certified for marine applications as well) and provided with a range of accessories, including sensors, instruments and valves for safe and reliable pump control.
Vanzetti Engineering also offers the Artika series of submerged centrifugal pumps, whose models can be approved by the required marine classification. According to size (proportional to flow capacity) and number of stages (proportional to pressure), these pumps can be used as:
- Spray pumps or stripping pumps on LNG carriers and LNG bunkering vessels
- Main or backup pumps for feeding gas to low-pressure marine engines, with differential pressure up to 20 bar
- Small to medium cargo pumps
- Ship-to-ship bunkering pumps
- Floating storage regasification unit (FSRU) booster pumps, with differential pressure up to 55 bar
The pumps in the Artika series can be mounted on the bottom of LNG tanks or inside vacuum cryostats installed at the base of tanks. In both cases these pumps, equipped with bearings constantly lubricated with LNG and with no gaskets, preserve cold temperature conditions for quick and efficient start-stop operations and low maintenance.
Artika pumps are available in one stage or multistage configuration (2, 3, 4 or 6) and feature helical inducer to minimize requested net positive suction head (NPSH) and an integrated motor to be used with the inverter or variable frequency drive. According to Vanzetti Engineering, these pumps have a reduced noise emission, below 80 dB(A).
Artika submerged pumps can supply LNG at different flow and pressure rates. For instance, the bigger model Artika 300-2S can reach up to 300 m3/h flow rates with differential pressure up to 12 bar.
Both pump series - Artika and VT-3 - can be applied to all kinds of LNG-fuelled ships and are collecting a number of interesting references: for example, Vanzetti Engineering is the sole supplier of all cryogenic pumps of the Carnival Corporation cruise ships powered by LNG engines.
The company also supplied the fuel gas system pumps for the Royal Doeksen LNG catamaran ferries, with particularly low flow rate levels required. According to Vanzetti Engineering, in these applications, the Artika 120-3S model guarantees reliable and stable flow and pressure under all working conditions.
Container vessels such as the Wes Amelie (converted vessel) or the Nordic Hamburg (newbuilt) represent some of the many small-flow-rates applications for Artika pumps: in the first case for four-stroke engines, in the second one for two-stroke WinGD X-DF engines.
Vanzetti Engineering reported also that the first trans-Atlantic Post Panamax LNG Car Carriers to be built, owned and operated by Siem Car Carriers will be equipped with MAN two-stroke ME-GI engines and Vanzetti Engineering’s VT-3 pumps. Depending on the engine consumption requirements, the VT-3 pump can be tailored by Vanzetti’s engineers in Simplex, Duplex or Triplex configuration.