Liquid Gas Pump (LGP)
LGP (Liquid Gas Pump) is typically a centrifugal pump used for pumping liquefied hydrocarbons such as propane, butane, propylene and ethylene. These liquefied hydrocarbons are pumped at -104°C and Liquid Natural Gas (LNG) which is usually methane at -161°C and is the temperature at which they remain liquid as above this temperature the gases begin to boil and vaporise.
Due to the closeness of pumping temperature to boiling point low NPSH pumps are required. Inducers may be required to assist with low NPSH and immersed or submersible pumps used to ensure all liquid gas can be extracted from the container.
Magnetic couplings are the best sealing solution for such pumps as should the seal leak and the pump be exposed to atmospheric pressure the hydrocarbons will leak as a gas, which will not be visible, or noticeable due to lack of odour and poses a threat as an ignition source as well as health and safety.
Ships are increasing utilising LNG as a fuel as it can lead to a 21% reduction in ships emissions, helpful for compliance in Emission Control Areas (ECA zones).
