How KNF Pumps Ensure the Safety of LNG Propulsion on Ships

Revolutionizing Maritime Propulsion with LNG

In recent years, the maritime industry has seen a significant shift towards cleaner propulsion methods. LNG-powered ships are a major step forward, offering a low-emission alternative to traditional heavy fuel oil. Explosion-proof KNF diaphragm pumps are already installed in the gas control lines of some of today's LNG-powered ships to ensure the reliability of continuous leak testing.

Tighter Regulations for Seagoing Vessels Aim to Reduce Emissions

Most of the world's more than 90,000 seagoing vessels still rely primarily on heavy fuel oil, a byproduct of crude oil refining. Compared to land-based fuels, these viscous oils contain significantly higher levels of pollutants such as sulfur and heavy metals. Recognizing the importance of cleaner propulsion options, the shipping industry is actively pursuing stricter regulations through innovative solutions that increasingly prioritize environmental concerns.

A key regulation aimed at reducing sulfur emissions is the Sulfur Emission Control Area (SECA), which designates specific geographic regions where strict limits on sulfur emissions from ships are enforced. Another regulation focused on emissions control is the Decarbonization Emission Control Area (DECA), which targets greenhouse gas emissions, particularly carbon dioxide, from ships.

Navigating the Regulatory Landscape

Since January 2020, new regulations have extended beyond the more stringent SECAs and DECAs. These cover areas such as the North American coastline, the Baltic Sea and the North Sea, and require marine fuels to contain no more than 0.5% sulfur. Previously, the limit was set at 3.5%. As of March 2020, ships without special filters are not allowed to carry higher sulfur fuel in their tanks. In addition to reducing pollutant emissions, the Energy Efficiency Design Index (EEDI) requires new ships to have a carbon footprint below a certain benchmark.

The introduction of LNG-powered ships has set a new standard in the maritime industry. These ships, with their powerful new-generation engines, can run entirely on LNG at sea, resulting in the lowest possible emissions even when out of port.

Gas Control Systems Feature Explosion-Proof Diaphragm Pumps

To ensure reliable and safe operation of the integrated gas control system, the LNG supply and the controlled combustion processes for the large engines must be continuously monitored. For this reason, each safety module of the gas control system used is equipped with at least two diaphragm process pumps, such as the KNF N 680.1.2 Ex, which can be customized in close collaboration with the manufacturer of the supply system.

These modules are connected to an analysis unit that uses pressure and gas sensors to continuously monitor the air in the interstitial space of the double-walled gas pipe for traces of LNG. Even the smallest amounts of gas are reliably transported by the pumps so that any leaks can be detected immediately and appropriate action can be taken.

ATEX and Marine Certified Compliance

The flammable and explosive nature of LNG requires explosion-proof design of the systems used. Therefore, the KNF diaphragm pumps installed meet the ATEX specifications both internally and for the motor, making them suitable for use in potentially explosive atmospheres.
In addition, the pump motors meet all required marine certifications and the stainless-steel parts of the pump head are anodized to withstand the corrosive conditions of seawater. Typically, each gas control system is equipped with an identical second pump to ensure that reliable monitoring can be seamlessly bridged in the event of a unit failure.

KNF diaphragm pumps contribute to the overall integrity and effectiveness of LNG gas control systems by being clean, reliable and easy to maintain. By ensuring the quality of the media being handled, they provide a proven solution that improves system performance and longevity while reducing downtime costs.