Amarinth Defies Space Constraints with Technical Breakthrough for Major LNG Expansion Project

Renowned for its engineering agility, Amarinth was approached to solve the complex technical challenges associated with in-ground hydrocarbon and solvent drain drum tanks, where traditional pumping solutions were deemed insufficient for the project's spatial and safety requirements.

The project centred on massive in-ground hydrocarbon drain drum tanks some 2 metres in diameter and up to 10 metres in length. To ensure the most cost-effective fabrication, the contractor required the upstands and downstands (the vertical sections where the pumps are housed) to be as small as possible.

Minimising this footprint was critical to reducing flange loading and material costs, but it left Amarinth’s engineers with a very little room for error. The pumps had to be slender enough to thread through horizontal piping during installation, yet powerful enough to maintain rigorous flow duties, with impeller diameters across the different tanks ranging from 235mm to 635mm.

With very tight deadlines, Amarinth couldn’t wait for the tanks to be completed to design the pumps and so worked closely with the fabricator during the tank design stages.

Amarinth’s engineering team utilised advanced computer modelling to design 5.5-metre-long API 685 magnetic drive vertical pumps that maintain a slim profile without sacrificing stability and require no external seal support system. Key innovations include:

• Vibration Control: To prevent resonance in the 5.5-meter shaft assembly, Amarinth optimised bearing spacing and design, ensuring the pumps remain within strict vibration tolerances even during the high-stress startup phase.
• Gulley Sucker Arrangement: Unlike standard pumps that leave sediment at the tank bottom, Amarinth’s unique design clears debris and dirty water from the very base of the downstand, protecting the long-term integrity of the system.
• Optimised Vantage Points: Due to access restrictions on-site, Amarinth designed a custom baseplate that aligns all vital gauges and instrumentation within a narrow, optimised viewing angle, allowing operators to monitor performance safely from a single vantage point.

The pumps have been designed to API 685 3rd edition specifications, ensuring hermetic containment of volatile fluids and eliminating the potential of fugitive emissions associated with traditional mechanical seals.

In-ground tanks are installed at an angle, typically requiring two different pump lengths for each end. However, identical pumps were required to simplify maintenance. Amarinth’s solution was a bespoke modular design that achieves complete interchangeability. This allows a single bare shaft pump to serve either position in the tank during maintenance, reducing the inventory costs and simplifying long-term servicing.

Recognising an aggressive project schedule, Amarinth will bypass traditional manufacturing bottlenecks, such as testing, using its split delivery methodology that it has developed with its supportive supply chain. Instead of waiting for the full order to be completed, where one small issue can delay everything, Amarinth will manufacture and deliver tested batches of pumps in parallel with the tank fabrication. This ensures that the moment a tank is completed, the pumps will be on-site and ready for installation.

"This project perfectly illustrates our engineering agility." said Oliver Brigginshaw, Managing Director at Amarinth. "By collaborating closely with the fabricator and rethinking the modularity of our API 685 VS4 magnetic drive pumps, we have designed a solution that isn't just technically superior, it’s more cost-effective and easier to maintain."