Improved production at tank terminal
with notos screw pump case study 

THE APPLICATION

A major oil company operates a significant terminal at a major port that loads and unloads tanker vessels. The operators were having problems with the two centrifugal pumps they were using to transfer fuel for two different operations. Transferring fuel from terminal bunkers to tanker trucks and rail cars was one application. The second application involved the delivery of bunker fuel to ships. Cavitation was causing the customer's centrifugal pumps to fail. The system had a low NPSHa due to the viscosity of the fuels, which varied with temperature. To get the centrifugal pumps to work properly in these applications, diesel fuel was mixed with the other fuels to reduce viscosity. According to the customer, about 800 gallons (3.03 m3/day) of diesel fuel had to be injected into the process per day, at a cost of about 2,000 USD/day.

THE neTZSCH NOTOS solution

When the customer discovered that NETZSCH had experience with this type of application and that they could use a single pump to eliminate the need for product mixing, they contacted NETZSCH to discuss a solution. It was then suggested that a NOTOS® twin screw pump, model 4NS1830/40H5E, be used. Several factors were considered when refining the multiple screw pump features. For example, the viscosity of the fuels combined with the pump operating speed necessitated the use of an API 682 double cartridge seal with an API 54 seal flush plan. To recirculate the seal barrier fluid and ensure leak-free service, a NOTOS® model 2NS pump was chosen. The customer noticed a drastic improvement in production as well as savings of $2,000/day because they no longer needed to mix diesel fuel into the HFO to reduce the viscosity.