Auto supplier cuts the cost of failure

Continual pump failure caused by abrasive slurry at an auto parts manufacturer was costing the company thousands of dollars a month in repair and replacement costs.


BJM Pumps KB Series pumps provided a cost-saving solution.

 

Dewatering pumps play a key part in the operation of an automotive supplier which manufactures die cast parts used to make power steering units distributed to several major car manufacturers in the United States and elsewhere.

Run in series within a duplex system, the pumps process coolant water after the machining process. This contains metal fines, or shavings, that completely saturate the water. Even though the metal fines are small in nature, the high ratio of fines to water creates an abrasive slurry and it was this that was causing extensive damage to the sump pumps’ mechanical seals, which resulted in pump failure.

When the primary pump had failed, the system had been switching operation over to the secondary backup pump. But by the time a new primary pump had been installed, the secondary pump had failed. This problem continued for several months and the constant turnover of pumps became costly to the manufacturer.

As a result it contacted distributor Premier Pump Co. to find out if there was a heavy duty submersible pump on the market that could operate more reliably for its specific application.

“This automotive manufacturer needed a durable dewatering sump pump that could process an abrasive slurry and they needed it fast,” said George T. Bennett, president of Premier Pump Co.

Premier Pump Co. was given a checklist of requirements for the pump. It had to be:
• Abrasive resistant – the new pumps had to be able to process water that was heavily saturated with metal fines. The new pumps’ internal components would need to withstand the abrasive slurry to reduce the possibility of pump failure and costly downtime.
• A proper fit – the new pumps had to be the right size to fit in the sump in addition to being easily installed and removed for maintenance. To avoid delays and increased maintenance expenses, the new pumps would need to feature a design that would allow them to be installed and removed quickly.
• Durable and reliable – the aim was to greatly reduce the amount of time and cost the auto manufacturer had been spending to pull the old pumps for inspection, maintenance and replacement.

Premier Pump Co. recommended the installation of two BJM KB75H submersible pumps in the sump system as they are designed for heavy duty dewatering applications and proven to pump fluids containing light slurry.

“After calculating the flow and head required the BJM pumps were selected because we knew they would work great in the application,” said Mr Bennett.

The BJM KB75H submersible pumps were chosen because of these key features:
• Abrasive resistant chrome iron components for durability.
• The KB75H utilizes a high-chrome agitator to keep solids suspended in liquid and help prevent the pump from clogging.
•A wear plate on the suction side acts as a replaceable hardened surface to counter the effects of erosion.
• A semi-open impeller effectively handles solids for optimal pump performance.
• Top discharge connection designed for efficiency.

Production of auto parts results in a high ratio of metal “fines” or shavings. As they are washed away, the fines in the water create an abrasive slurry.

 

The KB75H is a utility pump designed with a top discharge connection. For sump applications, the top discharge connection is ideal because a side discharge connection can break off or be damaged as it is pulled and pushed into place. Top discharge pumps are cooled by the pumped liquid. The KB75H pumps can pump a sump or pit down to within "inches" of the bottom. A side discharge pump without a cooling jacket must stay submerged to avoid overheating, leaving as much as 3 feet of slurry.

Every KB75H submersible pump model is protected by:
• Class H motor insulation, built in amperage (FLA), and temperature overload protection.
• Double mechanical seals of which the lower seal is made of silicon carbide and the upper seal, made of carbon/ceramic, is in a separate oil-filled seal chamber.
• A heavy duty lip seal which provides additional protection for the mechanical seals, helping to prevent abrasives from entering the seal chamber.
• A stainless steel shaft and shaft sleeve which minimizes shaft wear due to abrasives and, corrosion.

Once the automotive manufacturer approved the recommendation to use the BJM submersible pumps, Premier Pump Co. acted quickly to get a new sump pump installed at their facility. “We ordered the KB75H submersible pump on a Friday, arranged a courier to deliver the pump on Saturday morning, and had it installed and running Saturday afternoon,” said Mr Bennett.

“The automotive manufacturer installed a second KB75H in the duplex system and has a back-up pump on the shelf though they don’t expect to use it since the first pump has been running great for about 10 months and has not been pulled once.”