Relatively few large new refineries have been opened over the past decade. The average age of existing facilities is about 40 years and some are far older. Hence, maintenance and repair services are more crucial than ever. Operational efficiency, refinery output, worker safety, and environmental compliance all suffer as wear and tear set in.
Within any refinery, there are hundreds and sometimes thousands of pumps in operation. One failure can bring the facility to a halt. Unfortunately, some pumps are left running for decades with scant attention paid to the state of their key components. Therefore, it is recommended that mission-critical pumps receive thorough, regular inspections and are sent in for refurbishment periodically.
The goal of the pump repair shop is to ensure longevity and efficiency. This leads to peace of mind for refinery engineers, responsible for minimising downtime. One pump repair company details the steps of its thorough inspection and refurbishment of a critical 12-stage centrifugal pump at a Canadian refinery. Reliable parts, spare parts retention, balancing, wear measurement, and testing are the hallmarks of its process, all the while adhering to a quick turnaround.
Maintaining refinery reliability
The lubricants centre in Canada has a production capacity of up to 15 600 bpd. The facility produces automotive, industrial, and food-grade lubricants, alongside greases, base oils, process oils, and specialty fluids. It is one the largest manufacturers of high-quality Group III base oils in North America and its products are exported to more than 80 countries.
The refinery originally purchased a centrifugal pump from ClydeUnion Pumps (a Celeros Flow Technology brand) approximately 20 years ago. This pump lay at the heart of hydrocracking and lubricant operations. Celeros FT supplies the facility with aftermarket services, using its own engineers and validated service partners, depending on the location of the installation. The parts that the company supply meet the original specifications or are upgraded where appropriate. Some components are covered by a ‘rapid response’ option, which means they can be delivered to a customer site within 24 hours.
This 12-stage pump sent in for refurbishment operates inside the lube oil refinery at an average temperature of 150°F, with a peak of 175°F. This CUP-BB3 pump is a heavy duty, axially split-case horizontal machine with opposing impellers with a single suction first stage impeller. These pumps comply with the latest edition of API 610 and API 682 standards and are specifically designed for heavy duty, medium, and high-pressure applications. A flexible configuration allows it to function across a range of duties varying from standard water, oil, and chemical applications to advanced water flood and boiler feed applications.
Although the unit continued to operate reliably as part of overall plant operations, its efficiency had decreased and it showed signs of wear and tear. The refinery contacted ClydeUnion Pumps and arranged for it to be shipped to the shop for inspection, rebuild, and testing.
The work scope included disassembly, cleaning, and inspection. This revealed the need for new bearings, oil rings and associated hardware, bearing isolators, mechanical seals, throat bushings, compensator bushing, centre bushing, and a new split line case gasket, as well as removing and installing oversized impeller rings to achieve the correct clearance. In addition, the rotor needed to be rebalanced, axially positioned, reassembled, mechanical seals torqued correctly, painted, and returned to the refinery. Shaft alignment at the drive end was taken to a tolerance of less than 0.001.
An air test of the mechanical seals was successfully conducted at 25 psig for 30 min. In addition, a liquid penetrant inspection was completed on existing weld connections of the casing drains.
To ensure long life, the shop recommended that spares of certain parts be purchased and retained onsite. These components could be switched out in the field and would avoid the need to return the pump to the shop. This included inner and outer bearing isolators, radial and thrust bearings, and oil rings.
The refinery’s reliability engineer commented that he was impressed that ClydeUnion could rebuild, test, and return this pump to service in only one week.
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