Turning “bad actors” boiler-feed pumps to reliability

power generation
Customer Local Power major
Location India
Industry Power Generation
Key Services
  1. Inspection and analysis
  2. Repair and overhaul services
  3. OEM-X line
  4. Retrofit services

PUMPS REPAIRED & UPGRADED

3

MTBF IMPROVEMENT

3-5 years

PROJECT TURNAROUND

8 weeks

NUMBER OF PARTS RE-ENGINEERED

16

AGE OF PUMPS

>12 years

THE IMPACT

OEM-X line service-Comprehensive Pump services of the highest standards for any OEM from Sulzer ticks all boxes from quality, reliability, lead time and more, delivering a peace of mind for the power plant.

The Challenge

Three catastrophic failures send production into a downward spiral

  • For the power plant, one boiler feed pump failing is a problem. Three boiler feed pumps failing catastrophically, back to back? That was a real crisis.
  • The Chinese OEM pumps had complete rotor seizure, the extensive damage cause unexpected downtime and was eating into productivity.
  • Spares were utilized at a faster rate than replacement and any unexpected contingencies risked putting plant operations to a standstill.
  • The operator were eager to resolve this once and for all by getting an expert to identify the root-cause and solution.
  • As the power plant’s long-term partner and experts in the field, we were tasked to uncover the source of the issue.

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The Solution

Above and beyond boiler-feed pump repair

  • Our in-depth knowledge of boiler feed pump design for supercritical power plants was advantageous for the solution development turnaround.
  • A detailed failure analysis was done, by gathering data on the design and operations and 3 major issues were uncovered:
  • The stationary wear rings inside one of the pumps had seized badly onto the eye of the impeller.
  • The delivery cover was made of carbon steel, which is more vulnerable to corrosion than other materials like chrome steel.
  • The O-rings were also made of fluorocarbon compounds that weren’t design to operate in hot water, increasing the likelihood that they would swell or fracture and fail.
  • The pump design did not adequately consider the provision of the pump rotor vibration measurement

The retrofit comprised of:

  • Weld repair on delivery cover using high chrome steel overlay for quick turn-around while the delivery cover base material was upgraded to A182 (F-22 class 3) as long term solution. 
  • Design and implementation of shrink fitted impeller salvaging rings for the eye of the impeller. The rings design not only ensured repair option but also optimized material hardness and running clearances which lowered the risk of similar failures in future.
  • Chrome plating to shaft of the pumps to correct total shaft runout within the design and assembly limits for reliable operations.
  • Vibration monitoring instrumentation was incorporated to measure shaft vibration.
  • Engineers can take readings of the pumps’ rotor movements to catch potential problems before they spiral into total failures.
  • Reverse engineering was also carried out for other pumps within the plant for parts inventory replenishment.

Explore our solutions

  • oem_x_line_key_visual_1_final_1920w_x1280h
    OEM-X Line
    Outages and downtime are costly. Even worse, rotating machinery and pumps face numerous specific challenges, many of which are hard to isolate. Choosing the right supplier is vital when you factor in high maintenance levels and running costs of critical equipment.
  • Repair and overhaul services
    Repair services provide our customers with the assurance that when their piece of equipment is returned to operation they receive the maximum value from the repair process. No matter how complex the equipment, regardless of OEM, you can be confident your machine will perform as expected.
  • Inspection and Analysis
    Inspection and analysis
    Inspection and analysis provides you with the confidence of knowing the condition of your equipment. Maintenance and overhauls reduce the risk of failure and additional costs and knowing the condition of your equipment provides an opportunity for modifications to reach optimized performance levels.

The Customer Benefit

Productivity protected-now, and in the future

  • These critical assets weren’t just repaired; they were upgraded and optimized, with an expected life-extension of 15 years.
  • Spares supply will be adequately taken-care of with Sulzer’s robust global and local supply chain network.
  • Following this project, the company entered into a long-term customer service agreement with Sulzer, and plans to use Sulzer’s expertise to upgrade 18 pumps from five different OEMs, across five different power plants.
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