Why the FA1D67-02-03 Radial Bearing is the Lifeline of Booster Pump?

The booster pump stands as the power outpost in the power plant's boiler feed system, responsible for pressurizing deaerator water before it hits the main feed pump. The FA1D67-02-03 Radial Bearing is the main support column for this outpost's entire shaft line. It is unassuming, yet it bears all the radial load of the spinning pump shaft and holds the key to rotational precision.

The fact that power plants designate this bearing as a safety insurance item during scheduled maintenance—to be checked closely and replaced when necessary—is never over-maintenance. It is because performance decay in this specific bearing harbors the severe risk of booster pump shutdown and feedwater interruption. Overlooking even an inch of wear can lay the groundwork for an unplanned outage.

I. The Load-Bearing Core: When It Fails, the Whole System Collapses

In the FA1D67 booster pump shaft assembly, the FA1D67-02-03 radial bearings sit inside the bearing housings at both ends of the pump body, acting like two steady hands firmly supporting the pump shaft. Their core role is to absorb all the radial forces generated when the shaft and impeller rotate (e.g., reactive forces from media hitting the impeller, shaft imbalance). This prevents the pump shaft from wobbling and the impeller from running off-center.

The pump shaft spins quite fast, making several revolutions per second. Without these steady hands, the shaft would oscillate radially like an uncontrolled gyroscope. If that oscillation exceeds even 0.03mm, the impeller edge will start scraping the inner wall of the pump casing. The grating sound of metal friction is only the start; soon, grooves form on the impeller, pump discharge plummets, and the entire booster pump begins to resonate dangerously.

Crucially, this steady hand also manages lubrication. The bearing's inner bore features a thin silver plating (5-10µm thick) to minimize friction. Coupled with a precise clearance of 0.02-0.05mm, lubricating oil forms a stable film within this gap, achieving fluid lubrication. The shaft journal never directly contacts the bearing surface, ensuring wear is naturally slow. If bearing wear causes the clearance to widen, the oil film collapses. Dry friction causes the temperature to spike instantly, leading to the bearing welding itself to the shaft in minutes—the classic bearing failure or wiped bearing.

One plant tried to run on a worn bearing, only to have the booster pump trip on excessive vibration less than a week later. Disassembly revealed grooves 0.1mm deep in the bearing bore and severe scoring on the pump shaft journal. The cost of repairing the shaft journal and replacing the bearing was three times that of a regular scheduled replacement. If your booster pump vibration levels are slowly creeping up, check the radial bearing clearance before checking the impeller—it's likely bearing wear. You can contact our technical team to bring testing tools on-site.

II. The Chain Reaction of Bearing Failure: A Safety Minefield for the Plant

Calling the FA1D67-02-03 radial bearing safety insurance is warranted because its failure triggers a sequence of catastrophic issues, moving from simple equipment failure directly to plant safety risks.

The most immediate result is excessive vibration. Once the bearing wears, the shaft's radial runout exceeds the limit, and the booster pump's vibration level skyrockets from a normal below 2.8mm/s to over 5mm/s. This vibration travels down the piping to the main feed pump, causing its bearings to suffer and potentially triggering a main feed pump mechanical seal leak. Two otherwise independent machines are dragged under by the failure of a single bearing.

Next is sealing system collapse. The booster pump's mechanical seal relies on the precise fit of the rotating and stationary rings. The concentricity required for this fit is entirely dependent on the radial bearing support. If the bearing wobbles, the rotating ring swings with the shaft, creating a gap between the sealing faces, and high-pressure media sprays out. This leak not only pollutes the area and wastes demineralized water but also accelerates wear on the sealing face due to lack of lubrication, creating a vicious cycle of leak more, wear more; wear more, leak more.

The most serious outcome is cascading shutdown. The booster pump is the feed pump's pre-pressurization stage. If the bearing seizes, the booster pump trips immediately. If the standby booster pump fails to kick in swiftly, the main feed pump's inlet pressure drops instantly, triggering a low-pressure protection trip. With the feed pump stopped, boiler water supply is cut off, and drum level drops fast. Operators must rapidly reduce load or even execute an emergency shutdown—this chain reaction costs not only power generation but also significant equipment repair expenses.

III. Bearing and Associated Component Synergy: No Single Part Stands Alone

The radial bearing is not fighting solo. It forms a support-seal-lubrication system with the pump shaft, impeller, and oil deflectors. A problem with any of these components compromises the bearing's insurance function. The main focus on the bearing during maintenance is essentially a check on the entire system's stability.

Below are the core components closely associated with the FA1D67-02-03 radial bearing in the FA1D67 booster pump that must be inspected concurrently:

For example, if the pump shaft journal is worn, the fit clearance is enlarged even with a new bearing, and the bearing cannot control radial runout effectively. If the oil deflector deforms, lube oil leaks out, and the bearing, deprived of oil, wears rapidly. Therefore, maintenance must check all these associated parts—but the bearing remains the system's core pivot point, and its condition dictates whether the function of all other parts can be realized. This is why it is prioritized.

IV. Mandatory Scheduled Replacement: It's Risk Avoidance, Not Waste

Some plants think, If the bearing isn't broken, don't replace it. This mindset overlooks hidden degradation. Performance loss is gradual; by the time obvious failure occurs, it has usually caused other, more severe problems. Checking the bearing closely and replacing it when necessary during scheduled maintenance is the most economical risk avoidance measure.

The core of a good check is looking for that unseen decay: check for peeling of the silver plating in the bearing bore—the silver layer prevents corrosion and reduces friction; if more than 20% is gone, corrosion and wear rates double. Check if the fit clearance has exceeded 0.05mm—larger clearance destabilizes the oil film, drastically increasing dry friction risk. Check for subtle scorch marks on the bearing surface—a signal of localized overheating, indicating a lubrication problem.

Even if these indicators haven't reached the failure threshold, replacement should occur if they are near the limit. For instance, one plant measured a bearing clearance of 0.048mm, just below the 0.05mm limit, but still replaced it during the overhaul. The unit was entering a high-load operation period, bearing load would be high, and any slight further increase in clearance could trigger failure. Later estimates showed the bearing replacement cost a few thousand dollars but avoided potential outage losses of tens of thousands.