1. Core Pain Points of Bearing Replacement in Water & Wastewater Treatment

The water and wastewater treatment industry is the infrastructure lifeline for urban operation and the ecological environment. Municipal wastewater treatment plants, industrial effluent treatment stations and water supply plants require long-term uninterrupted continuous operation. Critical equipment such as lift pumps, aerators, clarifiers, sludge dewatering and conveyors operate year-round under extreme conditions of high humidity, corrosive gases (hydrogen sulfide, chlorine), sewage immersion and fiber entanglement.

 

Compounding the challenge – a large portion of treatment plant equipment is located in confined, hard-to-reach locations such as underground pump rooms, tank bottoms and shafts. Traditional solid bearing replacement requires disassembly of shafts, couplings, gearboxes and numerous surrounding components – which are often wrapped in sewage and sludge, making disassembly extremely difficult. At United Utilities‘ Widnes water treatment plant in the UK, replacing solid support bearings required hiring an 80-foot reach crane at a cost exceeding £2,500 per day. At Wessex Water‘s aerator application, during periods of heavy rain the sludge level in aerator tanks rose to the point where bearing units became temporarily submerged, compromising seals and leading to premature bearing failure. A large wastewater treatment plant in the northeastern US uses 96 RBCs with ineffective sealing systems that fail to prevent contamination. Bearing mud intrusion and frequent replacement is a common phenomenon in treatment plants.

 

Typical pain points of traditional solid bearings in water treatment:

 

Inaccessible equipment locations – Lift pumps are at the bottom of pump rooms or underground; clarifiers are on central drive bridges above sedimentation tanks; aerators are several meters above aeration tank surfaces. In these locations, lifting equipment cannot access, and maintenance personnel working space is extremely limited. The advantage of split bearings is especially valuable in hard-to-reach or trapped places.

 

Sewage and corrosive environments – Treatment plant equipment is long-term exposed to sewage, sludge, corrosive gases and humid conditions. Corrosion is not a cosmetic issue – it directly degrades bearing performance and reliability, with pitting and micro-spalling on raceways increasing friction and operating temperature.

 

Fiber entanglement and contamination – Fibers, hair and fabric debris in sewage wrap around bearings and seals, causing seal failure and bearing seizure. Fibers and sludge residues settle in gaps, increasing current consumption and eventually damaging motors.

 

Enormous disassembly workload – Replacing one bearing requires disassembling couplings, motors, gearboxes, frames and numerous surrounding components. United Utilities required an 80-foot crane to remove solid support bearings at over £2,500 per day. Seal failures occurred 4 times per year, each consuming 3 days – 12 days of unplanned maintenance annually, costing an estimated €15,780 plus €1,541 per year in engineering support.

 

Downtime causes compliance risks – Unplanned downtime at wastewater treatment plants may cause sewage overflow and excessive emissions, facing huge environmental penalties and criminal prosecution risks. Thames Water‘s picket fence support bearing failed and required expert emergency assistance.

 

Short service life of traditional bearings – Treatment plant equipment is in constant direct contact with sewage and sludge. Corrosive media penetration, high humidity and frequent start-stop impact mean conventional solid bearings typically last only 6-12 months, with extremely high replacement frequency. A mixing screw conveyor installed in 2013, overhauled in 2014, began leaking sludge in 2015 – replacement every 3 months still failed to stop leakage.

 

2. NMT Split Bearings for Water Treatment: No-Shaft-Removal Quick Replacement

NMT split bearings for water treatment perfectly combine the core advantage of split bearings – “no-shaft-removal installation“ – with the special requirements of treatment plant equipment. The inner ring, outer ring, rolling elements and cage are all split along the axial direction – installation requires no removal of shafts, couplings, gearboxes or any other core components – assembly is completed directly on the shaft in situ.

 

More critically – NMT split bearings can be replaced without removing drive motors, couplings, piping, without moving shaft systems, without using large lifting equipment. Installation requires no movement of surrounding equipment or machinery – installation costs are low, replacement is convenient, and downtime is reduced. This is like installing a “service door“ on treatment plant equipment, enabling true “online“ maintenance.

 

▸ Full Split + Corrosion-Resistant Construction: Every Piece Can “Go in Separately, Rotate Together“ – Withstanding Sewage Corrosion

 

Every component of an NMT split bearing for water treatment is split – split inner ring, split outer ring, split cage with rolling elements, split seals. During installation, these half-ring components are assembled sequentially around the shaft. After being locked with high-strength stainless steel bolts, they form a precision transmission unit with performance fully equivalent to a solid bearing. Split bearings disassemble into smaller components, easing lifting and handling tasks and making assembly or changeout simple even in the most cramped and inaccessible conditions.

 

In terms of materials, NMT offers a complete corrosion-resistant steel system for treatment plant high-humidity, corrosive environments – bearing steel with special anti-corrosion surface treatment resists sewage and corrosive gas attack; all-stainless steel (304/316L) is suitable for highly corrosive environments, with a self-repairing passive film. For fiber entanglement in sewage, split bearings feature smooth surface design and optimized sealing structures to reduce fiber adhesion and wrapping.

 

▸ No-Shaft-Removal Installation: No Motor Removal, No Piping Removal, No Large Lifting Equipment

 

The core value of NMT split bearings for water treatment is – bearing replacement without moving the shaft, without removing motors and couplings, without removing inlet/outlet piping, without using large lifting equipment. This means for lift pump bearing replacement, the motor stays in place, couplings stay in place, piping stays in place, the pump body stays in place. United Utilities‘ experience proves that with split bearings, the £2,500/day 80-foot crane is no longer needed. Maintenance personnel simply open the bearing housing, remove the old bearing halves, install the new bearing halves, and tighten the bolts – complete.

 

▸ Interchangeable with Standard Heavy-Duty Solid Bearings

 

NMT split bearings for water treatment are designed with full interchangeability with standard heavy-duty solid bearings in mind. In most cases, the outer diameter and outer ring width of split bearings are identical to standard spherical roller bearings (222, 230, 231, 239, 240, 241 series). Split bearings can often directly replace a standard spherical bearing in an existing housed bearing housing without any machining modifications.

 

3. Product Series

NMT offers a complete split bearing product system covering multiple treatment plant applications:

 

▸ Lift Pump Split Spherical Roller Bearings

 

Lift pumps are the “heart“ of wastewater treatment plants – their bearings are long-term immersed in sewage, enduring heavy loads and corrosion. A large sludge pump crankshaft at United Utilities‘ Oldham wastewater treatment plant uses split roller bearings for heavy-duty support. NMT split spherical roller bearings are specifically designed for lift pumps, sludge pumps and other heavy-load corrosive applications – inner rings, outer rings and cages with rollers are all split in half. Spherical outer ring raceways and barrel-shaped rollers provide self-aligning capability, effectively compensating for shaft deflection.

 

▸ Aerator Split Bearings

 

Aerators are critical for oxygen supply in treatment plant biological tanks – their bearings are long-term exposed to water surface and sludge splash. Wessex Water aerators were submerged during heavy rain, compromising seals and causing premature bearing failure. NMT split bearings enable bearing replacement without removing aerator discs or main shafts. When Pingtan Environmental‘s aerator disc end bearing failed, maintenance teams completed precision cutting, removal and installation in complex conditions.

 

▸ Clarifier and Sedimentation Tank Split Bearings

 

Clarifier and sedimentation tank drive bridge bearings are located in the center of tanks – hard-to-reach positions. Thames Water‘s picket fence support bearing failed and required expert emergency assistance. NMT split bearings enable bearing replacement without removing clarifier bridges or drive units.

 

▸ Sludge Dewatering and Conveying Equipment Split Bearings

 

Sludge dewatering and conveying equipment is long-term in contact with highly abrasive sludge and fibrous contaminants. A mixing screw conveyor required bearing replacement every 3 months. NMT split bearings with multi-seal and wear-resistant designs effectively resist sludge and fiber attack.

 

▸ Split Housed Bearing Units

 

NMT offers split housed bearing units that integrate split bearings and housings as a complete assembly. The core advantage is “radial installation and disassembly“ – no need to disconnect and disassemble components around the bearing such as motors, gearboxes and couplings. The housing can swivel around the shaft, ensuring that the seals always remain concentric to the shaft, thus effectively excluding contaminants. United Utilities‘ experience proves split housed bearing units significantly reduce downtime for treatment plant equipment.

 

4. Specialized Sealing and Lubrication Systems

Treatment plant equipment operates year-round under harsh conditions of high humidity, corrosive gases, sewage immersion and fiber entanglement. NMT split bearings for water treatment feature customized sealing and lubrication systems:

 

▸ Multi-Barrier Sealing – For high-contamination treatment plant environments, NMT provides a multi-barrier sealing solution. The first barrier is the precision-machined seal itself, the second is a V-ring seal mounted directly on the bearing, and the third is grease surrounding the bearing. This multi-layer protection effectively excludes contaminants, further extending bearing service life.

 

▸ Fiber-Entanglement-Resistant Design – For fibers, hair and fabric debris in sewage, NMT split bearings feature optimized seal lip design and smooth outer surfaces, reducing fiber attachment points and preventing fiber accumulation that causes seal failure and bearing seizure.

 

▸ Split Seals – Seals are also split for installation without shaft threading, assembled simultaneously with the bearing.

 

▸ Corrosion-Resistant Grease – NMT offers graded lubrication solutions: standard conditions use water-resistant extreme-pressure heavy-duty grease; high-corrosion conditions use chemical-resistant grease. The grease offers excellent water washout resistance and rust protection, maintaining stable lubricating performance in sewage environments.

 

5. Installation Efficiency Comparison

Traditional solid bearing: Shutdown → drain pump chamber/tank water → disconnect inlet/outlet piping → disassemble motors, couplings, gearboxes → move shaft → slide bearing on → realign → reassemble → refill water. Time: days to weeks.

 

NMT split bearing: Shutdown → open housing → remove old halves → install new halves → tighten bolts → complete. Time: just hours.

 

Water Treatment Industry Specific Data:

 

United Utilities (UK) : Widnes water treatment plant solid support bearing replacement required an 80-foot crane at over £2,500 per day. With split bearings, no crane is needed – significant cost savings.

 

Seal Failure Maintenance Costs: Large treatment plant pump seal failures occurred 4 times per year, each consuming 3 days – 12 days of unplanned maintenance annually, costing an estimated €15,780 plus €1,541 per year in engineering support.

 

Centrifugal Pump Bearing Replacement: An 8-stage centrifugal pump bearing at a treatment plant was replaced in a very short time, preventing weeks of unplanned downtime and thousands of euros in equipment damage.

 

6. Quality Control

NMT implements a strict quality control system for water treatment split bearings:

 

Corrosion-resistant material certification – Each batch of bearing steel undergoes salt spray corrosion testing and material composition analysis to ensure performance meets treatment plant high-humidity, corrosive environment requirements

 

Precision split surface machining – High-precision wire cutting for inner and outer ring split surfaces, ensuring concentricity and strength after assembly

 

High-strength stainless steel locking system – Stainless steel clamp rings and multiple bolts ensure split surfaces remain secure during operation

 

Seal performance verification – Each batch undergoes sewage environment seal testing to ensure sealing effectiveness under high-humidity, corrosive treatment plant conditions

 

Post-assembly precision inspection – Each split bearing is inspected for radial clearance, rotational accuracy and vibration after assembly – ensuring performance equivalent to solid bearings

 

7. Stock Availability & Customization

Common split spherical roller bearings and split cylindrical roller bearings kept in stock – covering over 80% of split bearing needs for lift pumps, aerators, clarifiers, sludge dewatering, conveyors and other treatment plant equipment. Emergency failures receive rapid response – minimizing unplanned downtime.

 

Treatment plants commonly use shaft diameters up to 200mm+. Pre-stocking split bearing spares can dramatically shorten emergency downtime.

 

Custom solutions available: special bore/OD/width (standard range 55mm to 630mm, expandable), custom corrosion-resistant materials (stainless steel/special anti-corrosion steel), special split configurations, custom sealing solutions (fiber-resistant/fully submerged seals), custom clearance, split housed bearing units.

 

Rapid customization from samples or drawings. Cost-effective replacement for imported brands (SKF Cooper, FAG, Timken, NSK) with significant procurement savings.

 

8. Lifecycle Cost Optimization

Unplanned downtime of water treatment facilities loses not only equipment repair costs but also penalty fines for excessive emissions, environmental remediation costs, government accountability and corporate reputation damage. Thames Water‘s picket fence bearing failure required expert emergency assistance. United Utilities‘ Widnes plant traditional solution required an £2,500/day 80-foot crane. The large northeastern US treatment plant‘s 96 RBCs suffered frequent maintenance from seal failure.

 

Hidden costs of cheap heavy-duty solid bearings:

 

Single replacement requires days of downtime – environmental penalty and compliance risk losses are hundreds of times the bearing price

 

Seal failures 4 times per year, 3 days each – 12 days unplanned maintenance annually, costing over €15,780

 

Fiber entanglement causes frequent seizure – replacement every 3 months

 

Lifting equipment cannot access underground pump rooms – hoisting costs and time increase significantly

 

Aerator bearings fail prematurely after submersion during heavy rain

 

NMT split bearings for water treatment deliver “no piping removal, no pump removal, quick bearing replacement without plant stoppage“ in lift pumps, aerators, clarifiers and sludge dewatering:

 

Downtime reduced by over 80% – From days to hours – environmental compliance risks dramatically reduced

 

No inlet/outlet piping removal – Pump body and water lines stay in place – avoiding secondary leakage risks

 

No large lifting equipment required – Bearings are handled in sections – no expensive crane rental

 

Corrosion-resistant materials resist sewage and corrosive gases – Stainless steel or anti-corrosion coatings effectively resist hydrogen sulfide, chlorine and other corrosive environments

 

Fiber-entanglement-resistant design – Optimized sealing prevents fiber and hair accumulation that causes bearing seizure

 

Superior sealing for high-humidity environments – Multi-barrier seals effectively block sewage and moisture intrusion

 

Extended life of equipment (motors, gearboxes, couplings) – Fewer disassembly cycles – longer overall equipment overhaul intervals

 

For municipal wastewater treatment plants, industrial effluent treatment stations, water supply plants and other environmental protection facility maintenance departments, the total cost of ownership with NMT split bearings for water treatment is significantly lower than the repeated disassembly and replacement costs of traditional heavy-duty solid bearings – what you save is not bearing price difference, but the enormous environmental compliance risk and operational uncertainty of “replacing one bearing, shutting down an entire treatment line.“