10/8E XM(R) Slurry Pump Premature Bearing Failure: Grease Selection, Filling Quantity, and Replacement Schedule

Subtitle: Lithium grease 2#/3# selection basis, standard filling quantity (grams), and relubrication interval – correcting the “more is better” myth to extend bearing life

Introduction

The 10/8E XM(R) is a medium‑sized AH series slurry pump (250mm inlet, 200mm discharge), widely used in heavy media coal preparation, mining slurry transport, and power plant ash handling. Its bearing assembly withstands high radial and axial loads, and lubrication quality directly determines bearing life, pump reliability, and maintenance costs.

Two common field mistakes exist: either never adding grease (bearings run dry and burn out) or believing “more is better” – over‑greasing causes overheating, grease carbonization, and seal damage. As a professional slurry pump manufacturer, this article covers grease selection, filling quantity calculation, over‑greasing hazards, and field operation procedures for 10/8E XM(R) pump bearings.

1. Why Lithium Grease 2#/3# Is Recommended for 10/8E XM(R)

The 10/8E XM(R) slurry pump bearing assembly uses grease lubrication. AH series horizontal slurry pumps recommend lithium grease 2# or 3#. Key advantages:

2# vs. 3#: 2# is softer (penetration 265-295), suitable for normal duty and centralized systems. 3# is harder (penetration 220-250), recommended for high‑temperature, heavy‑load, high‑vibration conditions. For continuous operation in harsh mining/coal preparation environments, 3# lithium grease is preferred.

2. Bearing Grease Filling Quantity Standard: More Is Not Better

For 10/8E XM(R) grease‑lubricated bearing assemblies, refer to the manufacturer’s standard table.

2.1 Standard Filling Quantity by Bracket Type

10/8E XM(R) typically uses E or F type brackets. Based on AH series standards:

Always refer to the pump nameplate or manufacturer manual.

2.2 Calculation Formula (When Manufacturer Data Unavailable)

Initial filling: Q = 0.01 × d × B

Where d = bearing bore (mm), B = bearing width (mm); result in grams.

Relubrication quantity: Q = 0.005 × d × B (approx. 50% of initial fill).

2.3 Bearing Cavity Volume Method

For open bearings, fill 1/3 to 1/2 of cavity volume – 1/3 for high speed, 1/2 for low speed. 10/8E XM(R) operates at 800-1200 rpm (medium speed), recommend 40%-50% of cavity volume.

3. Five Hazards of Over‑Greasing

Many maintenance personnel believe “more is safer” – this is a dangerous misconception. Over‑greasing causes more hidden damage than under‑greasing.

⚠️ Warning: If bearing temperature spikes sharply (>10°C) after greasing, check for over‑greasing first – do not blindly add more grease.

4. Hazards of Under‑Greasing

Under‑greasing is equally dangerous.

Normal condition: Bearing operating temperature stable at 60-70°C, no abnormal noise, no grease leakage at seals.

5. Field Greasing Procedure

5.1 Relubrication Frequency

5.2 Procedure

5.3 Prohibited Actions

• Never mix different brands or NLGI grades (chemical reaction may cause hardening)

• Never grease while pump is running – grease during shutdown or slow barring

• Never use degraded or contaminated grease

6. Bearing Temperature Troubleshooting Quick Guide

7. Case Study: Solving Bearing Overheating on a 10/8E XM(R)

Background: A 10/8E XM(R) pump drive‑end bearing ran at 88°C with increased vibration. The plant added ~300g of grease every 2 weeks.

Diagnosis:

• Bearing cover removed revealed dry, hardened old grease; new grease could not enter

• Measured grease quantity far exceeded standard (standard 200g)

Actions:

• Thoroughly cleaned bearing cavity, replaced with fresh 3# lithium grease (200g)

• Adjusted relubrication interval to 800 hours, 150g per addition

Results: Bearing temperature dropped to 65°C, vibration normalized, bearing life extended to over 2 years.

Conclusion

For 10/8E XM(R) slurry pump bearing grease selection and filling, the key principle is “right grease, right quantity.” More is not better – over‑greasing causes overheating, carbonization, and seal damage, actually shortening bearing life. Following the selection standard (lithium grease 2#/3#) and filling quantity guidelines (by bracket type or bearing bore calculation), and strictly adhering to field procedures, will significantly extend bearing life and reduce maintenance costs.

As a professional slurry pump manufacturer, we recommend maintaining a bearing lubrication log, recording each grease addition, and promptly investigating any temperature abnormalities. For on‑site lubrication diagnostics or grease selection advice, please contact our technical team.