Test: 4.5” Ditch Witch Rock Tool
Start Date: 06/21/2016
Testing Method: Customer testing
Location of Test: Manassas Virginia area
Objective of Test: Extend service life of bearings
Typical Failure Mode: Contamination and heat
Background:
The Ditch Witch AT30 Horizontal Directional Drill uses a patented mechanical driven 2 pipe system for rock drilling. The Electronics housing is designed with a specific degree offset for steering. The bearing assembly is located in the front section of housing separating the inner and outer drive for steering purposes. The typical rebuild for the bearing and seal packs are 50-100 hours with service interval at 8 hrs. The tool must be flushed after each use or every 8 hours. Flushing the tool with grease purges the system of any contamination that may have passed the seals during operation.
Both tools were tested on same machine, operator, and conditions. Testing was ended when excessive contamination was evident during the flushing of the tool.
Testing Results of tool (with) RF85 treatment to bearings
Total Hours on Tool: 123
Total Bearing Revs: 959,400
Average inner rotation pressure: 1200 psi
Note: Bearings tested with RF85 were removed from assembly and sent to the bearing manufacture for inspection. Results on next slide.
Testing Result (without) RF85 treatment
Total Hours on Tool: 69
Total Bearing Revs: 538,200
Average inner rotation pressure: 1300 psi
Conclusion:
Based on the two tools tested the RF85 treatment extended the life of the bearings and reduced the inner rotation pressure. Although the reduction seems small at 8.3% this increase ads value by putting more downhole torque to the rotary bit. An increase of torque to the bit allows for more weight on the bit to be applied increasing the penetration rate and speed of production.