Building Your Equipment Maintenance Strategy (asset maintenance plans)with Common Sense!
by Tina Idhammar
Figure 1: Boiler forced draft fan
Here’s a scenario – you are responsible for figuring out what maintenance to do on a Boiler Forced Draft fan. How are you going to approach this?
Let’s start with the basics:
- Essential care (EC) = prevention that extends the life
- Condition-based maintenance (CBM) = finding failure early
- Operate to breakdown (OTB) = corrective maintenance after the component shuts down the equipment
Step 0: Follow all safety requirements and procedures related to the work performed for your facility or plant.
Step 1: Divide the equipment in key components (because it’s components that break down):
- Electric motor components: bearings and windings
- Belt drive components: Timing belt, sheaves, and guard
- ID Fan: Bearings, shaft, and fan wheel
Step 2: Based on safety, process losses, or equipment cost decide on effective maintenance methods for each component.
- Grease motor and fan bearings, specifying lube type, volume and tools.
- Align motor to standard when installing motor.
- Balance motor and fan to standard when installing.
- Align and tension belt to standard when installing.
- Apply storage standard for spare belts and bearings.
- Visually inspect the motor cleanliness and take temperature readings.
- Visually inspect the belt drive using a strobe light.
- Take on-going vibration readings on motor and fan.
- Or based on cost.
- Install sensors for remote on-line measurements in control system or IoT of data and learning.Evaluate the cost based on buying/installing sensor, nodes, data processing center monthly fees etc. vs taking readings.
- This fan is necessary to operate the plant so the cost to maintain it is justified.
Step 3: Document inspections and baseline readings in your CMMS.
- Add start date and interval to schedule your PMs.
- If IoT or machine learning can be justified, based on cost, set up procedures for how to notify plant personnel of an equipment failure and how to do corrective maintenance, normally through your work management planning and scheduling system.
- Procedure should also include what and how to trigger troubleshooting and root cause problem elimination.
We coached our client through this process. Here are the results of the common senses process in action. The first inspection route, the team uncovered:
Figure 2:Strobe inspection of fan on-the-run
- Fan had high vibration – imbalance and early spalling in bearing.
- The Belt was misaligned, possibly didn’t have enough tension, and the belt was tracking off the sheave indicating misalignment.
- The motor base was vibrating induced by the fan, but the motor foundation bolts were loose and corroded, not absorbing any vibration into the base.
- The inspector generated a work request to repair all the equipment issues to precision standard.
Note: the fan had a history of belt and bearings being replaced.
Figure 3:On-the-run strobe inspection revealed belt was riding and tracking to the side
We observed the motor had been equipped with asensor. The next step was to include the sensors in the basic routes and use the phone app to capture data for vibration and temperature.The payback time for remote monitoring through Bluetooth and Wi-Fi nodes will be calculated over the life of the equipment. In this case, the sensor will only give an overall vibration reading, which is not capable of detecting an early bearing failure.
Get to work! What are your next steps after setting up the first asset plan?
- Review and update all other asset strategies and plans
- Develop work management, planning and scheduling workflows
- Process for root cause problem elimination
- Material management workflow and bill of materials
- Provide training in precision maintenance, essential care, condition monitoring, planning and scheduling, material management, and root cause problem elimination
If you are struggling with improving your Preventive Maintenance strategy, give us a call and we’ll help you build the strategy that works for your team.