A clarifier / thickener preventive maintenance schedule lists the checks and jobs done on the equipment at fixed intervals, how long each takes, and in what order of frequency, so problems are found before the clarifier / thickener fails. This page gives the schedule used in the PlantOps360 task library for clarifier / thickener (and dissolved air flotation (daf), which follows common industry practice for general-purpose equipment. It is also searched for as clarifier, thickener, DAF unit, dissolved air flotation.
The maker’s manual and your site safety procedures always come first where they differ. Intervals set by law differ by state.
Clarifier / thickener preventive maintenance schedule and checklist
| How often | Task | Estimated time |
|---|---|---|
| Daily | Check scraper or skimmer operation, sludge blanket and outlet clarity | 5 min |
| Weekly | Check air saturation pressure and recycle flow (DAF); clean nozzles | 15 min |
| Monthly | Check drive gearbox oil, torque limit switch and rakes; grease bearings | 30 min |
| Quarterly | Desludge and clean weirs, launders and lamella plates | 45 min |
| Half-yearly | Check chemical dosing (coagulant, flocculant, polymer) and mixers | 90 min |
| Annual | Drain and inspect tank, scraper and bearings; repair coating; calibrate instruments | 360 min |
Clarifier / thickener maintenance frequency and yearly workload
At the estimated times, one clarifier / thickener needs about 61 hours of preventive maintenance a year. The biggest single job is “Drain and inspect tank, scraper and bearings; repair coating; calibrate instruments” at 360 minutes, done annual. Multiply by the number of units you have to see the workload for your plant.
| Frequency | Tasks | Time per round | Hours per year |
|---|---|---|---|
| Daily | 1 | 5 min | 30.4 h |
| Weekly | 1 | 15 min | 13.0 h |
| Monthly | 1 | 30 min | 6.0 h |
| Quarterly | 1 | 45 min | 3.0 h |
| Half-yearly | 1 | 90 min | 3.0 h |
| Annual | 1 | 360 min | 6.0 h |
What goes wrong on a clarifier / thickener without preventive maintenance
- Scraper drive and gearbox damage
- Overloaded or stuck mechanisms
- Saturation system and recycle pump faults
- Sludge blanket carry-over
What to watch between services
- Drive torque and gearbox oil
- Air saturation pressure and recycle flow
- Effluent clarity
Safety and statutory notes for clarifier / thickener maintenance
Do not walk on covers or into tanks without fall protection and gas testing.
Where a clarifier / thickener preventive maintenance schedule is used
This equipment is used in the industries below. Each link opens the preventive maintenance schedule guide for that industry, and the maintenance software page where we have one.
- Preventive maintenance schedule for chemical, fertiliser and petrochemical plants · maintenance software for chemical
- Preventive maintenance schedule for food, dairy and beverage plants · maintenance software for food processing · maintenance software for dairy
- Preventive maintenance schedule for agro, grain, edible oil and sugar plants · maintenance software for sugar and distilleries
- Preventive maintenance schedule for packaging, paper and printing plants · maintenance software for packaging · maintenance software for paper and pulp
- Preventive maintenance schedule for textile and garment mills · maintenance software for textile
- Preventive maintenance schedule for steel, foundry, forging and metal plants · maintenance software for steel and metals
- Preventive maintenance schedule for oil, gas and refinery facilities · maintenance software for oil and gas
- Preventive maintenance schedule for water and wastewater utilities
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Browse the full list of equipment preventive maintenance schedules (317 types).
Run this clarifier / thickener schedule in maintenance software
In preventive maintenance software, each row above becomes a recurring task on the asset with its checklist, time estimate and parts. Tasks can be triggered by calendar date, running hours, meter readings or production cycles, each completed task is recorded with the person and date, and a failed check can open a work order. For the method behind it, read the guide to the preventive maintenance schedule, or use the free generator to get a 12-month plan for your whole equipment list.
Build my preventive maintenance schedule (free Excel)
Frequently asked questions
How often should a clarifier / thickener be serviced?
In our schedule a clarifier / thickener has 6 tasks: 1 daily, 1 weekly, 1 monthly, 1 quarterly, 1 half-yearly, 1 annual. The biggest job is “Drain and inspect tank, scraper and bearings; repair coating; calibrate instruments”, which is done annual. Always follow the maker’s manual where it gives a different interval.
What is included in clarifier / thickener preventive maintenance?
It covers routine checks and jobs such as “Check scraper or skimmer operation, sludge blanket and outlet clarity”, “Check air saturation pressure and recycle flow (DAF); clean nozzles”, “Check drive gearbox oil, torque limit switch and rakes; grease bearings”, up to the annual overhaul or inspection. The full list with times is in the table above.
How many hours of maintenance does a clarifier / thickener need per year?
About 61 hours per unit per year at the estimated times in our library, including the daily checks done every day. Use it to plan workload, not as a benchmark.
Is there a free clarifier / thickener maintenance checklist?
Yes. The table on this page is a ready checklist. The free preventive maintenance schedule generator turns it into a 12-month Excel schedule for your list of equipment, with monthly workload hours.