Why Preventive Maintenance?

Reactive maintenance (fixing breakdowns) costs 3–5× more than planned preventive maintenance. In dairy plants, breakdowns cause:

  • Product losses (milk held at wrong temperature)
  • Food safety risks (contamination from failed seals)
  • Production losses worth ₹1,000–10,000 per minute downtime
  • Regulatory non-compliance

PM Frequency Framework

Daily Checks (Operator Level)

Performed by production operators at start/end of shift:

  • Vibration and noise check (walk-around inspection)
  • Temperature and pressure readings at pasteurizer
  • Separator RPM and bearing temperature
  • Pump seal condition (no leakage)
  • Conveyor belt alignment and tension
  • Refrigeration system evaporator frosting pattern
  • Boiler water level, steam pressure, blowdown

Weekly Maintenance

Performed by maintenance technician:

  • Lubricate all grease nipples (refer to lubrication chart)
  • Check coupling alignment on centrifugal pumps
  • Test FDV (flow diversion valve) operation on pasteurizer
  • Inspect air compressor filters
  • Test high-temperature cutoff on pasteurizer
  • Check separator bowls for desludging requirement
  • Inspect conveyor chains for elongation

Monthly Maintenance

  • PHE inspection and gasket check
  • Pump impeller inspection (centrifugal pumps)
  • Motor bearing temperature survey (IR thermometer)
  • Check all pressure gauges and temperature sensors vs. calibrated reference
  • Inspect boiler safety valves, water level gauges
  • Review and calibrate milk analyzers (Gerber or FOSS)

Quarterly Maintenance

  • PHE regasketing (if fouling rate requires)
  • Separator bowl disassembly and cleaning
  • Homogenizer valve seat inspection and replacement
  • Complete pump overhaul (rotary lobe pumps)
  • Boiler internal inspection (with licensed IBR inspector)
  • CIP pump mechanical seal replacement
  • Motor winding insulation resistance test (Megger)

Annual / Shutdown Maintenance

  • Major overhaul of all centrifugal separators
  • Full PHE inspection and pressure test
  • Boiler insurance inspection (mandatory under IBR)
  • Calibration of all instruments by certified lab
  • Fire safety system inspection
  • Electrical panel thermography survey

Critical Lubrication Guide

EquipmentLubricant TypeFrequency
Centrifugal pump bearingsGrease (food-grade)Monthly
Separator spindleSpecialized separator oilPer manufacturer schedule
Conveyor chainFood-grade chain oilWeekly
GearboxGear oil (ISO VG 220)Oil analysis / 6 months
CompressorCompressor oil500 hours
Agitator gearboxFood-grade EP gear oil3 months

Condition Monitoring Tools

  • Vibration meter — catch bearing failures 4–6 weeks early
  • IR thermometer / thermal camera — detect hot bearings, electrical faults
  • Ultrasonic tester — detect steam leaks, bearing failure, valve leakage
  • Oil analysis — reveal gear and bearing wear 3–6 months early

TPM (Total Productive Maintenance) in Dairy

TPM involves operators taking ownership of basic maintenance:

  1. Autonomous Maintenance — operators clean, inspect, lubricate daily
  2. Focused Improvement — systematic elimination of chronic losses
  3. Planned Maintenance — scheduled PM system
  4. Quality Maintenance — eliminate quality defects from machine condition
  5. Training & Education — build skills across all levels

Starting TPM: Begin with a 5S program (Sort, Set, Shine, Standardize, Sustain) before implementing autonomous maintenance.

Download our free Maintenance Checklist for dairy plant equipment.