Use this method when the access point supports the evidence required.
- Oil sumps with a defined drain population
- Investigation of settled contamination when intentionally targeted
- Assets without engineered live-line points
Recognise what can bias the result.
- Generally less repeatable than a live-zone sample
- First flow can contain settled debris
- Complete draining changes the operating condition
Materials and preparation.
Use laboratory-specified containers and clean dedicated accessories. Keep the cap, bottle mouth and tubing ends protected throughout the collection.
- 01Protected sample bottle
- 02Separate flushing or waste container
- 03Drain tool and clean external wipes
- 04Label, PPE and spill control
Field procedure and evidence protected.
Perform the sequence consistently. If a step cannot be followed, record the deviation because it may explain an apparent trend change.
- 01
Stabilise the operating condition
Collect during normal representative operation or, where the approved procedure requires shutdown, within 10 minutes. Record cold or non-standard sampling conditions.
- 02
Verify the asset and decision point
Confirm machine, compartment, lubricant, sample-point identity and the maintenance question before opening the kit.
- 03
Prepare clean equipment and records
Use the laboratory-specified bottle, labels, clean adapters or new tubing, a separate flushing container and the required PPE. Keep caps and bottle mouths protected.
- 04
Inspect and clean the sampling point
Remove the dust cover, check for blockage or damage and clean the external point without pushing dirt into the system.
- 05
Define what the drain sample represents
Decide whether the objective is bulk oil, settled bottom material or an oil-change sample and document that population.
- 06
Clean and open the drain safely
Clean around the plug or valve, position spill control and begin draining into the waste container.
- 07
Discard the initial flow
Allow sufficient oil to remove drain-port dead volume and visibly settled contamination unless that material is the stated target.
- 08
Collect the mid-stream sample
Move the protected bottle into stable flow without touching the drain hardware, then remove it before flow becomes weak or the sump is nearly empty.
- 09
Fill without contaminating the bottle
Keep the bottle upright and avoid contact with the bottle mouth. Leave suitable headspace; the source guide uses approximately one-half full above 150 cSt, two-thirds for 68-150 cSt and three-fourths below 68 cSt at 40 C unless the laboratory specifies otherwise.
- 10
Cap, clean and restore
Seal the bottle immediately, wipe the exterior, replace the port cover and return valves, bypasses and filtration equipment to the approved operating state.
- 11
Document and dispatch
Record asset and oil hours, top-up, filter or maintenance events, operating abnormalities, point, date and sampler. Package securely and send to the laboratory promptly.
Interferences, effects and controls.
A result may be analytically correct and still misrepresent the machine. Review these controls before escalating maintenance.
| Interference source | Possible effect on result | Field control |
|---|---|---|
| Inadequate flushing | Old fluid, settled debris or contamination in the adapter and dead volume can dominate the bottle. | Calculate dead volume and flush the required multiple into a separate container before filling the sample bottle. |
| Changing sample location | A clean downstream point, reservoir surface and active return line represent different particle populations. | Use the same labelled point and operating state for each trend sample. |
| Dirty bottle, cap, tubing or adapter | Added particles, water or residue can create false contamination alarms. | Use laboratory-specified containers, protect openings and use new or verified-clean wetted parts. |
| Settling or particle fly-by | Low-velocity zones can under-report settled material while poorly located high-velocity ports can miss the target population. | Select a turbulent, representative zone and document whether the objective is machine, filter or reservoir condition. |
Complete the task without creating a new hazard.
- Follow plant, OEM and permit-to-work requirements; the website does not authorise a sampling point or override site procedures.
- Confirm lubricant temperature and pressure before sampling. Use engineered pressure reduction and thermal protection where required.
- Wear eye and hand protection compatible with the lubricant and process hazards.
- Declare hazardous, toxic, flammable, biologically active or process-contaminated samples to the laboratory before shipment.
- Clean skin exposure promptly and follow site medical procedures for eye contact, ingestion or injection injury.
Retain the original field reference.
Complete manual, pages 16-18
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