Filling fault guide

How should liquid filling machine faults be diagnosed?

A structured way to separate product supply, measurement, delivery, nozzle and container causes without losing the original evidence.

Safety first

Preserve evidence before changing filling settings.

Make the equipment and product safe under the site's procedures, then record the original alarm, product condition, container position, nozzle involved and the last production event. Do not bypass guards, interlocks or authorised maintenance boundaries to continue running.

Filling faults are easiest to diagnose when the symptom is tied to a point in the sequence: product supply, measurement, delivery, nozzle shut-off, container transfer or verification. Changing several parameters at once can hide the initiating cause.

Capture before reset

Product batch and operating temperature
Fill recipe and machine format
Nozzle or station affected
Alarm and event history
Container and product samples
Last replenishment, clean or changeover
Video from a safe external position where permitted

Symptom guide

Separate supply, measuring, nozzle and container causes

The same visible symptom can have more than one initiating condition.

Symptom	Evidence to inspect	Diagnostic boundary
All fills drift together	Product level or pressure, temperature, supply pump, recipe, calibration and reference measurement	Likely shared condition rather than one nozzle, but verify before adjustment
One head differs	Valve, seal, hose, air, nozzle, local setting and blockage at the affected path	Compare with a known stable head under the same supply condition
Restart fills differ	Priming, product settling, pressure equalisation, air and first-cycle sequence	Separate start-up method from stable-running performance
Drips or strings	Nozzle shut-off, retained pressure, product rheology, valve wear and movement timing	Observe exactly when the drip begins
Foam or splash	Nozzle height, impact, velocity, air entrainment, container opening and product temperature	Determine whether foam is generated upstream or during delivery
Containers wet externally	Nozzle alignment, bottle position, overflow, splash and transfer after fill	Identify whether contamination starts before, during or after the fill

Diagnostic sequence

Change one verified cause at a time

Use authorised procedures and preserve the original condition until it is understood.

Confirm the measurement.Verify tare, scale, sampling and the agreed fill criterion before concluding that the machine is wrong.
Bound the symptom.Determine whether it affects every container, one head, one format, start-up or a particular time.
Check product supply.Observe level, pressure, air, temperature, settling and replenishment.
Inspect the product path.Within authorised access, check valves, hoses, seals, nozzles and signs of leakage or blockage.
Reproduce safely.Use a controlled sample sequence and one justified change at a time.
Verify the correction.Test the difficult condition, restart and representative production period before closing the fault.

Escalation evidence

Describe the pattern, not only the final reject.

Support can respond more effectively when the fault is bounded. State whether it is constant, intermittent, nozzle-specific, format-specific or linked to a production event. Include the last action that temporarily clears it and how long that correction remains effective.

If the application has changed, provide the new product, container or dose condition. A fault may be a compatibility boundary rather than a failed part. Compare the method with the filling machine types guide.

Where a fault involves safety functions, protected settings, product hazard or work beyond the site's authorised maintenance procedure, stop and obtain competent support.

Useful support package

Machine and format identification
Product and fill condition
Measured results by time and nozzle
Alarm sequence and photographs
Recent changeover, cleaning or maintenance
Actions already taken
Representative affected and acceptable packs

Buyer questions

Questions about liquid filling machine faults

Use the symptom pattern to select the next safe check.

Why do fill weights or volumes vary between containers?

Fill results may vary because product supply, air content, temperature, viscosity, measuring components, valve timing, nozzle shut-off, container presentation or the measurement method is changing. The error pattern should be recorded by nozzle, time and production event.

Check the reference measurement before adjusting the machine. A scale, tare or sampling problem can imitate a filling fault, while a true process fault may affect only restart or one product path.

How can filling nozzle dripping or stringing be diagnosed?

Diagnose dripping by observing when product leaves the nozzle: during deceleration, after shut-off, while the nozzle moves or after pressure changes in the supply. Product viscosity, trapped pressure, valve condition, suck-back, nozzle geometry and temperature can all contribute.

Do not compensate only by increasing delays if the product path is damaged or unsuitable. Keep guards and safety procedures in place and use authorised settings or competent maintenance.

Why does a liquid foam during filling?

Foam can be created by product impact, excessive velocity, air entering the supply, nozzle position, agitation, return flow or the product's formulation and temperature. The solution may involve product preparation, supply stability, nozzle movement or a different filling principle rather than simply slowing one setting.

Record foam at the start, during stable running and after replenishment. This shows whether the cause is persistent or linked to a production event.