Dairy CIP Station Tank Level Measurement and Process Control

A dairy CIP station commonly stores water, recovered rinse, caustic and acid solutions at different concentrations and temperatures. The same level technology may not suit every tank without material and process review. Measurement must support safe pump operation, prevent overflow and cross-contamination, and remain valid through heating, return flow and media changeover.

Define every CIP medium

List water quality, caustic and acid chemistry, concentration, temperature, contaminants and recovered-solution composition. Include dosing, heating, return, standby and cleaning states. Compatibility must cover vapour and condensate as well as bulk liquid.

Record density and temperature if level is compared with hydrostatic pressure or converted to mass. Concentration changes can shift density without a corresponding change in true liquid level.

Separate tank functions

Define refill control, pump low-level protection, heater permissive, high alarm, recovered-solution management and inventory separately. Set response time from actual pump and valve behaviour, not from a generic level percentage.

Identify how the automation confirms the correct tank and route. Level alone cannot prove that a valve matrix is sending the intended chemical to the intended circuit.

Verify materials and hygienic design

Check antenna, process seal, gasket, flange and exposed metals against hot caustic, acid and sanitizers. A material acceptable at ambient concentration may not be suitable at cleaning temperature. Obtain evidence for the full cycle.

Use drainable, cleanable connections and avoid stagnant nozzle pockets. Confirm surface finish and documentation where the site hygienic standard requires them.

Manage vapour and condensation

Hot solutions create vapour and strong temperature transitions. Radar avoids acoustic-velocity dependence but a condensate film or crystallized residue can affect the antenna. Follow mounting and projection requirements and provide safe inspection access.

Trend signal quality through heat-up and cool-down. An invalid or held value must be flagged to the PLC so it cannot continue enabling a heater or pump.

Prevent media mixing and pump damage

Test high and low alarms, pump permissives, valve sequence and recovery from communication or power loss. Include return-flow delay and liquid remaining in pipework when setting capacity margins.

Use conductivity, recipe state or other appropriate verification for chemical identity. A correct tank level does not prevent cross-contamination caused by a wrong valve route.

Commission the complete cycle

Verify known points for each tank and medium, then follow a representative CIP sequence through fill, heat, circulation, return and drain. Check local value, PLC scaling, HMI, historian and alarms.

Record chemical concentration, temperature and operating state with test results. Revalidate after chemical, seal, antenna, valve logic or piping changes.

Worked changeover review

A caustic recovery tank reads correctly when cold but becomes unstable during the hot return stage. Echo records show condensate forming in a recessed nozzle, while the independent volume balance remains consistent. The connection is corrected to the approved projection and retested through heat-up and circulation.

The acceptance record links the new echo curve to chemical concentration, temperature and valve sequence. Pump permissives use a clearly invalid quality state during any future signal loss, and conductivity remains the independent check for recovered-media identity.

Engineering checklist

List all CIP chemicals and temperatures.
Define pump, heater and overflow duties.
Verify complete wetted-material compatibility.
Use hygienic and drainable connections.
Test valve sequence and media identity controls.
Commission a representative CIP cycle.

Frequently asked questions

Can one radar model be copied to all CIP tanks?

Only after confirming material, temperature, geometry and duty for each medium.

Does level confirm the correct cleaning chemical?

No. Chemical identity and valve routing require separate evidence.

Why test during heating?

Vapour, condensation and density change may expose problems absent during a cold-water test.

Need a project-specific review? Send process data, drawings, cleaning conditions and acceptance criteria through our contact page.