Cleaning that is documented is cleaning that holds up under audit. The Alfa Laval Rotacheck Basic and Plus is the tank cleaning validation sensor that gives your team objective evidence — cycle by cycle — that the Alfa Laval Rotary Jet Head is rotating and impacting as designed, and that any deviation is caught before it becomes a quality incident.

How the rotary jet head monitoring sensor works

The Rotacheck consists of a sensor unit with top cover, O-rings, and electrical cable or connector. The sensing element sits inside the tank and registers each impact of the water jet from the rotary jet head. A sensor board processes the signal and communicates it to the PLC via a PNP interface. Status is also shown through a visual light indication on the unit, so operators on the tank deck get immediate feedback alongside the digital signal sent to the control system.

Rotacheck Basic vs Rotacheck Plus: which CIP validation approach fits your control system

The Basic version sends a digital signal to the PLC every time the water jet hits the sensor. Validation logic lives in the PLC, which interprets the Hit, Alarm, and Idle states. It suits plants that already host cleaning validation logic centrally and want a robust digital input rather than a parallel layer of intelligence on the tank.

The Plus version performs validation inside the sensor itself. During the first CIP cycle, it records time and pressure data and stores a reference pattern of water-jet intensity and the time between hits. On subsequent cycles, the onboard processor compares actual values to the stored reference and flags any deviation. The PLC receives a clean Rotation OK, Alarm, or Idle output without having to reconstruct the cleaning pattern itself — useful when PLC capacity is constrained or when validation must be portable between tanks.

Hygienic design and materials for 3-A and EHEDG compliance

Wetted parts are AISI 316L, the fieldhousing is Polymer PA12, and the product-wetted elastomer is EPDM with NBR used elsewhere. Product-wetted surface roughness is Ra 0.5 µm to support thorough cleanability and minimise residue. The process connection is the Alfa Laval Hygienic Tank Connection (HTC), which simplifies installation in tank tops and aligns with existing hygienic interfaces. The unit is approved to carry the 3-A symbol and is designed according to EHEDG hygienic guidelines, and it is compatible with PW and WFI systems for pharmaceutical and high-purity duties.

ATEX-approved cleaning sensor for Zone 0/20 and Zone 2/22

Rotacheck is approved under ATEX Directive 94/9/EC for use in Zone 0/20 in the product-wetted area and Zone 2/22 in the non-product-wetted area. Ex identification is II 1/3G Ex ia/nA IIB T4/T3 Ga/Gc and II 1/3D Ex ia/tc IIIB T130 °C Da/Dc. The unit must not be separated when energized. T4 applies to media temperatures below 85°C and T3 below 140°C, giving design teams clear thermal limits for hazardous-area planning.

Pressure, electrical, and integration details

Maximum working pressure in the tank while performing monitoring is 0.3 bar / 4.35 PSI, and the diaphragm withstands a pressure overload of 15 bar / 217 PSI. The power supply is 24 Vdc ±10% with maximum 70 mA consumption. Outputs are Logic PNP with a maximum of 50 mA per output, and the electrical connection is either an M12 8-pole plug or an M16 cable gland. Short-circuit and brownout protection follow EN 61131-2, and surge immunity follows EN 61000-4-5. Ingress protection is IP66 and IP67, and the unit weighs approximately 600 g.