A strong solution for efficient needle washing

Diagnostic equipment frequently use needles for dosing reagents and transferring patient samples, in order to carry out critical diagnostic tests. These needles need to be thoroughly washed to avoid cross contamination and to eliminate the risk of false-positive test results. However, this process can be surprisingly demanding. To thoroughly wash needles, cleaning solution must be forced through at a sufficiently high flow rate to ensure the removal of all residues.

Needles and other fluidic components in diagnostic systems need to be washed thoroughly between each use to prevent cross contamination, maintain a clean fluidic system, and ensure every diagnostic test can be trusted. The needles need to be cleaned completely, both inside and out, typically with a solution made from deionized (DI) water mixed with cleaning agents. A pump is used in a washing station forces the cleaning solution through the needles at a high flow rate to ensure cleanliness. Other operations use cleaning baths which require pumps to fill and empty. Reducing the amount of liquid used is important, as it reduces the amount of waste removal required. A quick process time is also desirable to maximise sample throughput.

Unique challenges

Needle washing stations are often complex systems that require high volumes of media to be moved very quickly. These systems typically require several liquid pumps that must meet a variety of requirements. The cleaning solution cannot be flushed through the system with too much pressure, but it needs to be transferred forcefully enough to remove debris. The flow rate and pressure required can vary greatly from system to system, depending on the size and number of needles to be cleaned. The pumps must be able to withstand back pressure and remain leak tight. In some cases, they must also be able to transfer aggressive cleaning agents.

KNF's NF series pumps are an ideal choice for needle washing stations. They are self-priming and offer excellent reliability. Depending on the exact application, they offer the required flow rate with excellent maximum pressure and suction height. The NF 1.25 has a flow rate of 0.3 l/min with a maximum pressure of 6 bar (rel.) and a maximum suction height of 3 mH2O. For applications where higher pressure is required, the NF 1.60 version may be required. It offers a flow rate of 0.65 l/min with a maximum pressure of 6 bar (rel.).

These NF series pumps can be fitted with FDV pressure control valves to reduce potential leaks and protect against overpressure in the pump and system. They offer contamination free media transfer and a variety of motor options for additional controllability. KNF pumps can be customised to meet specific application requirements. They are also available with chemical resistant diaphragms for applications where required.

The FP 70 is also an outstanding option, especially in applications where additional parameterisation is required. It is available with a specialised, customisable BLDC motor for fast startup and superior flow control. The FP 70 has a flow rate of 0.7 l/min with a maximum pressure of 2 bar (rel.) and a maximum suction height of 3 mH2O. It is self-priming and provides contamination free media transfer.