From test pump to assembled manifold: micropumps as OEM components

At first glance, a micropump seems like a simple stand-alone component. In practice, for many instrument manufacturers it turns out to be the starting point of a much deeper journey: from trying out a single pump to purchasing a fully assembled manifold module that is mounted ready-to-use in the instrument. This article describes how that journey unfolds and what it delivers.

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Why micropumps are so well suited to OEM integration

At its core, the Bio-Chem Fluidics micropump is a solenoid-driven diaphragm pump: compact, electrically controllable, self-priming and available in fully inert versions. Each of these properties is valuable to an OEM designer, but it is precisely their combination that makes the micropump such a special building block for instruments.

Thanks to their compact size, several pumps fit side by side in the space traditionally reserved for a single peristaltic head. The pump also switches directly from a PLC or microcontroller, without an additional mechanical interface. The self-priming capability reaches up to 1.3 metres below the pump, so the liquid reservoir can be placed outside the instrument. Moreover, the entire fluid path, from inlet via diaphragm to outlet, contains no metal surfaces that react with aggressive reagents or biological samples, so even the most demanding media flow safely.

The isolation principle as a key advantage

The solenoid and the diaphragm are mechanically connected but completely separated in terms of fluid. The medium never touches the coil, the spring or the housing. This makes the pump suitable for applications in which cross-contamination, leakage to electrical components or chemical attack of the drive are unacceptable; a requirement in pharmaceutical and medical environments.

Two journeys from practice

Pharmaceutical production line: accurate filling of medicine vials

A manufacturer of pharmaceutical filling machines was looking for a solution for the simultaneous and accurate filling of multiple medicine vials on a production line. Each vial must receive exactly the same volume; deviations are unacceptable in pharmaceutical production and are directly linked to product approval and batch documentation.

The challenge was twofold. First, multiple pumps had to work synchronously and with identical dispensing accuracy, so that all vials are filled simultaneously and evenly in one cycle. Second, the pharmaceutical production environment requires daily cleaning: at the end of each production run, the entire fluid path is flushed with a cleaning agent. The pump and the fluid path must withstand this without degradation, cycle after cycle.

The choice fell on the 139SP in a manifold version. The 139SP is specifically designed to mount directly on a manifold block, without external tubing between pump and manifold. As a result, all fluid paths run internally through the block, eliminating connections that can leak or retain residue during cleaning. The manifold is made of a material that tolerates both the medicine and the daily cleaning agent. In addition, the pump heads can be quickly removed for inspection or replacement, which is in line with GMP requirements for pharmaceutical production equipment.

Inacom supplies the assembled module as a single unit, tested for dispensing accuracy and leakage, so that it is ready for direct installation in the filling machine. This allows the instrument manufacturer to validate the module as a whole instead of individual components, which considerably reduces the qualification burden during commissioning.

Water analysis: reagent dosing in a TOC analyser

A manufacturer of online TOC (Total Organic Carbon) analysers for industrial and drinking water monitoring was looking for a compact, reliable solution for accurately dosing chemical reagents in a continuously operating measuring system. A TOC analyser works with aggressive liquids: the oxidising agent that breaks down the organic compounds in the water sample, the acid that acidifies the system for measurement, and the sample itself. All three streams must be dosed independently and accurately at the moment the measuring cycle requires it.

The requirements for the pump are high in this application. First, the oxidising agent is corrosive and places high demands on the inertness of the fluid path. In addition, the instrument operates unattended in the field, sometimes for years without overhaul, so the lifetime of the pump is a direct factor in the availability of the analyser. Finally, dosing accuracy directly affects measurement quality: a deviating reagent quantity gives an incorrect TOC value.

The journey started with validating a single 139SP micropump on the actual reagents. After confirming chemical compatibility and dispensing accuracy, Inacom developed the design into a manifold assembly with three pump heads, one per medium, combined on one block with internal fluid paths. Because the 139SP is specifically designed for direct manifold mounting, the pump head connects directly to the manifold face without intermediate tubing or fittings. This keeps the internal fluid architecture tight and leak-free, and all connections between pump and measuring cell run internally through the manifold.

For field maintenance, the entire manifold module can be replaced as a single unit. The service engineer replaces the module in a few minutes without tools and without any knowledge of the internal fluid architecture. The replaced module goes back to Inacom for inspection and reconditioning, after which it can be used again.

The OEM journey step by step

Both journeys above followed the same pattern. That pattern is no coincidence; it is the most efficient route from an initial idea to a production-ready module.

1. Single pump validation

Test with one pump on the actual medium, the actual cycle frequency and the actual temperature. Validate dispensing volume, repeatability and material compatibility.

2. System design

Expand the concept to the complete fluid path. Define the number of streams, the switching sequence, the required valves and the spatial integration constraints.

3. Manifold design

Design the manifold block with internal fluid paths, pump positions, valve positions and connection points. Bio-Chem supplies manifolds in PTFE, PEEK, PPS, POM, PVC and acrylic.

4. Assembled module

Pumps, valves and manifold are assembled, tested and delivered as a single unit. The customer mounts the module in the instrument as one component.

Why starting early with the manifold pays off

Instrument designers who only introduce the manifold at a late stage of the design often run into space problems or awkward line routings. The manifold design is most flexible in the early design phase, when the layout of the instrument is still open. Inacom is happy to think along early in the process about the optimal position and configuration of the pump module.

Material selection: pumps and manifold

Both the pump heads and the manifold block itself must be chemically compatible with all media flowing through them. The Bio-Chem Fluidics micropump is available in a combination of body materials, diaphragm materials and check valve elastomers. The manifold block is custom-made in the material that best suits the application. Choosing all these materials together is the first and most important decision in any OEM journey.

PTFE

Maximally inert. Acids, bases, solvents. Most aggressive applications.

PEEK

High mechanical strength, broad chemical range. Chromatography, analytical chemistry.

PPS

Good chemical resistance, dimensionally stable. Water analysis, mild to moderately aggressive reagents.

POM

Dimensionally stable, good mechanical properties. Non-aggressive liquids and buffers.

Acrylic

Transparent, good visibility of fluid paths. Non-aggressive liquids, lab environments

PVC

Cost-effective, widely applicable. Water treatment, non-oxidising media, field applications.

FFKM

Most inert elastomer for check valves. Strongly oxidising media, acids, high temperatures.

PTFE diaphragm

Fully inert diaphragm. Combine with a PTFE body for maximum chemical inertness.

EPDM diaphragm

Flexible, suitable for aqueous media and mild chemicals. Standard choice for non-aggressive liquids.

Tip: always test on the actual medium

Material tables give an indication, but are never a guarantee. Concentration, temperature, pH and the presence of co-solvents affect compatibility. Inacom always recommends an accelerated compatibility test on the actual process medium before a manifold design is finalised. Bio-Chem Fluidics can supply test sets for this purpose.

What an assembled module delivers for the instrument manufacturer

Shorter assembly in production

Placing and connecting one module takes less time than mounting, connecting and testing several separate pumps. This directly reduces production time per instrument.

Guaranteed quality on delivery

The module is tested before delivery. Dispensing accuracy, leakage and electrical continuity have been checked. The instrument manufacturer does not need to retest on receipt.

Simpler field maintenance

A replaceable module in the field drastically reduces service costs. The operator replaces the entire module as a single unit instead of diagnosing individual components.

Fewer internal lines and connections

Internal fluid paths in the manifold block replace external tubing and fittings. Every connection that disappears is one less potential leak point and a reduction in complexity in the instrument layout.

Smaller footprint in the instrument

A manifold integrates multiple functions in one volume. This creates space in the instrument for other components or enables a smaller instrument housing.

One supplier, one point of contact

Inacom supplies the complete module and is the point of contact for technical questions, modifications and replacements. The instrument manufacturer does not need to coordinate between the pump, valve and manifold manufacturers.

When does a manifold solution make sense?

Not every OEM project justifies a manifold design. A single pump with standard connections is sufficient for simple applications. A manifold becomes worthwhile as soon as two or more of the following situations apply.

The instrument contains three or more fluid streams that must be pumped or switched independently of each other. Or space in the instrument is limited and separate tubing and fittings create an integration problem. Or the instrument is produced in large numbers and the assembly costs per unit are significant. Or the instrument operates unattended in the field and field maintenance must be as simple as possible. Or the fluid paths must be free of cross-contamination and separate tubing offers insufficient certainty.

If several of these points apply, the step to a manifold assembly is almost always worthwhile, both technically and economically.

Bio-Chem Fluidics has built manifolds for 84 pumps on a single block

The scale of manifold solutions is virtually unlimited. Over the years, Bio-Chem Fluidics has designed and produced manifolds ranging from simple two-pump blocks to complex assemblies with 84 pump heads on a single PTFE block for large-scale diagnostic platforms. The engineering is fully customised and always starts from the functional requirements of the instrument.

How the journey works at Inacom

Inacom is the Dutch distributor of Bio-Chem Fluidics and supports OEM customers not only in the supply of components, but also in the design and validation process. This starts with supplying test pumps for the initial validation phase and continues through to the delivery of assembled, tested manifold modules for series production.

The manifold design is created in collaboration with Bio-Chem Fluidics. Together, we align the engineering of the fluid path, the choice of materials, the internal bore geometry and the mounting positions of pumps and valves with the exact requirements of the instrument. We then test prototypes at the customer's site at an early stage, so that modifications can still be made easily.

For series production, Inacom supplies the modules fully assembled and tested. In addition, Inacom manages the inventory and delivers on call-off, in line with the customer's production rhythm.

Start early in the design process

The most successful OEM journeys start when the instrument is still in the concept phase. At that point, the fluid architecture can still be freely defined and the manifold geometry can be optimised for the available space. Joining later is always possible, but more often leads to compromises in the design.