How Filtration, Pumping, Control and Monitoring Work Together

A filtration system, a pump and a controller are bought as three products and installed as one system, and the system is where the problems appear. The filter is sized for a flow the pump must deliver, the pump is sized for a head that includes the filter, and the controller decides when either of them runs. Change one and the other two are suddenly mis-specified, which is why a system decision cannot be assembled from three separate quotations.

01 – Why each channel needs it, and where it is used

Channel	Role in this decision	Why they need it
Distribution and wholesale	Bundle categories that are used together	Selling a filter without knowing the pump is how a distributor ends up mediating a pressure complaint between two suppliers who each delivered a correct product
Contractors and integrators	Own the interface between components	The interface is where the warranty argument happens. A contractor who writes the duty statement controls that argument
Direct B2B users – farms, estates, nurseries, municipal green	Operate one system, not three products	Downtime is caused by the interface – dry running, blocked filter, pump cycling – rather than by one component failing alone
Specifiers and influencers – irrigation designers, water engineers, consultants	Define the interfaces in the design	Each interface is a number in the specification: filter loss, pump duty, control set point. If they are not written, they are discovered

The system appears wherever water has to be lifted, cleaned, measured and delivered: well-fed irrigation projects, reservoir-fed municipal green, nursery and greenhouse installations, farms with a dedicated pump set and landscape projects with a storage tank. In every one of those the same four interfaces exist – pump to filter, filter to network, meter to operator, controller to valves.

The sales consequence is simple. A buyer who assembles the system from three suppliers has three quotations that describe three components and no single document describing the installation. The supplier who offers the system can be asked for that document.

02 – How to make a preliminary selection

Start at the emitter and work backwards. The emitter class fixes the filtration class – 120 mesh is the published requirement for the pressure-compensating driplines cited throughout this series – and the number of emitters per zone fixes the zone flow. Add simultaneous zones to get the peak flow, and the peak flow fixes the filter capacity.

Then size the pump against the total head, which is the lift plus the delivery height plus the losses in pipework, valves and filter. The filter loss must be taken at the loaded condition, because the pump sees a dirty filter for most of its life. That single correction is where many systems lose the margin they were designed with.

Then place the measurement. A flow meter on the main and two pressure gauges – at the filter inlet and at the far end of the longest zone – turn the system into something observable. Without them, every fault is diagnosed from the plants.

Finally, set the control. The controller needs to know the zone count, the source’s limits and what to do when a fault appears. Where the pump can run dry, the control has to stop it; where the filter loads, the control has to signal it. Those two protections are what keep a system decision from becoming a maintenance crisis.

03 – Comparing the realistic options

The realistic comparison is not between brands but between two ways of buying: a system from one supplier, or components from three. The table frames what changes.

Question	Components bought separately	System specified together
Duty statement	One per supplier	One for the installation
Filter loss	Often omitted from pump sizing	Included at loaded condition
Protection	Each component protects itself	Dry run, blockage and cycling covered
Measurement	Optional	Specified at commissioning
Warranty	Interface is contested	Interface documented

That is also the argument for a written duty statement rather than a parts list, and for a commissioning record. Both exist to make the interface explicit before anything is installed.

03b – The commissioning record

Commissioning is where a system decision is confirmed or exposed. Run each zone and record four values: flow at the meter, pressure at the filter inlet, pressure at the far end of the longest zone, and the filter loss with a clean element. Those four numbers take an hour to collect and they describe the interface between the pump, the filter and the network better than any datasheet.

Repeat the record once the element is loaded. The difference between clean and loaded loss is the margin the design actually has, and it is also the number to quote to the next client when a similar system is specified.

04 – What goes wrong, and what still needs confirming

Three interface failures cover most cases. The pump is sized on the clean filter loss, so pressure falls away as the element loads. The filter is sized on average flow, so it is overrun at peak. The control has no dry-run protection, so a slow-recovering well damages the pump. Each looks like a component fault and each is an interface omission.

Items that still need written confirmation: the filter loss at both clean and loaded conditions; the pump duty including that loss; the meter’s range and installation requirements; the controller’s inputs and fault behaviour; the protection settings – level, pressure or flow; and the commercial terms for the package – MOQ, price, lead time and the documentation supplied. A quotation that does not state the assumed loss is not comparable with one that does.

05 – What we can supply and what to send

Delta AgriFlow supplies across the interfaces: deep-well pumps, pump control panels, filtration stations and compact filters, electromagnetic flow meters, PE pipe and valves, with dripline and sprinklers for the emission side.

Send six items for a system review: source and its variability; design flow and total head; protected equipment and filtration fineness; zone count and control requirement; power and control position; and the measurement points the operator can reach. With those, the three quotations become one specification.

For systems that already exist, the same logic works in reverse. Measure the four numbers at commissioning conditions, compare them with what the components claim, and the gap tells you which interface was mis-specified. That is usually cheaper than replacing parts in the order they fail, and it produces a record that the next project can use as its starting assumption rather than its lesson.

A final note on phasing: where a system is built in stages, the interfaces are the part that must be decided first. The pump can be added later, the filter can be added later, but the duty statement that connects them cannot be reconstructed afterwards without measurement. Writing it before the first stage is installed is what makes the second stage an extension rather than a redesign, and it is the cheapest deliverable in the whole project.

The same discipline works for a system that exists already: measure the four numbers at commissioning conditions, compare them with what each component claims, and the gap identifies the interface that was mis-specified. That is cheaper than replacing parts in the order they fail, and it produces a record that the next project can start from rather than repeat.

The measure of a good system is not that nothing fails, but that the failure is visible before the plants show it.

06 – Questions, sources and next steps

Can the filter be chosen after the pump? It can be checked afterwards, but it is usually re-chosen. The filter loss belongs in the pump duty, so the two decisions are one decision.

Is a flow meter necessary? On an unattended or commercial installation, it is the cheapest way to make the system observable. Pressure gauges at two points cover smaller sites.

What breaks first when the interfaces are missed? The pump, then the emitters. Dry running and sand wear appear first, because they are downstream of the omission.

Information boundary

This article describes how the decision is structured. It is not a performance specification and does not state capacity, flow, pressure or service-life values for a specific product. Those values are confirmed per project after a written quotation; manufacturer figures cited are the published values for those products, not project commitments.

Reviewed: 2026-10-26. Next review after supplier specifications are confirmed in writing.

Sources and further reading

• Rain Bird XFA 13 mm dripline datasheet – 120 mesh filtration requirement, 50-350 kPa compensating range
• Netafim Techflow bid performance specification – 120 mesh or finer filtration, 14.5-58 psi inlet range
• ISO 9912-1:2004 – Filters for micro-irrigation: classification
• FAO – Irrigation manual, Chapter 6: drip irrigation
• ISO 9906:2012 – Rotodynamic pumps, hydraulic performance acceptance tests

Assembling a system? Send source, design flow and total head through our quotation request.