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Filtration · Duplex housings

Duplex housings

Two vessels, one changeover valve. Turn the handle, flow redirects, change the offline bag — with the process still running.

Duplex filter housing pair on a common manifold
The problem it solves

When the process cannot stop for a bag change

A duplex housing is two independent filter vessels behind a single changeover valve. One filters, one stands by. When the differential pressure climbs, you turn the valve, flow redirects instantly, and you change the bag on the vessel that is now offline — with the process still running.

ModelBag sizeFilter areaMax flowVolume
HLDP2P1SSize #10.25 m² each20 m³/h each15.5 L each
HLDP2P2SSize #20.5 m² each40 m³/h each27 L each

Two vessels per unit. Design pressure 10 bar, design temperature to 150 °C. Seals in silicone, Viton, EPDM or PTFE. Connections flanged, NPT or BSP.

Where it is specified

Continuous process duties

Petrochemical & refining

Continuous streams where a shutdown to change a filter is not a decision anyone is authorised to make.

Coatings, inks & resins

Where stopping means the batch skins or sets in the line.

Food & beverage

Continuous production runs where a stop means a clean-down.

Fine chemicals & cosmetics

High-value product where lost batch time is the real cost.

Power generation

Cooling and lubrication circuits that run continuously.

Water treatment

Pre-filtration ahead of RO, where downstream membranes must never see unfiltered feed.

Worth doing the sum. A duplex unit costs more than two single housings and a lot more than one. It is worth it exactly when the cost of stopping exceeds the difference — which on a continuous line is usually after the first or second changeover.
Price on application

Housings are quoted to duty — vessel size, material, seal compound, internal finish, connections and any certification requirement all move the price. Give us the fluid and the flow and you get a firm number, plus the expected bag change interval so you can budget the consumable too. Request a quote →

Tell us the duty, not the part number

Flow rate, fluid, temperature, particle size and how often you want to change bags. We size the housing and the bag around that and quote the pair, delivered and commissioned.

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