Donaldson DF Ultra-Filter Compressed Air Filter Housing

A compact compressed air filter housing in ten sizes

The Donaldson DF Ultra-Filter is a filter housing for compressed air and other gases, sold in ten sizes from DF 0035 to DF 1450. Donaldson states that the range covers flow rates from 35 to 1450 m3/h, which corresponds to conventional compressor capacities between 2 and 120 kW. Performance data is validated according to ISO 12500-1, ISO 12500-2 and ISO 12500-3 so that the compressed air quality required by ISO 8573-1 can be reached reliably. The housing is die-cast aluminium, immersion-lacquered inside and outside for corrosion protection, and uses a bayonet fixing: the filter bowl is rotated slightly and removed together with the element, which needs only a few centimetres of clearance below the unit. The bowl cannot be opened while the housing is under pressure.

Donaldson lists three versions. The Standard version has a float condensate drain and a mechanical Econometer differential pressure indicator. The Plus version has a float drain and the Economizer, an indicator that works out the most economical time to replace the element and can transmit data remotely. The Superplus version combines the Economizer with the electronic level-controlled UFM-D condensate drain, which works without compressed air losses.

Technical specifications

Sizes, connections and filter elements

Element grades are selected by the filtration task. The B element is a particle filter rated 100 % efficiency related to 25 µm. The A element is an activated carbon filter with 0.003 mg/m3 total residual oil when connected downstream of an M or S element. The V and M elements are coalescence and particle filters with residual oil aerosol content below 0.2 mg/m3, and the S element reaches below 0.01 mg/m3 at an inlet concentration of 3 mg/m3. Initial differential pressure at nominal flow and 7 bar in dry condition is 0.08 bar for M, 0.10 bar for S, 0.11 bar for V, 0.12 bar for B and 0.13 bar for A (DF 1450: 0.12, 0.16, 0.20, 0.21 and 0.25 bar).

Applications, ordering code and documents

Donaldson names central compressed air processing, final filtration of control and process air, protection of adsorption dryers, and paint and lacquer finishing air in the automotive industry as typical uses. Industries listed include chemical and pharmaceutical, PCB assembly, surface finishing, machine building and energy generation. Changing the coding clip inside the filter cover reverses the flow direction so the same housing can run as a coalescing or a particulate filter, and an adapter allows several filters to be combined.

The ordering code follows the pattern DF – element type – size – Economizer Z – drain U, for example DF – S 0035 Z U for an S element, size 0035, Economizer and UFM-D03 drain. Other options are K for the UFM-P or KA 1/2 float drain, M for the Econometer, S for a plug and P for a plate, plus a wall bracket (except on the DF 0035). Send the flow rate, operating pressure, air quality target and connection size and the correct code can be confirmed. The attached Donaldson datasheet carries the full dimension tables. Related equipment is in the filter housings category.