Danfoss 023Z0193 DML 306 Filter Drier 3/4" Flare

Danfoss DML 306 (order code 023Z0193) is a hermetic filter drier installed in the liquid line of refrigeration and air conditioning circuits. It has 3/4" SAE flare connections and a filter volume of 30 in³. It belongs to Danfoss's ELIMINATOR® family.

Removes Moisture, Acid and Solid Dirt from the Liquid Line

A filter drier has three jobs: removing moisture, acid and solid particles from the circuit. Moisture remaining in the circuit combines with refrigerant and oil to produce acid; acid damages winding insulation and destroys the compressor. Moisture also freezes at the outlet of the expansion valve and blocks the line, and the system stops cooling.

The core is a solid block (solid core). The granules are bonded together and cannot move against each other — no shed dust contaminates the system. Because the body diameter is large, the liquid flow velocity stays low and pressure loss is minimized. The 25 μm filter at the outlet retains solid particles.

The difference between DML and DCL is in the core. The DML core is 100% molecular sieve — it has the highest moisture retention capacity and does not deplete oil additives. DCL contains 80% molecular sieve + 20% activated alumina; alumina retains acid but in additive-containing POE/PAG oils it also absorbs the additives. This is why Danfoss recommends DML in systems with additive-containing POE/PAG oils. For acid cleanup after a compressor burnout, however, DCL is preferred.

Technical Specifications (Official Danfoss DML/DCL Datasheet)

• Order code: 023Z0193 · type DML 306
• Connection: 3/4" (19 mm) SAE flare — inlet and outlet the same size, no brazing required
• Filter volume: 30 in³ · body volume 0.72 L (net 0.464 L)
• Core: solid core, 100% molecular sieve · surface 378 cm² · volume 256 cm³
• Filter: 25 μm — high retention, low pressure loss; thermally stable up to 120 °C
• Max. working pressure: PS 46 bar — PED approved
• Temperature range: −40 … +70 °C
• Dimensions: total length L 258 mm · body length A 186 mm · inlet side ØD1 80 mm · outlet side ØD2 76 mm
• Net weight: 1.45 kg
• Body: corrosion-resistant powder-coated steel (a special coating option is available for marine conditions)
• Compatible refrigerants: R134a · R404A · R32 · R410A · R407C · R407F · R23 · R1234yf · R1234ze · R448A/R449A · R452A · R444B · R450A · R290 · R600 · R600a
• Oil: mineral, AB, POE/PAG (including with additives) — DML is recommended for all

• 🔧 Mounting orientation is free — the only requirement is that the arrow on the body points in the flow direction. Danfoss makes no vertical/horizontal distinction.
• 🔧 Installation point: in the liquid line, before the expansion valve. If a sight glass is installed after it, saturation of the filter drier can be seen visually.
• Advantage of the flare connection: no brazing — it can be removed and replaced during service without cutting the line. The flare gasket must be renewed at each replacement.
• ⚠️ Do not open the packaging until the moment of installation. The molecular sieve starts absorbing moisture in open air; a core opened too early is saturated before it is even installed.
• After a compressor burnout the filter drier must always be replaced; if acid cleanup is required, the DCL version is preferred.
• Reading the code: D=drier · M=100% molecular sieve (C would mean 80% + 20% alumina) · L=liquid line · 30=30 in³ · 6=3/4" connection (multiples of 1/8 inch) · no s at the end = flare; with it, solder.
• Size siblings: DML 304 (1/2" flare) · DML 305 (5/8" flare) · DML 306S (same 3/4" size, solder version).

Technical document: Danfoss DML/DCL hermetic filter drier datasheet (PDF, EN, AI192386435941en-001401)