Danfoss DML 032S Filter Drier – 023Z455291, 1/4 inch ODF Solder Hermetic Liquid Line Filter Drier

The Danfoss ELIMINATOR DML 032S hermetic liquid line filter drier protects the refrigeration and air conditioning circuit from moisture, acid and solid particles. It does three jobs at once: the molecular sieve retains water, oil hydrolysis and acid formation are prevented because the water is retained, and the 25 μm filter catches abrasives such as metal chips and dirt.

This code 023Z455291 has a 1/4 inch (6.35 mm) ODF solder connection and is manufactured in India.

🚨 1/4 inch or 6 mm? — The Only Thing to Check Before Ordering

Danfoss produces the same DML 032S body with two different socket diameters, and they cannot be told apart from the outside:

A 6.35 mm pipe does not fit into a 6.00 mm socket. Measure the outside diameter of the pipe in your installation; if you are not sure, remember that 1/4 inch and 6 mm are not the same.

🪤 Solder or flare? This product is solder (braze/ODF) — the ends are plain copper tubes, there is no nut. The flare version is a separate code and its length is also different (110 mm; this product is 98 mm).

Official Dimensions

From the DCL/DML 032s dimension drawing in the Danfoss data sheet:

In practical terms: each solder end protrudes 16 mm from the body, and the pipe enters the socket by approximately 7 mm.

Why DML? — Difference from DCL

Danfoss offers two cores in the same body, and the choice is made according to the oil you use:

🪤 Important distinction: The activated alumina in DCL is a polar material, and oil additives are also polar — alumina absorbs the additives and renders them ineffective. Since DML contains no alumina, it does not retain oil additives. DML is preferred in systems using additive-containing POE/PAG oil. It is also approved for oil-free applications.

Moisture Retention Capacity (drops of water)

Flow Capacity (liquid line, kW)

Compatible Refrigerants

R22 · R23 · R32 · R125 · R134a · R290 · R404A · R407A · R407C · R407F · R407H · R410A · R422B · R422D · R438A · R444B · R448A · R449A · R449B · R450A · R452A · R452B · R454A · R454B · R454C · R455A · R463A · R507A · R513A · R515B · R516A · R600 · R600a · R1233zd(E) · R1234yf · R1234ze(E)

🔥 Flammable refrigerant approval: Solder connections below 25 mm are approved by Danfoss for A3 (R290, R600a) and A2L (R32, R1234yf) refrigerants. As this product is a 1/4 inch solder version, it falls within this scope. A3 use is not approved for flare versions — if you are working with a flammable refrigerant, choose the solder version.

Installation

• Orientation is free (vertical, horizontal or inclined) — but the arrow on the body must point in the flow direction. A filter drier installed backwards bypasses the core; protection is lost and the pressure drop increases.
• When brazing, keep the flame away from the body and wrap it with a wet cloth. The ends are copper-plated steel; excessive heat damages the plating.
• After brazing, wait for it to cool and brush off the remaining flux completely — if this step is skipped, corrosion begins.
• Cover exposed steel surfaces, black paint burned by brazing heat and at least 3 cm of the copper pipe with anti-corrosion paint; paint the joints with two coats.
• Brazing is done under nitrogen flow; then a vacuum down to 500 microns is pulled and the system is charged.

When Should It Be Replaced?

• After a compressor burnout — without exception. Acid and carbon enter the circuit. An acid test is performed on the oil; if acid is present, a drier is also installed in the suction line.
• Every time the circuit is opened (compressor or valve replacement, leak repair). Because the filter drier is saturated with moisture, it is not reused.
• When the pressure drop increases. Field symptom: a temperature difference that can be felt by hand between the inlet and outlet of the filter drier, sweating or icing at the outlet — it is clogged.
• When the moisture indicator in the sight glass turns yellow.

If it is not replaced, moisture and oil combine to produce acid; acid eats away the winding insulation, leads to copper plating and ultimately to compressor burnout. Moisture also forms an ice plug in the expansion valve or capillary tube.

Technical Specifications

🪤 The word Denmark on the label is not a contradiction: Danfoss A/S (Nordborg, Denmark) is the owner of the brand and design; the physical production of this code takes place at the Danfoss factory in India. The box and body label read MADE IN INDIA.

Technical document: Danfoss DML / DCL hermetic filter drier data sheet (PDF, English — dimension drawing on page 8)