Danfoss DMB 163S Bi-Flow Filter Drier – 023Z1476, 3/8 inch ODF Solder, Heat Pump Bi-Flow Filter Drier

Danfoss ELIMINATOR DMB 163S is a hermetic bi-flow filter drier made for the liquid line of air conditioning and refrigeration systems that operate as heat pumps. Thanks to the internal check valves in its shell, the refrigerant passes from the outer surface of the core toward its center whichever direction it comes from; moisture, acid and dirt are retained in both flow directions.

This code, 023Z1476, is the single-box product with a 3/8 inch (9.52 mm) ODF solder connection and a 16 in³ shell. The box and shell label read MADE IN MEXICO.

Why Bi-Flow? — Filter Drier Selection in Heat Pumps

In a heat pump air conditioner, when the 4-way valve switches between heating and cooling, the flow direction in the liquid line also reverses. This changes the filter drier selection:

• A one-way filter drier (e.g. DML) works from the inside of the core outward in reverse flow. It releases the dirt it retained in the previous direction, and the filter function is lost.
• The old solution was to connect two one-way filter driers with two check valves in a bridge arrangement. This layout increases both the number of parts and the number of brazed joints.
• The DMB combines this bridge in a single shell. According to Danfoss, depending on the system type, up to ten brazed joints are eliminated; since every brazed joint is a potential leak point, the risk of leaks also decreases.

When the flow direction changes, the retained dirt is not released; the check valves are insensitive to dirt and show low resistance in both directions.

Official Dimensions

From the DMB/DCB 163s dimensional drawing in the Danfoss data sheet (copper-plated steel solder ends, 08–16 in³ shell); the dimension card is in the 2nd image:

From the same family, the DMB 164S (1/2 inch) and the larger-shell DMB 305S (5/8 inch) are also available on our site.

DMB or DCB? — The Core Difference

The activated alumina in the DCB is a polar material and can also retain oil additives, rendering them ineffective. Since the DMB contains no alumina, it does not deplete oil additives.

Compatible Refrigerants

Danfoss recommends the DMB for all HFO, HC, HFC and HCFC groups. In the field this means: R410A · R32 · R454B · R407C · R134a · R404A · R507A · R22 · R290 · R600a · R1234yf · R1234ze.

Flammable refrigerant note: For flammable refrigerants, Danfoss approves only the versions with solder connections and below 25 mm. As this product has a 3/8 inch solder connection, it falls within this scope; flare versions must not be used with flammable refrigerants.

Liquid Line Capacity

Conditions: ARI 710-86, −15 °C evaporating, +30 °C condensing, 7 kPa pressure drop.

Installation

• The bidirectional arrow (⟷) on the shell shows that the filter drier works in both directions; there is no distinction between inlet and outlet. In a heat pump it is installed in the liquid line between the outdoor unit and the indoor unit, in the common line of the expansion devices.
• When brazing, keep the flame away from the shell and wrap a wet cloth around the shell. The ends are copper-plated steel; excessive heat damages the plating and the internal check valves.
• Brazing is done under nitrogen flow; then the system is evacuated to 500 microns and charged.
• Clean off any flux left after brazing; cover steel surfaces where the paint has burnt with anti-corrosion paint.

When Should It Be Replaced?

• After a compressor burnout — acid and carbon enter the circuit, so the filter drier must be replaced.
• Every time the circuit is opened (replacement of the compressor, 4-way valve or expansion valve, leak repair). A moisture-saturated filter drier is not reused.
• When the pressure drop increases: a temperature difference between the two ends of the filter drier that can be felt by hand, or sweating or frosting at an end, indicates clogging.
• When the moisture indicator in the sight glass changes color.

Technical Specifications

Technical document: Danfoss DMB / DCB bi-flow hermetic filter drier data sheet (PDF, English, 2023.06 — dimensional drawing on page 5)