Emerson Alco 043734 Filter Drier

The Emerson Alco 043734, also identified by model number BFK-165S, is a high-performance bi-directional liquid line filter drier engineered specifically for heat pump applications. This 16-cubic-inch unit features an internal check valve assembly that manages flow and filtration in both heating and cooling modes, eliminating the need for external check valves in reversible refrigeration systems. With a 5/8" sweat ODF connection and a maximum operating pressure of 680 PSI, it is fully compatible with modern high-pressure refrigerants including R-410A, R-22, and R-407C. The solid core desiccant blend—consisting of molecular sieve and activated alumina—is optimized for moisture and acid removal, while the 40-micron filtration pad traps solid contaminants. A corrosion-resistant epoxy powder paint finish ensures long-term shell integrity in demanding environments.

Key Benefits

• Internal check valve design allows for filtration in either direction, simplifying heat pump system piping.
• Solid core desiccant provides maximum moisture adsorption and acid neutralization to protect the compressor from chemical damage.
• 680 PSI high-pressure rating makes this unit safe for use with R-410A refrigeration and high-side liquid lines.
• 5/8" ODF sweat connections ensure a secure, leak-free braze joint for standard line sets.
• Compatible with POE oils and approved for use in HVAC repair and maintenance on HFC and HCFC systems.

Common Questions

Can the BFK-165S be used on straight-cool air conditioning units?
Yes, while designed for bi-flow heat pump duty, this liquid line filter drier can safely be used on single-direction systems, though a standard uni-flow drier may be more cost-effective for those specific applications.

What is the micron rating for the Emerson 043734?
This model provides 40 micron filtration, effectively capturing copper shavings and other debris that can lead to TXV failure or capillary tube blockage.

Is the 043734 compatible with POE oils?
Yes, the Emerson Alco 043734 is fully approved for use with polyolester (POE) lubricants as well as mineral and alkylbenzene oils commonly found in refrigerant piping.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.