Mainline Compressed Air Filter CJ-020 C

1. Purpose and Operating Principle

The Class C filter (polymer pre-filtration cartridge) traps solid particles 3 µm and larger and reduces residual oil content in the compressed air stream. It is used as the first stage of air preparation — ahead of finer filters (see the “Cartridge Compatibility” section below).

2. Technical Specifications

3. Decoding the CJ-020 C Code

• CJ — mainline filter series (up to 1.6 MPa).
• 020 — body size.
• C — filtration grade (pre-filtration, polymer cartridge).

4. Design Features

• Aluminum alloy body with electrophoretic coating inside and out — enhanced corrosion resistance when operating with condensate.
• Stainless steel cartridge frame with diamond-pattern mesh — mechanical protection for the filter element.
• Built-in differential pressure gauge — visual monitoring of cartridge clogging without extra instruments.
• Condensate drain valve with O-ring seal — built into the filter bowl.

5. Installation Recommendations

1. Mounting orientation. Install the filter strictly vertically, bowl facing down — this ensures correct condensate drainage and separation efficiency.
2. Thread sealing. On the G 3/4″ thread (parallel, BSPP), PTFE tape is not used — use the manufacturer’s sealing rings/gaskets.
3. Service clearance. Leave 100–150 mm of free space underneath for maintenance (unscrewing the bowl, replacing the cartridge).
4. Bypass line. A bypass line is recommended so the filter can be serviced without a full shutdown of the pneumatic system.

6. Cartridge Compatibility

The CJ-020 C housing also accepts finer-grade cartridges from the same line:

• FJ-020 C — pre-filtration, from 3 µm (standard cartridge).
• FJ-020 T — fine filtration, from 1 µm.
• FJ-020 A — ultra-fine filtration, from 0.01 µm.

This lets the same housing serve as the base for a multi-stage air preparation system, with only the cartridge changing.

7. Common Mistakes

• Installing horizontally or with the bowl facing up — disrupts condensate drainage and reduces separation efficiency.
• Using PTFE tape on the parallel G thread — can allow tape fragments to enter the system; use the standard seals instead.
• Ignoring the pressure gauge readings — replacing the cartridge “on a schedule,” without regard to the actual pressure drop, can lead either to premature replacement of a working cartridge or to missing the point when the cartridge is already clogged.
• No service clearance — mounting flush against a wall or other equipment makes it difficult to unscrew the bowl when replacing the cartridge.

8. Applications

• Compressed air lines ahead of pneumatic tools, spray-painting, and sandblasting equipment.
• Industrial compressor stations — the first stage of air preparation ahead of finer filters.
• Contamination-sensitive systems — where preliminary protection against solid particles and oil emulsion is needed ahead of precision equipment.

9. Expert Opinion

Vitalii Boluchevski, lead engineer at Acvatron SRL (18 years of experience): “The Acvatron CJ-020 C mainline filter is a key protective element for any pneumatic system: it traps up to 99% of coarse particles and extends the microfilter’s service life by 2.5–3 times.”

10. FAQ

1. When does the cartridge need to be replaced? Replace the cartridge when the gauge needle enters the red zone or the pressure drop reaches 0.35–0.5 bar, or every 3,000–4,000 operating hours (but at least once every 12 months).

2. Can a finer cartridge be installed in this housing? Yes. The housing is compatible with FJ-020 T (1 µm) and FJ-020 A (0.01 µm) cartridges from the same line.

3. What’s included in the package? A differential pressure gauge and a condensate drain valve.

4. What thread does the filter have? G 3/4″ (parallel, BSPP).

5. Is the filter suitable for piston compressors? Yes, it is stated to resist the pressure pulsations typical of piston compressors.