Classification & Selection — Choosing the Right Air Preparation Unit-News-YUEQING SHENGYUAN PNEUMATIC CO.,LTD.

Air preparation units are not "one-size-fits-all." Selecting the correct type and configuration is critical for system efficiency and cost-effectiveness.

Classification by Configuration & Application:

Configuration	Components	Typical Applications	Key Selection Notes
Full FRL Unit	Filter Regulator Lubricator	General factory automation, machine tools, pneumatic motors.	Default choice for most standard machinery using lubricated air components.
FR Unit (Two-Stage)	Filter Regulator	Clean/oil-free applications, air logic controls, packaging, medical devices.	Used with oil-free cylinders and valves. Often employs finer filters.
Filter Only	Filter (often high-efficiency)	Downstream of dryers, before sensitive instruments (e.g., sensors, cameras).	Pure protection. Pressure is managed elsewhere in the system.
Modular Units	Independent F, R, L blocks	Customizable large systems, central distribution with branch-specific needs.	Offers flexibility in sizing and maintenance. Connected via modular brackets.
Miniature/Integrated Units	Compact F, R, (L) combined	Small machinery, robotics, confined spaces, single valve/actuator control.	Saves space. Flow capacity is generally lower.

Classification by Filter Type & Performance:

General Purpose Filters (5-40 micron): For bulk liquid and particle removal. Standard for inlet protection.

Coalescing Filters (0.01-1 micron): Remove oil vapor and ultrafine aerosols. Essential for instrument air and critical applications.

Adsorbent Filters (Activated Carbon): Remove oil vapor and odors. Final stage for truly oil-free air.

Selection Criteria Checklist:

Flow Requirement (Cv/Kv): Must meet maximum air consumption of downstream devices.

Port Size (NPT, BSPP, etc.): Must match piping. Do not use port size alone to judge flow capacity.

Filtration Level: Match filter fineness to the most sensitive downstream component.

Pressure Range: Regulator must accommodate both supply pressure and required output pressure.

Environment: Consider bowl guards (safety), materials (for corrosion resistance), and auto-drains (for efficiency).

Article 3: Maintenance, Troubleshooting & Advanced Application

Essential Maintenance Schedule

Daily/Pre-Use: Drain filter bowl. Check pressure setting and oil level.

Weekly/Monthly: Inspect for external leaks. Check auto-drain function.

Every 6-12 Months: Replace filter element. Clean lubricator bowl, check-fill valve, and metering needle. Inspect regulator for diaphragm wear.

Troubleshooting Common Issues

Problem	Likely Cause	Solution
Pressure Dropping Under Load	1. Filter element clogged. 2. Regulator undersized (low Cv). 3. Supply pressure inadequate.	1. Replace filter. 2. Install a regulator with higher flow capacity. 3. Check upstream system.
Pressure Creep (Rising)	1. Regulator seat contaminated or worn. 2. Non-relieving regulator type used.	1. Clean or replace regulator cartridge. 2. Replace with a standard relieving regulator.
Excessive Oil Consumption	1. Lubricator drip rate set too high. 2. Excessive air flow/cycling.	1. Re-adjust to 1-3 drops/min during operation. 2. Check for system leaks or duty cycle.
No Oil Mist Output	1. Check valve stuck (bowl not pressurized). 2. Metering valve clogged. 3. Air flow too low to create vacuum.	1. Depressurize, disassemble, and clean. 2. Clean metering valve orifice. 3. Ensure unit is sized correctly for minimum flow.
Water in Downstream Air	1. Filter bowl full. 2. Auto-drain failed. 3. Ambient temperature below dew point.	1. Manually drain. 2. Repair/replace auto-drain. 3. Install a refrigerated or desiccant air dryer upstream.