一．Product Introduction
A limit switch (e.g., APL series) is a valve position feedback device widely used in industrial automation systems. It is typically mounted on quarter-turn actuators (e.g., pneumatic actuators for ball/butterfly valves) to detect and indicate the valve’s open/closed status (via mechanical switches or sensors) and transmit electrical signals to remote control systems. It also features a visual indicator (e.g., a color-coded dome) for on-site status monitoring.Common applications include process industries (petrochemical, food, pharmaceuticals), where it ensures valve position accuracy and system safety.
二．Product Features
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Durable & Protective DesignDie-cast aluminum housing (polyester powder-coated) with high corrosion resistance; protection grade up to IP67/IP68 (water/dust-proof), and optional explosion-proof certification (e.g., Ex d II BT6) for hazardous areas.
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Easy Operation & Adjustment“Quick-set” spring-loaded splined cam: No tools required for limit position adjustment; no re-calibration needed after initial setup.
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Dual Feedback Modes
- Mechanical switches: 2× SPDT switches (output on/off signals).
- Visual indicator: Dome-style (0-90° rotation) with color coding (e.g., red = closed, yellow = open).
- Optional: 4-20mA current feedback for continuous position monitoring.
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Versatile InstallationNamur-standard mounting (compatible with most quarter-turn actuators); dual cable entries (e.g., G 1/2″ or NPT 1/2″) for flexible wiring.
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Captive ComponentsCover bolts are captive (prevent loss when opening the housing), enhancing on-site maintenance efficiency.
三．Technical Data
| Item | Specifications |
|---|---|
| Model | APL-210N/APL-410/APL-510N (typical series) |
| Housing Material | Die-cast aluminum (option: 316 stainless steel) |
| Protection Grade | IP67 (standard); IP68 (optional) |
| Explosion-Proof Grade | Ex d II BT6 / Ex ia II BT6 (optional) |
| Temperature Range | -20°C to +80°C (standard); -40°C to +80°C (low-temperature option) |
| Electrical Ratings | 15A @ 125-250VAC; 0.6A @ 125VDC; 0.3A @ 250VDC (mechanical switches) |
| Terminal Capacity | 8 points (0.08-2.5 mm²) |
| Cable Entries | 2× G 1/2″ / NPT 1/2″ / M20 |
| Position Indicator | 0-90° rotation; color-coded (red/closed, yellow/open) |
| Optional Accessories | 4-20mA position transmitter; stainless steel bracket |
四．The main shape and connection size
