PWM Control
Burkert Type 8691 control head is designed for decentralised automation of ELEMENT Type 21xx pneumatic process valves. The valve position is registered via a contact-free, analogue sensor element which automatically detects and saves the valve end position using the Teach function during start-up. The integrated pilot valve controls single or double-acting actuators. An optional communication interface, AS-Interface, IO-Link or büS (based on CANopen) can be selected.
The design of the control head and the actuator permits an integrated pilot air duct without external piping. Besides the electrical position feedback, the device status is shown directly on the control head itself through coloured powerful LEDs, even in difficult ambient conditions. The housing is easy to clean and features proven IP protection and chemically resistant materials for use in hygienic processing in the food, beverage and pharmaceutical industries.
General Technical Data
| Feature | Value |
|---|---|
| Body Material | PPS, stainless steel |
| Seal Material | EPDM |
| Cover Material | PC |
| Control Medium | Neutral gases, air (ISO 8573-1) |
| Supply Pressure | 3...7 bar |
| Air Flow Rate | 250 l/min |
| Actuator Series | Type 21xx, actuator ∅ 70/90/130/225 mm |
| Degree of Protection | IP65/IP67 according to EN 60529, 4X according to NEMA 250 |
| Ambient Temperature | -10...+55 °C (with pilot valve), -20...+60 °C (without pilot valve) |
Electrical Data
Without fieldbus communication: 24 V DC
- Operating voltage: 24 V DC ± 25%
- Power consumption: 2 W or 5 W at maximum load
- Output: Max. 100 mA per output
With digital communication: IO-Link
- Operating voltage: 24 V DC ± 25%
- Transmission rate: 230.4 kbit/s
- Port class: A and B
With digital communication: Bürkert system bus (büS)
- Operating voltage: 18...30 V DC
- Current consumption: Max. 120 mA
Approvals and Conformities
- Explosion Protection: ATEX II 3D Ex tc IIIC T135 °C Dc / II 3G Ex ec IIC T4 Gc; IECEx
- North America: cULus certificate (E238179), FM Explosion Protection (Class I, Zone 2)
Materials
| No. | Element | Material |
|---|---|---|
| 1 | Cover | PC |
| 2 | Seal | EPDM |
| 3 | Body casing | Stainless steel |
| 4 | Seal | EPDM |
| 5 | Push-in connector | POM/stainless steel |
| 6 | Basic housing | PPS |
| 7 | Screws | Stainless steel |
| 8 | M12 plug connector | Stainless steel |
Dimensions
Product Connections
M12 circular plug, 8-pin (24 V DC)
M12 circular plug, 5-pin (IO-Link / büS)
Combination Options
A complete TopControl control valve system consists of a positioner Type 8691 and an ELEMENT process valve Type 21xx (e.g., Type 2100, 2101, 2103).
