BURKERT Type 8695 control head is designed for decentralized automation of ELEMENT Type 21xx pneumatic process valves with smaller nominal diameters. The valve position is registered via a contact-free, analogue sensor element which automatically detects and saves the valve end position via the Teach function during start-up. The integrated pilot valve controls single or double-acting actuators.

The design of the control head and actuator is specially configured for the requirements of hygienic process environments and enables internal pilot air duct routing without external piping. In addition to the electrical position feedback, the device status is shown directly on the control head itself via coloured LEDs. An optional AS-Interface communication interface can be selected.

Key Features

• Contact-free inductive valve position registration (Teach function)
• Colour illuminated status display
• Integrated pilot air duct in the actuator
• AS-Interface, IO-Link, Bürkert system bus (büS)
• With ATEX II cat. 3G/D approval

General Technical Data

Property	Specification
Body Material	PPS, stainless steel
Seal Material	EPDM
Cover Material	PC
Setting valve end position	Automatically via teach function or manually
Analogue position sensor	Inductive (contactless) with self-adjusting switching points (PNP)
Stroke range for linear actuator	2.5...32 mm
Control medium	Neutral gases, air, quality class according to ISO 8573-1
Supply pressure	0...7 bar (must be 0.5...1 bar above minimum required pilot pressure)
Pilot air port	Threaded connection G 1/8, stainless steel
Air capacity	7 lN/min (for aeration and ventilation)
Actuator series/size	Type 21xx, actuator ∅ 50 mm
Ambient temperature	-10...+55 °C (with pilot valve), -20...+60 °C (without pilot valve)
Degree of protection	IP65/IP67 according to EN 60529, 4X according to NEMA 250 Standard

Approvals and Conformities

• ATEX: II 3D Ex tc IIIC T135 °C Dc / II 3G Ex ec IIC T4 Gc (BVS ATEX E 008 X)
• IECEx: Ex tc IIIC T135 °C Dc / Ex ec IIC T4 Gc (IECEx BVS 14.0009 X)
• North America: cULus certificate E238179; FM Explosion Protection Increased Safety for Class I, Zone 2.
• CCC: Suitable for import and use for hazardous applications in China.

Dimensions

Electrical Connections

Without fieldbus communication 24 V DC

M12 circular plug, 8-pin

Pin	Description	Configuration
1	Limit switch top	IN 1 (=Top)
2	Limit switch bottom	IN 2 (=Bot)
3	Supply voltage	GND
4	Supply voltage +	24 V DC
5	Valve control unit +	Valve +
6	Valve control unit -	Valve -
7	-	Not used
8	-	Not used

AS-Interface Connection

M12 circular plug, 4-pin

Pin	Description	Pin assignment
1	Bus +	Bus cable AS-Interface +
2	NC	Not assigned
3	Bus -	Bus cable AS-Interface -
4	NC	Not assigned

Product Installation

Combination options with pneumatic ELEMENT process valves

A decentralised, automated valve system consists of a control head Type 8695 and an ELEMENT process valve Type 21xx, actuator size 50 mm.

DANGER

Risk of injury from high pressure in the equipment/device. Before working on equipment or device, switch off the pressure and deaerate/drain lines. Risk of electric shock. Before working on equipment or device, switch off the power supply and secure to prevent reactivation.

Teach Function (Calibrating the end position)

The teach function can be used to automatically determine and read in the end positions of the valve.

NOTE

Breakage of the pneumatic connection pieces due to rotational impact. When unscrewing and screwing in the transparent cap, do not hold the actuator of the process valve but the connection housing.

Chronological description of the teach function:

1. The bottom position is read in internally.
2. The pilot valve switches.
3. The actuator moves automatically to the top position.
4. The top position is read in internally.
5. The pilot valve is turned off.
6. The actuator moves back to the home position.