The Burkert Type 8691 control head is designed for the decentralised automation of ELEMENT Type 21xx and CLASSIC Type 20xx 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. Focused on plant wash-down applications, the IP protection of the housing is supported by positive pressure inside the control head.

Technical Data

Property	Value
Body Material	PPS, stainless steel
Seal Material	EPDM
Cover Material	PC
Setting of valve end position	Through automatic or manual teach function
Status display	High performance LEDs (colours individually adjustable)
Communication	AS-Interface, IO-Link, Bürkert system bus (büS)
Position sensor	Inductive (contactless) with self-adjusting switching points (PNP)
Stroke range for linear actuator	2.5...45 mm
Control medium	Neutral gases, air, quality class according to ISO 8573-1
Supply pressure	3...7 bar
Air flow rate	250 l/min (for aeration and ventilation)
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

TIP

The supply pressure applied must be 0.5 to 1 bar above the minimum required pilot pressure of the valve actuator.

Materials

No.	Element	Material
1	Cover	PC
2	Seal	EPDM
3	Body casing	Stainless steel
4	Seal	EPDM
5	Push-in connector Threaded connections G 1/8	POM/stainless steel
6	Basic housing	PPS
7	Screws	Stainless steel
8	M12 plug connector	Stainless steel

Electrical Data & Communication

Without fieldbus communication: 24 V DC

• Operating voltage: 24 V DC ± 25%
• Power consumption: 2 W or 5 W at maximum load on an active digital output
• Output: Max. 100 mA per output

With fieldbus communication: AS-Interface

• Profile: S-B.A.E (AB slave, max. 62 slaves/master)
• Operating voltage: Via ASi power supply 29.5...31.6 V DC
• Max. current consumption: 110 mA

With digital communication: IO-Link

• IO-Link revision: 1.1
• 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/IECEx): II 3D Ex tc IIIC T135 °C Dc / II 3G Ex ec IIC T4 Gc
• North America (USA/Canada): cULus certificate (E238179), FM Explosion Protection (Class I, Zone 2, AEx ec IIC T4 Gc)
• China Compulsory Certification (CCC): Suitable for import and use for hazardous applications in China.

WARNING

When used in explosion-risk areas, observe the separate Ex type label and the additional explosion-related operating instructions. Do not use the device in environments with ignition temperatures lower than specified on the approval label.

Dimensions

Combination Options

A complete TopControl control valve system consists of a positioner Type 8691 and an ELEMENT process valve Type 21xx. You order two components and receive a completely assembled and tested valve.

The Type 8691 can be combined with:

• Type 2100: Pneumatically operated 2/2-way angle seat valve ELEMENT
• Type 2101: Pneumatically operated 2/2-way globe valve ELEMENT
• Type 2103: 2/2-way diaphragm valve with pneumatic stainless steel actuator
• Type 2104: T-diaphragm valve with pneumatic actuator in stainless steel
• Type 2105: Tank bottom diaphragm valve with pneumatic actuator in stainless steel
• Type 2106: Pneumatically operated 3/2-way seat valve ELEMENT