Bürkert Pneumatic Control Unit for Decentralised Automation of Process Valves ELEMENT Type 8690

The pneumatic control unit Type 8690 is designed for decentralised automation of ELEMENT Type 21xx pneumatic process valves. Mechanical or inductive limit switches register the valve position. The integrated pilot valve controls single or double-acting actuators. The design of the control unit and the actuator enables an integrated pilot air duct without external tubings. Besides the electrical position feedback, the status of the device is shown directly on the pneumatic control unit itself. The housing is easy to clean and features proven IP protection and chemically resistant materials for use in hygienic processing, in food, beverage and pharmaceutical industries. Focused on wash down applications, the IP protection of the housing is supported by a positive pressure inside the control head. Combined with Bürkert ELEMENT actuators, the pneumatic actuating system enables spring chamber aeration that avoids actuator chamber contamination from the environment.

Body

PPS

Seal

EPDM

Cover

PC

Setting of valve end position

Manual

Manual override of pilot valve

Yes

Optical position indicator (mechanical)

Yes

Valve spindle, initiator

2...28 mm

Valve spindle, micro switch

7...28 mm

Micro switch

2 x micro switch (24 V DC) or 1 x micro switch only for upper end position

Initiator

2 x inductive proximity switch 3-wire (24 V DC) or 1 x adjustable for lower/upper end position

Pilot valve

24 V DC ± 10 %, residual ripple 10 % DC, power consumption 1 W

Residual ripple

10 %

Power consumption

≤ 1 W

Protection class

III according to DIN EN 61140

Multipole variant

M12, 8-pin

Cable gland variant

M16 x 1.5 (cable Ø 5...10 mm) with screw-type terminals for cable cross sections 0.14...1.5 mm²

Control medium

Neutral gases, air, quality class according to ISO 8573 - 1

Dust content

Class 7 (< 40 µm particle size)

Particle density

Class 5 (< 10 mg/m3)

Pressure dew point

Class 3 (≤ - 20 °C or min. 10 °C below the lowest operating temperature)

Oil content

Class X (< 25 mg/m3)

Air supply filter

Exchangeable

Mesh size

Approx. 0.1 mm

Supply pressure

3...7 bar 1.) 2.)

Pilot air port

Threaded connection G ⅛, stainless steel or push-in connector (pipe Ø 6 mm / ¼")

Circuit function

Single and double-acting

HS Code

8481.80

• Burkert 8690
• Buerkert 8690
• Bürkert 8690
• Type 8690
• Burkert Type 8690