BURKERT 20066296 (Type 8640) is a modular pneumatic valve island designed for compact industrial automation, featuring an 11 mm station width per valve slot and Revision 3 (REV3) architecture. The unit integrates a mixed valve population with 3/2-way pilot valve functions, controlled via a multi-pole Sub-D 25-pin electrical connection. Pneumatic supply connections 1 (P), 3 (R), and 5 (S) are configured with G 1/4 threads, while working ports 2 (A) and 4 (B) utilize D6 push-in connectors routed through the bottom of the pneumatic module. Operating within an air pressure window of 2.50 bar to 10.00 bar, the valve island accommodates medium temperatures from 0 °C to 50 °C and ambient operating conditions up to 55 °C, mounted directly to EN 50022 DIN rails with an IP20 ingress protection rating.

Technical Specifications

Technical Parameter	Specification Value
Product Type	Type 8640 Modular Valve Island
Article Number (SKU)	20066296
Generation / Hardware Revision	Revision 3 (REV3)
Width per Station	11 mm
Valve Configuration	Mixed valve population (3/2-way functions)
Supply Connections 1 (P), 3 (R), 5 (S)	G 1/4 threaded ports
Working Ports 2 (A), 4 (B)	Push-in connector D6 (6 mm outer diameter)
Working Port Orientation	Bottom (pneumatic module)
Nominal Operating Pressure Range	2.5 bar to 10.0 bar (overpressure to atmospheric)
Medium Temperature Range	0 °C to +50 °C
Ambient Operating Temperature	0 °C to +55 °C
Storage Temperature	-20 °C to +60 °C
Operating Medium	Lubricated or oil-free compressed dry air, neutral gases (ISO 8573-1:2010 Class 7.4.4; 5 µm filter recommended)
Electrical Interface	Multi-pole Sub-D 25-pin
Operating Voltage	24 V DC (±10% tolerance, max. 1 Vss residual ripple)
Single Valve Power Consumption	0.8 W per single valve (2 × 0.8 W with power reduction for double valves)
Total Multipole Current Rating	Max. 3 A (valve total) + max. 3 A (digital inputs)
Protection Class	III according to VDE 0580
Ingress Protection Rating	IP20 (IP65 achievable when mounted inside closed control cabinets)
Installation Type	Standard rail EN 50022 (35 × 7.5 mm or 35 × 15 mm)
Valve Body Material	Polyamide (PA)
Sealing Materials	FKM, NBR, and PUR
Integrated Check Valves	No (in ports 3/R and 5/S)
Pneumatic HotSwap	No (standard manifold feed)
Digital Inputs	0 PCE

System Architecture and Modular Construction

Type 8640 modular construction allows custom pneumatic and electrical interface grouping. Built-in snap connectors join basic pneumatic modules and electrical slices without requiring separate tie-rods or continuous tensioning hardware.

Item	Modular Element	Component Function
1	Pneumatic connection module, left	Houses main supply and exhaust G 1/4 ports (1/P, 3/R, 5/S)
2	Basic pneumatic modules (11 mm)	Houses D6 bottom working connections (2/A, 4/B) for 2 to 24 valve slots
3	Pneumatic connection module, right	Closes the pneumatic manifold channel or provides secondary supply
4	Pilot valves (Type 6524 / Type 6525)	Mounted onto 11 mm base module stations with 2 screws

Electrical Multi-Pole Connection

Article 20066296 incorporates a multi-pole electrical connection module utilizing a Sub-D 25-pin connector. The multi-pin block routes control signals to individual pilot solenoids while maintaining a looped ground potential across all active stations.

• Signal Capacity: Supports up to 24 individual valve coils on multipole installations.
• Current Capacity: Total valve current is rated at a maximum of 3 A across all energized coils simultaneously.
• Protection: Module electronics provide IP20 contact protection.

Revision 3 Design Characteristics

The Revision 3 (REV3) generation introduces specific mechanical updates compared to earlier REV1 and REV2 versions. These design differences affect spare valve selection and manifold sealing.

Mechanical Feature	Type 8640 REV1 / REV2	Type 8640 REV3 (Article 20066296)
Working Connection Channel Layout	Straight parallel channels	Wavy channel arrangement
Hose Release Ring Colour	Black	Blue
Pilot Valve Flange Standard	FM14 / FM15 interface	FM20 / FM24 standardized interface
Flow Reduction with P-Shutoff Option	Up to 50%	Up to 20%

Revision Compatibility Notice

Pneumatic pilot valves for REV3 feature a standardized pneumatic flange pattern that differs from REV1 and REV2. Replacement valves must be matched by article number to the REV3 generation.

Compatible 11 mm Pilot Valves and Circuit Functions

The 11 mm pneumatic base modules of Type 8640 accommodate Bürkert Type 6524 flipper solenoid valves and Type 6525 pilot valves. Each pilot valve features an integrated manual override as standard.

Circuit Function	Valve Type	Pressure Range	Opening Time	Closing Time	Power	REV3 Article No.
CF C: 3/2-way NC	Type 6524 (DN 4.0 mm)	2.5 ... 10 bar	15 ms	28 ms	0.8 W	20029918
CF D: 3/2-way NO	Type 6524 (DN 4.0 mm)	2.5 ... 10 bar	15 ms	28 ms	0.8 W	20029919
CF H: 5/2-way	Type 6525 (DN 4.0 mm)	2.5 ... 10 bar	20 ms	28 ms	0.8 W	20029920
CF C: 2 × 3/2-way NC	Type 6524 (DN 4.0 mm)	2.5 ... 10 bar	12 ms	20 ms	2 × 0.8 W	186260

All pilot valves listed achieve a nominal flow rate QNn of 300 l/min measured at +20 °C with 6 bar valve inlet pressure and 1 bar differential pressure.

Installation and Pneumatic Connection Guidelines

DIN-Rail Mounting

1. Hook the upper mounting groove of the valve terminal into the EN 50022 standard rail (35 × 7.5 mm or 35 × 15 mm).
2. Snap the lower clamping pieces over the lower DIN-rail flange.
3. Tighten the clamping piece screws securely.

Push-In Fitting Requirements (ISO 14743:2020)

Connecting pneumatic hoses into the D6 push-in connectors requires strict adherence to hose surface tolerances and preparation:

• Hose Material: Polyamide (PA) or Polyurethane (PU) with a minimum surface hardness of 40 Shore D (DIN 53505 / ISO 868).
• Dimensional Tolerances: For 6 mm outside diameter hoses, polyamide tolerances must not exceed ±0.08 mm, and polyurethane tolerances must not exceed ±0.1 mm.
• Preparation: Cut hose squarely at 90° using a hose cutter. Deburr and inspect the exterior surface for scratches, kinks, or flat spots.
• Insertion: Push the hose straight into the connector past the internal O-ring seal until it hits the mechanical stop.
• Tensile Holding Capacity: In accordance with ISO 14743:2020 tensile testing, 6 mm PA tubing must withstand a minimum pull force of 120 N; 6 mm PU tubing must withstand at least 100 N.

Inactive Valve Stations

If specific stations on the basic module remain unequipped with active pilot valves, seal the pneumatic ports using cover plate 661092 and install electrical connection cover 653670 to maintain pressure integrity and contact protection.

Depressurisation Requirement

Before removing hose lines, disassembling module blocks, or replacing pilot valves, completely vent all pneumatic lines and turn off the 24 V DC electrical supply.