BURKERT 20112850 Type 8640 is a modular pneumatic valve island designed for compact automation assemblies, built on an 11 mm station-width platform in hardware Revision 3 (REV3). The unit is factory-configured with a mixed valve population of 3/2-way functions, G 1/4 pneumatic supply ports, and bottom-facing push-in D6 working ports. Electrical actuation is managed via discrete single wiring without internal fieldbus hardware, providing straightforward integration into conventional I/O control systems.

Hardware article 20112850 incorporates a pneumatic HotSwap shut-off valve on supply port 1 (P) and integrated non-return check valves (RSV) inside exhaust channels 3 (R) and 5 (S). These mechanical features allow individual pilot valves to be replaced during live plant operation while preventing pressure surges or cross-exhaust interference among neighboring valve slices. The valve terminal mounts directly to standard EN 50022 DIN rails and carries an IP20 ingress protection rating.

Technical Data and Operating Parameters

Parameter	Specification (Article 20112850)
Valve Island Type	Type 8640
Hardware Generation	Revision 3 (REV3)
Station Width	11 mm
Valve Population	Mixed valve population (3/2-way functionality)
Operating Pressure Range	2.5 bar to 10.0 bar (overpressure to atmospheric pressure)
Flow Rate ($Q_{Nn}$)	200 l/min to 300 l/min (flow reduced by approx. 20% with HotSwap P shut-off)
Operating Medium	Compressed dry air (lubricated or unlubricated), neutral gases
Air Quality Standard	ISO 8573-1:2010, Class 7.4.4 (5 µm filtration recommended)
Medium Temperature	0 °C to +50 °C
Ambient Temperature	0 °C to +55 °C
Storage Temperature	-20 °C to +60 °C
Operating Voltage	24 V DC (±10% voltage tolerance, max. 1 Vss residual ripple)
Power Consumption per Valve	0.8 W (single 3/2-way valve) / 2 x 0.8 W (double valve with power reduction)
Operating Mode	Continuous operation (100% duty cycle)
Protection Class	III according to VDE 0580
Ingress Protection	IP20 (IP65 inside closed control cabinet)
Supply Port 1 (P), Exhaust 3 (R), 5 (S)	G 1/4
Working Ports 2 (A), 4 (B)	Push-in connector D6 (Ø 6 mm, bottom position)
Valve Body Material	Polyamide (PA)
Seal Materials	FKM, NBR, and PUR
Mounting Type	DIN-rail installation (EN 50022 35 x 7.5 or 35 x 15)

REV3 Platform Features

Revision 3 of the Type 8640 11 mm valve island introduces standardized valve interfaces and improved pneumatic efficiency over earlier hardware revisions:

• Working Port Arrangement: The push-in connection channels on the basic pneumatic module feature a wavy spatial arrangement, replacing the parallel layout used on REV1 and REV2 modules.
• Release Ring Color: Hose quick-release collars on REV3 push-in fittings are molded in blue, whereas REV1 and REV2 versions feature black release rings.
• Reduced HotSwap Pressure Drop: The integrated P-shut-off mechanism in REV3 limits flow rate reduction to approximately 20%, compared to a reduction of up to 50% in REV1 and REV2.
• Standardized Flange Pattern: The single pilot valves (Type 6524 and Type 6525) use a standardized FM20 flange pattern on REV3 base modules.

Integrated HotSwap and Check Valve Protection

The P-shut-off mechanism on supply duct 1 (P) isolates pressure from the selected station during servicing, enabling hot swapping of solenoid valves without depressurizing the entire pneumatic manifold. Integrated check valves in ducts 3 (R) and 5 (S) prevent backpressure pulses from triggering inadvertent actuator motion.

Mechanical Design and Station Assembly

The pneumatic manifold is composed of modular polyamide blocks locked together with built-in snap connectors. Working lines exit through the bottom face of the base modules, maintaining a compact cabinet footprint.

Element No.	Assembly Component	Functional Description
1	Pneumatic connection module, left	Houses primary supply and exhaust thread connections (G 1/4)
2	Basic pneumatic modules	4-fold blocks accommodating D6 push-in ports, HotSwap seats, and RSV valves
3	Pneumatic connection module, right	Closes pneumatic manifold channels or provides secondary supply feeds
4	Pilot solenoid valves	Type 6524 3/2-way rocker/flipper valves secured by two M2 screws

Dimensions and DIN-Rail Installation

BURKERT 20112850 is engineered for standard DIN-rail mounting inside electrical enclosures or decentralized pneumatic control cabinets.

DIN-Rail Installation Steps

1. Position the upper groove of the valve block mounting bracket onto the top edge of the standard rail (EN 50022 35 x 7.5 or 35 x 15).
2. Snap the lower clamping brackets over the bottom rail edge until the locking tabs fully engage.
3. Tighten the clamping piece fastening screws to secure the valve island against lateral vibration.
4. When disassembling, loosen the clamping screws approximately 4 turns and lift the assembly upward off the rail.

Pneumatic Tube Requirements and Handling Guidelines

Push-in connections comply with ISO 14743:2020. Strict adherence to tubing dimensions and insertion procedures ensures leak-free operation up to the rated 10 bar limit.

Tubing Material	Outside Diameter (OD)	Permissible OD Deviation	Minimum Tensile Holding Force
Polyamide (PA)	6 mm	±0.08 mm	120 N
Polyurethane (PU)	6 mm	±0.10 mm	100 N

Tubing Installation Practice

• Cut pneumatic tubing exactly at 90° using a dedicated pipe cutter. Diagonal cuts compromise seal engagement and decrease pull-out retention force.
• Ensure tubing hardness meets a minimum rating of 40 Shore D according to DIN 53505 / ISO 868.
• Push the tubing firmly past the internal gripper ring and into the internal stop of the D6 connector.
• For softer polyurethane lines under cyclic flexure, insert support sleeves (ID 20099400) into the tube ends prior to connection.

Electrical Single Wiring

Article 20112850 operates with parallel discrete wiring rather than an integrated serial fieldbus module. Each pilot solenoid connects directly via individual stranded conductors, making it suitable for direct interface with PLC digital output modules.

• Supply Voltage: 24 V DC (±10% allowable voltage fluctuation).
• Switching Duty: 100% continuous duty cycle (ED).
• Coil Power Rating: 0.8 W per pilot solenoid valve.
• Manual Override: Each valve features an integrated mechanical manual override. To actuate manually, turn the override screw 90° clockwise until it locks; return to the 0° position before initiating electrical operation.

REV3 11 mm Replacement Valves and Spare Components

Item	Description	Packaging Content	Article No.
1	Type 6524 3/2-way NC valve, DN 4.0, 2.5-10 bar, 24 V DC (REV3, FM20)	1 piece	20029918
1	Type 6524 3/2-way NO valve, DN 4.0, 2.5-10 bar, 24 V DC (REV3, FM20)	1 piece	20029919
1	Type 6524 2 x 3/2-way NC valve, DN 4.0, 2.5-10 bar, 24 V DC	1 piece	186260
2	Cover plate for unused valve slot (Type 6524/6525 REV2/REV3)	1 piece	661092
3	Spare valve seals FM20 (for Type 6524 double valve)	12 pieces	20016305
3	Spare valve seals FM24 (for Type 6524 single valve)	12 pieces	20024336
4	Spare module seals for Type MP16 basic pneumatic module	4 pieces	20024339
5	Supply unit right, Type 8640, 11 mm, G 1/4	1 piece	20040351
5	Supply unit left, Type 8640, 11 mm, G 1/4	1 piece	20040352
6	Pneumatic base unit 4-fold, 11 mm, D6, FM20 flange, HotSwap, RSV	1 piece	20040335
-	Cover for unused electrical connection slot	1 piece	653670

Troubleshooting

Fault Observed	Probable Cause	Remedial Action
Solenoid valves fail to switch	Missing or insufficient 24 V DC supply voltage	Check power wiring and verify voltage at terminal matches 24 V DC ±10%
	Manual override locked in engaged position	Rotate manual override 90° counter-clockwise to zero position
	Operating air pressure below 2.5 bar	Verify main supply delivers between 2.5 bar and 10 bar at port 1 (P)
Delayed valve actuation or continuous exhaust blow-off	Upstream air volume restricted by undersized supply lines	Increase supply line diameter and verify pressure drop during multi-valve cycling
	Block pressurized while valves are in energized state	De-energize all coils prior to applying primary pneumatic pressure
	Silencer on exhaust duct 3/5 clogged	Clean silencer element or replace with high-flow exhaust silencer
Manifold block leakage between slices	Damaged, pinched, or missing O-rings between basic modules	Disassemble sub-modules, inspect MP16 profile seals, and replace damaged O-rings