BURKERT 20045746 (Type 8647 AirLINE SP) is a modular electropneumatic automation system developed for direct mechanical and electrical integration with the Siemens SIMATIC ET 200SP and SIMATIC ET 200SP HA distributed I/O systems. Configured as a Revision 2 (REV2) 16-bank assembly with an 11 mm station width, this unit houses 16 dual pilot valve slices (Type 6524 2x 3/2-way, Circuit Function C normally closed). It supplies 32 individually actuated pneumatic pilot channels from a compact DIN-rail footprint, routing primary pressure through G 1/4 supply ports and delivering pneumatic output via integrated D6 push-in connectors positioned on the base modules.

Designed for cabinet installation with IP20 enclosure protection (attaining IP65 within sealed control cabinets), article 20045746 holds ATEX and IECEx Zone 2 approvals (Ex ec IIC T4 Gc). It interfaces with Siemens I/O systems directly through the ET 200SP backplane bus, allowing seamless parameterization, visual diagnostics via back-lit liquid crystal displays (LCD) on the electronic base modules, channel-level switching cycle monitoring, and integration into Siemens TIA Portal, STEP 7 Classic, and PCS 7 engineering platforms.

Technical Specifications

Specification Parameter	Technical Value
Article Number	20045746
Type Family	8647 AirLINE SP
Hardware Generation	Revision 2 (REV2)
Number of Valve Stations	16 stations (16-bank configuration)
Width per Station	11 mm
Configured Valve Function	16x (2x 3/2-way) Circuit Function C (normally closed)
Total Actuation Channels	32 independent pneumatic pilot channels
Nominal Pressure Range	2.50 bar to 10.00 bar (overpressure to atmosphere)
Auxiliary Pilot Air (External Supply)	> 2.5 bar (not required for standard 2.5–10 bar variant)
Nominal Flow Rate QNn (Air)	300 l/min (measured at +20 °C, 6 bar inlet pressure, 1 bar Δp)
Operating Medium	Filtered dry compressed air (5 µm filter recommended), neutral gases
Compressed Air Quality Class	ISO 8573-1:2010, Class 7.4.4
Medium Temperature Range	0 °C to +50 °C
Permissible Ambient Temperature	0 °C to +55 °C
Storage Temperature Range	-20 °C to +60 °C
Operating Voltage	24 V DC (±10% allowable voltage tolerance, IEC 61131-2)
Residual Ripple	2.4 Vss max.
Nominal Power per Station	2x 0.8 W (with electronic power reduction)
Nominal Current per Valve Coil	40 mA inrush (28 mA holding current after 120 ms)
Protection Class	Class III according to DIN EN 61140 / VDE 0140
Degree of Protection	IP20 (IP65 in closed control cabinet)
Explosion Protection Rating	ATEX: II 3 G Ex ec IIC T4 Gc; IECEx: Ex ec IIC T4 Gc
Supply Port Connections (1/P, 3/R, 5/S)	G 1/4 female thread
Auxiliary Pilot Connections (X)	M5 female thread
Working Port Connections (2/A, 4/B)	D6 push-in couplings (6 mm outer diameter tubing)
Mechanical Mounting	Standard DIN rail (TH 35-7.5 / TH 35-15)

System Architecture & Revision 2 (REV2) Features

Article 20045746 belongs to the Generation Revision 2 (REV2) series of Type 8647. Revision 2 optimizes the pneumatic base modules, connection units, and valve interface geometries while maintaining identical electrical parameters, physical dimensions, and software configuration files with previous hardware revisions.

Distinguishing Features Between REV1 and REV2

Distinguishing Characteristic	Generation REV1	Generation REV2 (Article 20045746)
Working Connection Port Layout	Linear parallel arrangement	Wavy (offset) channel arrangement
Hose Release Ring Color	Black push-in release rings	Blue push-in release rings
Type Label Revision Marking	No "Rev." text on label	Explicitly labeled "Rev.2"
Flange Interface Standard	Separate interfaces (FM14 for single, FM20 for double)	Standardized unified FM20 pneumatic flange pattern
Flow Restriction with P Shut-Off	Flow reduction up to 50%	Flow reduction limited to approximately 20%

Flange Interface Incompatibility

Single valves configured for REV1 (flange pattern FM14) and REV2 (flange pattern FM20) are mechanically and fluidically incompatible. Replacement valves must match the generation of the installed base modules. The 2x 3/2-way double valves (Type 6524) utilize the FM20 pattern in both revisions, but the physical base block port alignment and clamping geometries must adhere to REV2 spare parts.

Integrated Solenoid Valves: Type 6524 (2x 3/2-Way CF C)

Each station of article 20045746 is populated with a Type 6524 double pilot valve slice. The unit combines two independently actuated 3/2-way normally closed seat valves inside an 11 mm wide housing. Each sub-valve utilizes a Type 6144 flipper pilot solenoid valve driving a pneumatic seat amplifier, ensuring rapid switching times and low power dissipation.

• Circuit Function C (CF C): 3/2-way pilot seat valve, servo-controlled, normally closed at de-energized state.
• Double Valve Arrangement: Two distinct 3/2-way valves per station enable individual control of two single-acting actuators or pilot chambers, doubling functional density to 32 pilot channels over 16 physical stations.
• Integrated Manual Override: Standard push-and-turn mechanism allows manual operation during startup and diagnostic commissioning without bus power.
• Electrical Connection: Dedicated terminal prongs mate directly with the internal socket array of the electronic base module (PQ module).

Valve Parameter	Performance Value
Valve Type	Type 6524 (2x 3/2-way)
Circuit Function	Circuit Function C (normally closed)
Body Material	Polyamide (PA)
Seal Materials	FKM, NBR, and PUR
Orifice Size (Nominal Diameter)	4.0 mm
Flow Rate QNn (Air)	300 l/min
Pressure Range	2.5 to 10 bar
Switching Time Opening	12 ms (according to ISO 12238)
Switching Time Closing	20 ms (according to ISO 12238)
Nominal Power per Coil	0.8 W (with active electronic power reduction)

Siemens SIMATIC Integration & Communication

Type 8647 AirLINE SP interfaces directly with Siemens SIMATIC ET 200SP and ET 200SP HA decentralized peripheral architectures, operating as an integrated electronic and pneumatic block on the standard DIN profile rail.

• Backplane Bus Coupling: Digital control commands, parameter telegrams, channel feedback, and diagnostic records transmit across the native backplane bus via Siemens interface modules (IM 155-6 PN ST/HF/HA or IM 155-6 DP HF).
• Engineering Tools: Integrated through GSD/GSDML device master files, Hardware Support Packages (HSP0225 for TIA Portal, HSP2105 for STEP 7 Classic), or Hardware Update Packages (HUP for PCS 7 V9.0 SP2+).
• Electronic Base Modules (PQ Modules): House status LEDs (PWR, DIAG) and liquid crystal graphic displays indicating valve switching states, actual valve feedback positions, and diagnostic codes.
• Integrated Remanent Counters: Two independent switching cycle counters (SCC) per channel record operations separately for the pilot valve and the connected field process actuator.
• PROFIenergy Support: Enables slot-specific shutdown into energy-saving pause states during system idle periods.

Power Supply Planning with Siemens BaseUnits

To isolate load voltage fluctuations from sensitive automation electronics, install a light-colored Siemens BaseUnit (type code BU...D or BU...D/T) immediately to the left of the Type 8647 valve block. This establishes a separate potential group dedicated to valve load power, ensuring the required 24 V DC ±10% voltage tolerance is maintained under heavy switching loads.

Safety-Related Applications & Shutdown Concepts

Article 20045746 accommodates several distinct levels of electrical and functional shutdown depending on safety requirements:

Safety Rules for Pilot Actuation

De-energizing Type 6524 CF C pilot valves returns them to the safe rest position (closed). Manual overrides bypass electrical control signals; in safety-instrumented architectures, manual overrides must be either physically secured or valve variants without manual override must be deployed. Discharging exhaust air must occur through at least two unobstructed exhaust connections with adequate line cross-sections.

1. Fail-Safe Power Module Integration (Siemens F-PM-E): When operated within the potential group of a Siemens F-PM-E 24VDC/8A PPM ST fail-safe power module, the complete load voltage of the valve island can be shut down safely. All electronic base modules (PQ) and connection units (PSU) in the segment must bear the "FC" designation. Required F-PM-E parameters: maximum readback time for dark test 1.5–2.5 ms; maximum readback time for switch-on test 0.8 ms.
2. External Valve Shutdown (EVS): Optional EVS variants incorporate a 2-pole pluggable screw terminal on the electronic base module. Breaking this potential-free loop immediately de-energizes all valves on that module while preserving display, logic, and fieldbus diagnostics.
3. Channel-Specific Safety Shutdown (SIA): Dedicated valve variants with factory-pressed lead wires permit discrete external connection to upstream safety relays.

Mechanical Mounting & Pneumatic Installation

Type 8647 is delivered fully assembled and calibrated. Install the assembly horizontally or vertically on a low-impedance grounded DIN rail inside an enclosure rated to at least IP54.

Minimum Clearances and Fastening Torques

• Cabinet Upper Clearance: Minimum 5 cm clearance between the top edge of the valve block and the cabinet roof for heat dissipation and tool access (minimum 8 cm if equipped with EVS modules).
• DIN Rail Fastening Screws: Tighten clockwise to approximately 1.8 Nm.
• Pneumatic Supply Connections (G 1/4): Recommended tightening torque 4 to 7 Nm (maximum 20 Nm).
• Auxiliary Air Ports (M5): Recommended tightening torque 1.0 to 1.2 Nm (maximum 3.0 Nm).

Working Connection Assignments

For 2x 3/2-way valves (Type 6524), working air channels are mapped across the pneumatic base modules as follows:

Base Module Position	Valve Type	Working Channel Output
Position 1 (Upper Port)	Valve 1 (Top Sub-Valve)	Port 2 (A)
Position 2 (Lower Port)	Valve 2 (Bottom Sub-Valve)	Port 4 (B)

Push-In Fitting Guidelines (DIN ISO 14743:2020)

Working ports utilize precision D6 push-in connectors. Ensure pneumatic lines are cut square and deburred before insertion. Push tubing firmly past the internal O-ring seal until the internal retaining collet engages securely.

Tubing Outer Diameter	Material	Allowed OD Deviation	Minimum Tensile Holding Force
6 mm (D6)	Polyamide (PA)	±0.08 mm	120 N
6 mm (D6)	Polyurethane (PU)	±0.10 mm	100 N

Spare Parts, Maintenance & Ordering Details

Valve servicing is performed from the front face of the island without disturbing adjacent station wiring or the main DIN-rail bus.

In-Service Valve Replacement

Base modules equipped with pneumatic P shut-off allow live valve replacement under line pressure. When loosening the M2 fastening screws, an initial brief discharge of air occurs until the differential shut-off seal engages, preserving supply header pressure for the remaining 15 stations. Safety glasses must be worn during live servicing.

Core Replacement Components for 8647 REV2

Position / Component Description	Contents / Pack Size	Article Number
Replacement Valve Type 6524 2x 3/2-Way CF C (2.5–10 bar, REV2)	1 piece	204710
Replacement Valve Type 6524 2x 3/2-Way CF C (1–10 bar aux air, REV2)	1 piece	300817
Replacement Valve Type 6524 2x 3/2-Way CF C (no manual override)	1 piece	300818
Base Module Blanking Cover Plate (REV2, 11 mm double valve)	1 plate + screws	661092
Profile Valve Seal Kit FM20 (for Type 6524 2x 3/2-way)	12 seals	20016305
Intermediate Module Seal Kit MP16 (11 mm REV2 base units)	4 seals	20024339
Push-In Connector Cartridge D6 mm Brass (Nickel-Plated)	8 pieces	20024340
Push-In Connector Cartridge D6 mm Stainless Steel 1.4401	8 pieces	20024341