BURKERT 20079259 (Type 8647 AirLINE SP) is a modular electropneumatic automation system factory-configured as a 28-bank valve island. The system integrates 28 monostable 5/2-way pilot valves (Circuit Function H) with an 11 mm station width onto modular pneumatic base sub-bases. Primary compressed air supply and dual exhaust ports are sized at G 1/4, while working connections 2 (A) and 4 (B) are routed through D6 mm push-in couplings on the bottom face of each pneumatic base module. The assembly is built to hardware Generation Revision 2 (REV.2), featuring standardized FM20 fluidic flange profiles and wavy working port tube connector arrangements.

Type 8647 interfaces directly with Siemens distributed I/O systems SIMATIC ET 200SP and SIMATIC ET 200SP HA via the backplane bus, enabling unified engineering within Siemens STEP 7 Classic, TIA Portal, or PCS 7 environments. Because the 28-bank layout exceeds 24 valve functions, this assembly includes one factory-installed intermediate feed unit (PSU-M, 33 mm width) to maintain uniform pressure across all pneumatic stations without line-starvation during concurrent switching.

Technical Data

Product Property	Technical Specification
Model / SKU	20079259
System Type / Revision	Type 8647 / Revision 2 (REV.2)
Number of Valve Slots / Functions	28 valve slots / 28× 5/2-way valve function H (CF H)
Width per Station	11 mm
Intermediate Air Feed	1 PCE (PSU-M, 33 mm width, G 1/4)
Pressure Range	2.5 bar to 10.0 bar (gauge overpressure)
Nominal Flow Rate $Q_{\text{Nn}}$ (Air)	300 l/min (measured at +20 °C, 6 bar inlet, 1 bar $\Delta p$)
Operating Medium	Dry compressed air, lubricated or unlubricated; neutral gases
Compressed Air Quality	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
Operating Voltage	24 V DC (±10%, SELV/PELV, residual ripple 2.4 Vss)
Nominal Power per Valve	0.8 W (Type 6525 pilot valve)
Nominal Current per Valve	40 mA inrush, 28 mA holding current after 120 ms
Operating Duty Cycle	100% continuous operation (100% ED)
Degree of Protection	IP20 (verified by Bürkert; IP65 in closed control cabinet)
Protection Class	III according to DIN EN 61140, VDE 0140
Installation Mounting	DIN rail mounting in industrial control cabinets

Modular System Architecture

Type 8647 AirLINE SP combines connection units, pneumatic base modules, electronic base modules (PQ modules), and pilot valves into a unified electro-pneumatic block.

Connection Units (PSU)

Pneumatic supply, exhaust ventilation, and mechanical DIN rail anchoring are handled by connection units located at the left, center, and right of the valve island:

• PSU-L (Left Connection Unit, 44 mm): Provides central load power status display via the green "PWR OK" LED, supply connection 1 (P), exhaust connections 3 (R) and 5 (S), and auxiliary pilot control port X.
• PSU-M (Intermediate Feed Unit, 33 mm): Installed within the valve line-up to supply supplementary air feed G 1/4 after 24 valve functions. It prevents line starvation when multiple 5/2-way actuators switch simultaneously.
• PSU-R (Right Connection Unit, 44 mm): Closes the pneumatic supply galleries and provides auxiliary exhaust and mounting stability on the standard rail.

Valve Units (PQ Modules and Base Blocks)

Each valve unit consists of three interlocking sub-assemblies:

1. Electronic Base Module (PQ Module): Houses valve driver electronics, short-circuit proof output drivers, channel status LEDs, a DIAG status LED, and a graphical LC display.
2. Pneumatic Base Module: Four-slot or eight-slot sub-base block manufactured from PA/PC that routes supply duct 1 (P) and exhaust ducts 3/5 (R/S) to the individual valve stations while presenting push-in D6 working ports.
3. Type 6525 Solenoid Valves: Monostable 5/2-way flipper-piloted valves mounted on the sub-base with two M2 fastening screws.

Revision 2 (REV.2) Architectural Features

BURKERT 20079259 is manufactured to the Revision 2 (REV.2) build standard. Revision 2 incorporates specific physical and pneumatic enhancements compared to first-generation REV.1 equipment:

Distinguishing Feature	Revision 1 (REV.1)	Revision 2 (REV.2)
Hose Release Ring Color	Black	Blue
Working Connection Port Layout	Parallel linear array	Wavy staggered layout
Single Valve Pneumatic Flange	FM14 flange profile	Standardized FM20 flange profile
Type Label Designation	No revision marking	Explicit "Rev.2" inscription
Flow Reduction with P-Shut-off	Up to 50% flow reduction	Max. 20% flow reduction

Flange Interface Compatibility

Single valves with FM14 flange (REV.1) and FM20 flange (REV.2) are mechanically incompatible and cannot be interchanged. When replacing 5/2-way valves on 20079259, select REV.2 valves with FM20 flange patterns (such as Article 20029920 or 20029925).

Siemens SIMATIC Integration

Type 8647 communicates through the backplane bus of the Siemens SIMATIC ET 200SP / ET 200SP HA distributed I/O station. The valve block latches mechanically and electrically directly to the Siemens BaseUnits on the standard mounting rail.

Engineering Tool	Configuration File / Method	ET 200SP Compatibility	ET 200SP HA Compatibility
Any Fieldbus Tool	GSD (PROFIBUS DP) / GSDML (PROFINET IO)	Compatible	Compatible (GSDML only)
SIMATIC STEP 7 Classic	HSP2105 (V5.5 SP4 or higher)	Compatible	Not Supported
SIMATIC TIA Portal	HSP0225 (V14 SP1 or higher)	Compatible	Not Supported
SIMATIC PCS 7	HUP package (V9.0 SP2 or higher)	Compatible (requires HF IM)	Compatible

Station Configuration Limits

• SIMATIC ET 200SP: Maximum of 64 total modules per station (Siemens I/O modules + Type 8647 electronic base modules and connection units), up to 975 mm total station width (excluding interface module). Multiple valve blocks may be installed in a single station, provided a new light-colored BaseUnit (BU...D or BU...D/T) is inserted to isolate potential groups.
• SIMATIC ET 200SP HA: Maximum of 56 total modules per station, up to 1240 mm total station width. Only one Type 8647 valve block may be installed per station, positioned exclusively at the right end of the ET 200SP HA rack. A light-colored BaseUnit with server cover (HSP0293) is mandatory immediately to the left of the valve block.

Safety-Related Shutdown Architectures

Type 8647 provides three distinct electrical shutdown methods for safety applications:

1. F-PM-E Power Module Shutdown (Certified Safety Architecture): The valve island is operated in the potential group of a Siemens fail-safe power module F-PM-E 24VDC/8A PPM ST. In the event of a safety trip, load voltage to all Type 6525 valves is cut off, causing them to return to their de-energized rest position. All Type 8647 modules in the segment must bear the "FC" designation on their front label. To avoid spurious trips or diagnostic faults during automatic test cycles, configure the F-PM-E module parameters:
   • Maximum readback time for dark test and switch-off test: 1.5 ms to 2.5 ms.
   • Maximum readback time for switch-on test: 0.8 ms.
2. EVS Function (External Valve Shutdown): Electronic base modules equipped with the 2-pole EVS terminal allow a potential-free contact (such as a safety relay or ET 200SP RQ module) to interrupt valve load power per module. Logic and display functions remain operational, reporting "EVS active". Cable runs must not exceed 2 m within the same control cabinet.
3. SIA Channel Shutdown: Valves equipped with individual flying leads allow channel-by-channel external de-energization.

Manual Override Safety Precaution

Manual overrides mechanically bypass any electrical safety shutdown. For safety-critical circuits, either select replacement valves without manual override (Article 20029925) or install lockouts to prevent accidental manual operation.

LC Display and Diagnostics

Each electronic base module (PQ module) provides a graphical liquid crystal display and local LEDs to indicate operating conditions:

• PWR LED (Green): Indicates adequate 24 V DC load voltage.
• DIAG LED: Flashes green when awaiting parameterization; flashes red upon active diagnostics.
• Graphical Matrix Display: Displays channel switching status for channels 0 to 3 (or 0 to 7 on 8-slot modules). Shows position feedback status when connected to field limit switches ("Feedback: Upper position reached" or "Feedback: Lower position reached").
• Plain Text Fault Readout: Cycles dynamically through pending diagnostic conditions, including Wire Break Ch. x, Short Circuit Ch. x, EVS active, PROFIenergy active, and Pilot SCC Limit Ch. x.
• Dual Switching Cycle Counters (SCC): Every channel maintains two independent, remanent cycle counters—one for the pilot valve and one for the driven field process actuator. Counters can be monitored and reset via acyclic data records (DS 130, DS 131, DS 132).

Installation and Pneumatic Connection

Cabinet Rail Mounting Clearances

Mount the valve block horizontally or vertically on a standard DIN rail anchored firmly inside a minimum IP54 enclosure. Ensure a minimum clearance of ≥ 5 cm between the upper edge of the valve block and the cabinet ceiling (≥ 8 cm when EVS connectors are utilized) to permit heat dissipation and allow screwdriver access.

Pneumatic Port Identification

• Port 1 (P): Compressed air supply line, G 1/4 thread.
• Ports 3 (R) and 5 (S): Exhaust lines, G 1/4 thread. Exhaust ducts must be equipped with high-flow silencers or vented outside the cabinet.
• Port X: M5 thread for pilot exhaust / auxiliary pilot air.
• Working Ports 2 (A) and 4 (B): Push-in fittings D6 mm on the bottom pneumatic base modules.

Thread Tightening Torques

Connection Port	Marking / Function	Recommended Torque	Maximum Permissible Torque
G 1/4	Supply P/1, Exhaust R/3, S/5	4 to 7 Nm	20 Nm
M5	Auxiliary control air / pilot exhaust	1.0 to 1.2 Nm	3 Nm
M2 Screws	Valve fastening screws	0.25 to 0.30 Nm	0.35 Nm
Rail Screws	Standard rail clamping screws	approx. 1.8 Nm	2.0 Nm

Pneumatic Hose Requirements (ISO 14743:2020)

To prevent leakage or tube release in push-in connections:

• Cut hoses perfectly straight and perpendicular to tube centerline.
• Observe outside diameter (OD) tolerances: D6 mm polyamide (PA) ±0.08 mm; D6 mm polyurethane (PU) ±0.1 mm.
• Minimum tensile holding force for D6 mm tubing: 120 N for PA tubing, 100 N for PU tubing.

Compressed Air Line Assignment

Never interchange supply port 1 (P) and exhaust ports 3/5 (R/S). Exhaust connections must never be blocked or plugged. Insufficient exhaust venting creates backpressure that can cause unwanted switching or sluggish actuator reaction.

Spare Parts and Accessories for REV.2

Position / Component	Description	Content	Article No.
Replacement Valve Type 6525	5/2-way CF H, REV.2, FM20 flange, 24 V DC, with manual override	1 piece	20029920
Replacement Valve Type 6525	5/2-way CF H, REV.2, FM20 flange, 24 V DC, without manual override	1 piece	20029925
Intermediate Supply Unit	PSU-M intermediate feed, 11 mm width, G 1/4	1 piece	20030063
Pneumatic Base Unit	4-fold base module, 11 mm station width, D6 push-in, FM20	1 piece	20040334
Cover Plate	Cover plate for unused valve slots, Type 6524/6525 REV.2	1 piece	661092
Electrical Cover	Cover for unused electrical plug connections	1 piece	653670
Valve Seal Kit	Replacement profile seals FM20 for Type 6524/6525 REV.2	12 pieces	20016305
Module Seal Kit	Replacement intermediate module seals MP16	4 pieces	20024339
Tube Support Sleeve	Support sleeve for flexible D6 PU tubing in push-in fittings	-	20099400