BURKERT 20017437 (Type 8640) is a 16-bank modular pneumatic valve block configured for 3/2-way valve functions. Built with an add-on station spacing dimension of 33 mm, the assembly incorporates G 1/2 process connections on the primary pressure supply side and G 1/4 pneumatic working ports arranged opposite the supply side. Operating across a nominal pressure range of 2.00 bar to 8.00 bar, the unit handles neutral gases and filtered, compressed dry air between 0 °C and +50 °C.

Designed for integration directly into control cabinets or distribution panels, the unit utilizes single wiring for electrical actuation without an internal bus interface, achieving an ingress protection rating of IP20. Mechanical stabilization is established through integrated DIN-rail clamping compatible with standard EN 50022 mounting rails. The valve block body and intermediate pneumatic segments are fabricated from polyamide, joined via snap-in mechanical connectors to form a rigid pneumatic manifold assembly.

Technical Specifications

Specification Parameter	Value / Execution
Product Model / Identifier	Type 8640 / Article No. 20017437
Total Number of Valve Stations	16-bank (16 valve positions)
Valve Circuit Function	3/2-way valve function
Station Add-on Dimension	33 mm
Pressure Port 1 (P)	G 1/2 female thread
Working Ports 2 (A)	G 1/4 female thread
Working Connection Position	Opposite of supply side
Nominal Operating Pressure Range	2.00 bar to 8.00 bar
Medium Operating Temperature Range	0.00 °C to +50.00 °C
Permissible Ambient Temperature Range	0.00 °C to +55.00 °C
Permissible Storage Temperature	-20.00 °C to +60.00 °C (-40 °C to +55 °C packaged)
Operating Medium	Oil-free or lubricated compressed dry air, neutral gases
Compressed Air Quality Standard	ISO 8573-1:2010, Class 7.4.4 (5 µm filtration recommended)
Electrical Interface	Single wiring (individual parallel stranded connections)
Internal Bus Communication	Without (due to single wiring execution)
Digital Inputs (EME Module)	0 PCE
Nominal Operating Mode	100% continuous duty cycle (ED)
Protection Class	III according to VDE 0580
Ingress Protection Rating	IP20 (with appropriate connectors fitted)
Mounting Standard	DIN-rail mounting according to EN 50022 (35 x 7.5 or 35 x 15 mm)
Manual / Automatic Switching	No
Pneumatic HotSwap at Port 1 (P)	No
Integrated Check Valves in Port 3 (R) / 5 (S)	No
Intermediate Supply Ports	0 PCE

Pneumatic Configuration and Port Execution

The 16-station block configuration routes high-flow pneumatic pilot air through common supply channels within modular polyamide base segments. The central supply port 1 (P) is sized at G 1/2, ensuring uniform volume delivery across all 16 valve banks without requiring intermediate feed plates. Working ports 2 (A) are tapped at G 1/4 and situated on the manifold side opposite the main supply connection to simplify direct panel routing.

Pneumatic module assemblies rely on internal elastomeric sealing profiles to isolate flow chambers between adjacent manifold segments. Compressed air feeding the island must fulfill ISO 8573-1:2010 Class 7.4.4, with filtration recommended to 5 µm or finer to prevent seat contamination.

Single Wiring Execution

Article 20017437 is built specifically for discrete electrical wiring. It does not contain an internal serial bus, gateway interface, or fieldbus coupling module. Solenoids are addressed and switched independently via discrete lines.

Electrical Interface and Control

Article 20017437 uses discrete point-to-point connections where each solenoid station receives independent power and signal lines. The operating voltage is 24 V DC (±10% allowable voltage tolerance, with maximum residual ripple of 1 Vss). Under continuous duty cycle, the coil design maintains stable thermal characteristics when supplied with rated DC power.

Each valve slot features a mechanical manual override mechanism on the pilot valve assembly. To operate the valve manually during dry-cycling or testing, press down the manual override element and rotate it 90° clockwise until it latches. The mechanism remains locked in the active position until manually rotated counter-clockwise back to the neutral zero position.

Operational Restriction

Operate the mechanical manual override only when the electrical supply voltage is disconnected. Unlocking the override back to zero position is strictly required prior to restoring normal automated electrical operation.

Mechanical Construction and DIN-Rail Installation

Manifold bodies are manufactured from injection-molded polyamide (PA), interconnected using interlocking snap-in hooks and matching retaining tabs. The base segments hold the valve modules in alignment while providing rigid anchoring points for DIN-rail attachment.

Standard Rail Installation Procedure

1. Verify that the EN 50022 DIN rail (dimensions 35 x 7.5 mm or 35 x 15 mm) is rigidly mounted to the cabinet backplate.
2. Engage the upper mounting groove of the valve block over the upper edge of the standard rail.
3. Swing the lower assembly inward until the lower clamping elements snap onto the rail flange.
4. Fasten the clamping screws securely to prevent lateral movement along the rail.

Thread Tightening Torque Specifications

When connecting rigid fittings or pneumatic push-in adapters to the female threaded ports, follow standard torque limits to prevent stress cracking in polyamide manifold blocks:

• G 1/2 Connections (Port 1 / P): Recommended torque 4 to 7 Nm; maximum permissible tightening torque must not exceed 20 Nm.
• G 1/4 Connections (Working Ports 2 / A): Recommended torque 4 to 7 Nm; maximum permissible tightening torque must not exceed 20 Nm.
• Valve Body Fastening Screws: Recommended torque 0.6 ±0.1 Nm into the base modules.

Piping Installation Precaution

Never use the solenoid coil or pilot body as a lever arm when tightening threaded process fittings. Seal male threads using PTFE tape or appropriate elastomeric sealing rings without introducing pipe wrench stress to the plastic module housing.

Commissioning, Operation, and Maintenance

Before charging the assembly with compressed air, inspect all line connections, verify that supply lines are blown clear of metal shavings or dust, and confirm that manual overrides are disengaged.

• Pressure differential: Maintain a pressure differential between supply port 1 and exhaust ports of at least 2.0 bar to ensure reliable pilot switching.
• Sub-zero operation: For operating conditions approaching or dipping below 0 °C, use dried air exclusively to prevent moisture condensation and internal freezing.
• Interrupted operation: If continuous operation is halted during system down-times, cycle each valve station 1 to 2 times daily to preserve seal seating and functional readiness.

Troubleshooting Chart

Fault Condition	Probable Cause	Corrective Action
Valves fail to actuate	Insufficient or absent operating voltage	Verify wiring connections; confirm 24 V DC ±10% on active terminals.
Valves fail to actuate	Manual override locked in actuated position	Disengage mechanical lock; return override slot to zero position.
Valves fail to actuate	Supply pressure below 2.00 bar threshold	Increase upstream air pressure; inspect upstream regulators and filter bowls.
Delayed switching or continuous venting at exhaust	Back-pressure build-up from restricted exhaust or clogged silencers	Clean or replace exhaust silencers; inspect exhaust line dimensions.
Delayed switching	Solenoid energized prior to system pressure build-up	Establish pneumatic manifold pressure before applying electrical control signals.
Manifold block leakage	Crushed or missing inter-module O-rings	Disassemble module latching hooks; replace damaged sealing rings and apply grease.
Manifold block leakage	Valve seating seal misaligned	Check flat valve base gasket; re-tighten mounting screws to 0.6 ±0.1 Nm.