BURKERT 363967 Type 8640 is a 14-bank modular pneumatic valve block configured with a 19 mm station width for Type 5470 solenoid pilot valves. Built on polyamide (PA) modular base blocks, this pneumatic assembly integrates a G 1/4 central pressure port and D6 push-in working ports positioned opposite the supply side. Operating across a nominal pressure range of 2.0 to 8.0 bar, the unit is engineered for direct DIN rail mounting in industrial control systems.

This specific configuration functions without an internal bus communication interface, utilizing individual wiring for each valve position. It handles neutral gaseous media and compressed air within a medium temperature window of 0 °C to 50 °C and ambient temperatures from 0 °C to 55 °C, delivering an ingress protection level of IP20.

Technical Specifications

Specification Parameter	Value
Product Type	Type 8640 modular valve block
Article Number (SKU)	363967
Number of Valve Stations	14-bank
Width per Station	19.00 mm
Pressure Supply Port 1 (P)	G 1/4
Working Ports 2 and 4	D6 push-in connectors
Working Connection Position	Opposite supply side
Nominal Pressure Range	2.00 bar to 8.00 bar
Flow Rate Medium Temperature	0.00 °C to 50.00 °C
Operating Ambient Temperature	0.00 °C to 55.00 °C
Operating Medium	Filtered compressed air (particle size max. 10 μm), unlubricated or lubricated; neutral gases (5 μm filter)
Compressed Air Quality	ISO 8573-1:2010, Class 7.4.4
Nominal Operating Mode	Continuous operation (100% duty cycle)
Ingress Protection Class	IP20 (IP65 achievable with Type 2516 cable plug)
Mounting Execution	Standard rail installation (DIN EN 50022 35 x 7.5 or 35 x 15)
Communication / Bus System	Without internal bus communication (single wiring)
Intermediate Feed Modules	0 PCE
Integrated Check Valves	No (in ports 3 [R] and 5 [S])
Pneumatic HotSwap in Port 1	No

Design and Valve Architecture

The Type 8640 19 mm pneumatic block is populated with Type 5470 pilot-operated valves. Each valve body is manufactured from polyamide (PA) with NBR elastomer seals and DN 4.0 mm nominal orifices, actuated by a Type 6106 rocker solenoid pilot mechanism. The armature pivots on a tilting bearing, which eliminates sliding friction, prevents mechanical wear, and operates without baseline lubrication.

Item	Designation	Item	Designation
1	Pilot valve Type 6106	5	Working port 2
2	Exhaust port 3	6	Manual override
3	Pressure port 1	7	Cable plug Type 2506 / Type 2516
4	Working port 4	—	—

Each valve station includes a mechanical manual override for commissioning and service testing. Actuation is achieved by pressing the override actuator and rotating it 90° clockwise until it hits the internal mechanical stop. The override locks in position without self-resetting.

Manual Override Operation

Operate the manual override only when electrical power is switched off. The manual override must be turned back to the zero position and unlocked prior to resuming electrical control.

Type 5470 4/2-way valves can be mechanically configured to function as 3/2-way valves by blanking off individual service ports with a dedicated sealing stopper:

• Circuit Function C (Normally Closed): Port 2 closed, port 4 active.
• Circuit Function D (Normally Open): Port 2 active, port 4 closed.

Operating Reliability in Continuous Duty

If continuous operation is interrupted for extended periods, perform 1 to 2 switching cycles per day throughout the downtime to maintain functional switching reliability.

Mechanical Assembly and Mounting

Type 8640 valve blocks are constructed from modular multi-block segments that lock mechanically via integrated latch hooks and tabs, sealed pneumatically by dual NBR O-rings between adjacent modules.

Assembly sequence for pneumatic base modules:

1. Start assembly from the left connection module.
2. Verify that two O-rings are present and lightly lubricated in each module coupling interface.
3. Engage the lower latch hooks of the adjacent module into the mating latch grooves of the preceding block.
4. Press the joining module slightly upwards and lock the upper latch hook into position.
5. Seat 3 O-rings into the rear recesses of each valve body before fastening it to the base module.
6. Fasten each valve body with 2 screws at a tightening torque of 0.6 ±0.1 Nm.

Sealing Integrity

Crushed, pinched, or missing O-rings and profile seals between modular blocks cause pressure leakage. Confirm exact O-ring alignment before snapping modules together or fastening valves.

The assembled 14-bank block can be secured onto standard DIN EN 50022 rails (35 x 7.5 mm or 35 x 15 mm) or mounted directly to a flat panel wall:

• DIN Rail Mounting: Hook the upper mounting groove of the valve block over the DIN rail edge, snap the lower clamping brackets over the bottom rail flange, and tighten the locking bracket screws.
• Direct Wall Mounting: Fasten the block through the dedicated mounting ears of the end connection modules using M4 fastening screws.

Port Size	Thread Function	Recommended Torque	Maximum Permissible Torque
G 1/4 (NPT 1/4)	Supply 1 (P), Exhaust 3 (R)	4 to 7 Nm	20 Nm
G 1/8 (NPT 1/8)	Outlets 2 (B), 4 (A)	3 to 6 Nm	7 Nm

Pneumatic and Electrical Installation

Pneumatic piping requires clean, calibrated tubing with a minimum hardness of 40 Shore D conforming to DIN 53505 / ISO 868 and outer diameter dimensional tolerances per DIN 73378 (±0.1 mm maximum deviation).

Cut hoses square without burrs and insert them firmly into the D6 push-in connectors until they bottom out against the internal retention claws. Minimum tensile holding forces per DIN ISO 14743:2020 must be observed during mechanical pull checks:

Tube Outer Diameter (OD)	3 mm	4 mm	6 mm	8 mm	10 mm	12 mm	16 mm
Polyamide (PA) Min. Tensile Force	60 N	70 N	120 N	170 N	250 N	300 N	350 N
Polyurethane (PU) Min. Tensile Force	25 N	50 N	100 N	150 N	200 N	200 N	300 N

Electrical Safety

Disconnect all operating voltages before servicing the electrical components. Ensure the protective conductor is connected and continuity exists between coil ground and valve housing (maximum resistance 0.1 Ω tested at 12 V / 1 A).

Single wiring connections interface via DIN EN 175301-803 Form C cable plugs (such as Burkert Type 2516). Fasten the cable plug retention screw to a torque of 0.3 Nm, confirming that the elastomeric flat gasket is seated evenly to maintain IP65 integrity at the coil level.

Maintenance and Troubleshooting

Fault Condition	Probable Cause	Corrective Action
Valves fail to switch	Missing or insufficient electrical supply voltage	Verify line voltage against type label specifications; inspect wiring terminals.
	Manual override locked in engaged position	Return manual override to zero position.
	Supply pressure missing or below operating threshold	Restore supply air volume; ensure line pressure is ≥ 2.0 bar (minimum 70% of operating pressure).
Valves switch sluggishly or exhaust continuously	Inadequate line pressure or restricted flow capacity	Verify upstream regulators, filters, and valves; maintain supply pressure ≥ 2.0 bar.
	Block pressurized while valves were energized	De-energize all coils prior to building system line pressure.
	Exhaust silencer blocked by debris	Clean exhaust silencers or replace with unrestricted larger expansion units.
	Particulate contamination inside valve pilot seat	Blow out exhaust passages with pressure pulses or replace contaminated pilot valve.
Air leakage across valve block	Damaged or missing O-rings between base modules	Disassemble sub-modules and install fresh O-rings (greased).
	Displaced flat seal between valve body and manifold base	Inspect valve seating face; reinstall flat gasket with correct alignment.