BURKERT 349264 (Type 8640) is a 24-bank modular pneumatic valve island configured with a 19 mm station width and equipped with Type 5470 pilot solenoid valves. The unit integrates pneumatic connection modules and electrical collective wiring into a compact block for direct mounting on EN 50022 standard rails. Operating across a pressure range of 2.0 to 10.0 bar and an operating temperature range of 0 °C to 50 °C, the island features G 1/4 pneumatic supply and exhaust channels alongside D6 push-in working connections positioned at the valve bottom.

System Architecture and Operating Principle

Type 8640 valve islands utilize a systematic modular architecture comprising pneumatic multi-blocks, base rails, and dedicated electrical interface modules. Snap connectors hold the polyamide bodies together securely without external tie rods. Each station on this configuration incorporates a Type 5470 pneumatic valve driven by a Type 6106 rocker pilot valve.

The Type 6106 rocker pilot utilizes an armature with a tilting bearing that pivots within the pilot body to switch pneumatic flow. Because the minimal tilting movement involves no sliding friction, the pilot is non-wearing and requires no initial lubrication.

Item	Designation
1	Pilot valve Type 6106
2	Exhaust port 3 (R)
3	Pressure port 1 (P)
4	Working port 4 (A)
5	Working port 2 (B)
6	Manual override
7	Cable plug interface (Type 2506 / Type 2516)

Port Numbering Conventions

All pneumatic connections on the valve island are labeled numerically according to standard fluid power conventions:

• Port 1: Supply pressure port (P)
• Ports 2 and 4: Working service ports (B and A)
• Port 3: Exhaust port (R)

Manual Override Function

Each Type 5470 valve station includes a mechanical manual override on the actuator body for system commissioning and manual operation during testing.

Manual Override Procedure

To actuate the valve manually, press the manual override pin and rotate it 90° clockwise until it hits the mechanical stop. In this position, the override remains locked and does not automatically reset. Rotate back 90° counterclockwise to disengage before restoring electrical operation. Operate the manual override only when electrical control signals are switched off.

Circuit Functions and Conversion

Type 5470 valves support multiple circuit functions. The primary 4/2-way configuration can be converted into 3/2-way functionality on-site by closing one of the working ports with a dedicated plug.

Desired Circuit Function	Port 2 (B)	Port 4 (A)	Functional Description
Circuit function C (3/2-way NC)	Closed (plugged)	Open	In rest position, pressure port 1 is closed; working port 4 is exhausted to port 3.
Circuit function D (3/2-way NO)	Open	Closed (plugged)	In rest position, pressure port 1 is connected to working port 2; exhaust port 3 is closed.
Circuit function G (4/2-way)	Open	Open	In rest position, pressure port 1 feeds working port 2; working port 4 exhausts through port 3.

Technical Specifications

Specification Parameter	Technical Value
Valve Island Type	8640
Station Width	19 mm (Type 5470)
Slot Capacity	24 valve positions
Operating Pressure Range	2.0 to 10.0 bar
Minimum Pilot Pressure Differential	≥ 2 bar difference between port 1 and port 3
Pilot Pressure Requirement	Must be at least 70% of operating pressure
Air Flow Rate QNn	300 l/min (measured at +20 °C, 6 bar inlet, 1 bar Δp)
Fluid Media	Filtered compressed air (particle size ≤ 10 μm, unlubricated or lubricated), neutral gases (5 μm)
Operating Temperature	0 °C to +50 °C (ambient and medium)
Body / Seal Material	Polyamide (PA) / Nitrile butadiene rubber (NBR)
Supply Connections 1 (P), 3 (R)	G 1/4 female thread
Working Connections 2 (B), 4 (A)	Push-in fittings D6 mm located at valve bottom
Nominal Operating Voltage	24 V DC (±10% tolerance, ripple ≤ 1 Vss)
Nominal Power per Valve	1 W to 2 W (standard 2 W coil)
Electrical Duty Cycle	100% continuous operation (ED)
Electrical Protection Class	Class III according to VDE 0580
Ingress Protection	IP20 (terminal module); IP65 achievable with sealed Type 2516 cable plug

Continuous Operation Reliability

When operating valves under continuous energization or during extended downtimes, perform at least 1 to 2 switching cycles per day to ensure complete functional reliability and prevent seal sticking.

Mechanical Assembly and Installation

The 19 mm pneumatic base system is assembled from modular multi-blocks linked by latching tabs, sealed by internal O-rings, and secured to mounting surfaces.

Item	Component	Item	Component
1	Left connection module	6	Base module (2-fold)
2	Latch tab	7	Exhaust channel 3 (R)
3	Latch hook	8	Supply channel 1 (P)
4	Base module (3-fold)	9	Sealing O-ring
5	Right connection module	-	-

Multi-Block Assembly Procedure

1. Begin assembly with the left pneumatic connection module.
2. Ensure each module interface is equipped with 2 sealing O-rings in the designated channels.
3. Lightly grease or oil all O-rings before assembly.
4. Insert the lower latch hooks of the adjacent module into the lower latch grooves of the preceding module.
5. Press the module upward slightly and engage the upper latch hook into position until fully seated.
6. Insert 3 O-rings into the rear recess of each Type 5470 valve body.
7. Fasten each valve to its base module using two screws tightened to a torque of 0.6 ±0.1 Nm.

Prevent Pneumatic Leaks

Crushed, pinched, or missing O-rings and profile seals between modular blocks cause line leakage. Ensure all seals are seated cleanly in their grooves prior to latching adjacent sections together.

Standard DIN Rail Mounting

To mount the valve island on an EN 50022 standard DIN rail (35 x 7.5 mm or 35 x 15 mm):

1. Hook the upper locating groove of the valve island assembly onto the top flange of the DIN rail.
2. Snap the lower clamping pieces over the bottom edge of the rail.
3. Tighten the clamping screws securely to prevent lateral movement along the rail.

Port Tightening Torques

When installing threaded fittings into the connection modules, observe the following torque limits:

Port Size	Port Function	Recommended Torque	Maximum Torque
G 1/4, NPT 1/4	Supply port 1 (P), exhaust port 3 (R)	4 to 7 Nm	20 Nm
G 1/8, NPT 1/8	Working ports 2 (B), 4 (A)	3 to 6 Nm	7 Nm

Pressure and Fluid Discharge Hazard

High pressure and uncontrolled venting can cause severe physical injury. Depressurize and drain all pneumatic feed lines completely before tightening fittings, disassembling blocks, or performing maintenance.

Pneumatic Push-in Connection Guidelines

Pneumatic push-in connectors conform to ISO 14743:2020. Observe tube specifications to maintain leak-tight joints and retention forces.

• Tubing Hardness: Minimum 40 Shore D in accordance with DIN 53505 / ISO 868.
• Outer Diameter: Manufactured to DIN 73378 (deviation within ±0.1 mm of nominal dimension).
• Tube Preparation: Cut tubing square at 90° with a sharp tool; deburr completely and inspect exterior surface for scratches, kinks, or oval deformation.

Tubing Outer Diameter Tolerances (ISO 14743:2020)

Tubing Material	Tubing Outer Diameter (OD)	Permitted Deviation
Polyamide (PA)	3 to 10 mm	±0.08 mm
Polyamide (PA)	12 to 16 mm	±0.10 mm
Polyurethane (PU)	3 to 8 mm	±0.10 mm
Polyurethane (PU)	10 to 16 mm	±0.15 mm

Minimum Retention Tensile Force

Tube OD Metric	3 mm	4 mm	6 mm	8 mm	10 mm	12 mm	14 mm	16 mm
Tube OD Imperial	1/8"	5/32"	1/4"	5/16"	3/8"	1/2"	-	5/8"
Min. Tensile Force PA (N)	60	70	120	170	250	300	300	350
Min. Tensile Force PU (N)	25	50	100	150	200	200	250	300

When softer or flexible polyurethane (PU) tubing is utilized, install internal support sleeves (Article 20099400) to ensure mechanical stability and seal tightness under pressure.

Electrical Installation

Article 349264 uses a collective socket module (parallel wiring) with screw-type terminals for up to 24 valves, providing a looped-through ground potential and IP20 protection. Total current drawn across the collective connection must not exceed 3 A.

Individual Valve Coil Wiring (Type 2516 Cable Plug)

When individual Type 5470 coils are accessed via Type 2516 cable plugs (DIN EN 175301-803 Form C):

1. Position the flat sealing gasket between the coil body and the plug connector.
2. Fasten the central mounting screw to a tightening torque of 0.3 Nm (maximum 1 Nm).
3. Connect the protective ground conductor.
4. Verify electrical continuity between the coil protective contact and the body (resistance ≤ 0.1 Ω at 12 V / 1 A test current).

Risk of Electric Shock

Failure of the protective earth conductor connection poses an electric shock hazard. Always verify continuity between the coil ground pin and the valve body before energizing the island.

Impulse Coil Configuration (Bistable Switching)

Plug Configuration	Pilot Valve State	Pneumatic Port Path (WWG)	Pneumatic Port Path (WWC)
(+) on pin 2 / (-) on pin 1	Pilot valve opens	1 to 3 / 2 to 3	1 to 4
(+) on pin 1 / (-) on pin 2	Pilot valve closes	1 to 2 / 4 to 3	4 to 3

Polarity and Pulse Requirement

Correct polarity is mandatory for impulse-type coils. Maintain a minimum control pulse duration of 50 ms to ensure positive valve spool transition.

Troubleshooting Guide

Malfunction	Possible Cause	Corrective Action
Valves fail to switch	No supply voltage or operating voltage below 24 V DC ±10%	Verify power supply and wiring on collective terminal block. Ensure nominal voltage reaches coil.
	Manual override locked in actuated position	Disengage manual override and return to 0 (neutral) position.
	Feed pressure insufficient (< 2 bar)	Verify compressed air supply; set main regulator to deliver at least 2.0 bar across all active stations.
Delayed switching or continuous exhaust blow-off	Feed pressure insufficient or pressure drop during multi-valve cycling	Increase upstream line volume and verify upstream air maintenance units can meet peak demand.
	Valves energized prior to pneumatic pressurization	Apply system air pressure to port 1 before transmitting electrical switching signals.
	Excessive back pressure in exhaust lines due to clogged silencers	Clean or replace exhaust silencers on port 3; size exhaust ducts to prevent restriction.
	Particulate contamination inside valve mechanism	Flush pilot and main spool passages with pulsed air; replace contaminated pilot or valve elements.
External leakage at module joints	O-rings missing, displaced, or pinched between modules	Disassemble sub-blocks and install fresh O-rings; verify flat seals between valves and base modules.