BURKERT 20070440 (Type 8640 revision 3) is a modular pneumatic valve island configured with an 11 mm station width and designed for DIN-rail mounting. Operating within a pressure range of 2.50 to 10.00 bar, the unit provides pneumatic automation control for filtered compressed air and neutral gases across medium temperatures from 0 °C to 50 °C and ambient temperatures from 0 °C to 55 °C. The manifold features G 1/4 supply connections, D6 bottom-oriented working ports on the pneumatic module, integrated check valves in exhaust ports 3 (R) and 5 (S), and pneumatic HotSwap capability in supply port 1 (P). It operates with single wiring without internal bus communication and provides an IP20 degree of protection.

Device Design and Valve Structure

The valve island utilizes Type 5470 pilot-controlled solenoid valves mounted on modular base modules. Each valve assembly integrates a Type 6106 3/2-way pilot valve, valve body with diaphragm, seat seals, connection plates, and a lockable manual override.

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

Manual Override

To operate the valve manually, press the manual override down and turn it 90° clockwise until it stops. The mechanism locks into place and does not reset automatically.

WARNING

Only operate the manual override when electrical power is switched off. Unlock the manual override to restore standard electrical control before system start-up.

Connection Port Assignment

Connection Number	Designation
1	Pressure port (P)
2 and 4	Working ports (B and A)
3	Exhaust port (R)

Circuit Functions and Valve Configuration

Type 8640 accommodates mixed valve population. Valves can be configured for specific circuit operations or converted between functions:

• Circuit Function C (3/2-way valve): In the rest position, pressure port 1 (P/NC) is closed, and working port 2 (A/OUT) vents through port 3 (R/NO).
• Circuit Function D (3/2-way valve): In the rest position, pressure port 1 (P/NO) communicates with working port 2 (B/OUT), while port 3 (R/NC) is closed.
• Circuit Function G (4/2-way valve): In the rest position, pressure port 1 (P) connects to working port 2 (A), and working port 4 (B) vents through port 3 (R).

Conversion from 4/2-Way to 3/2-Way Function

A 4/2-way valve can be converted to 3/2-way operation by closing one of the working ports with a dedicated stopper.

Port 2	Port 4	Resulting Circuit Function
Closed	Open	Function C (3/2-way NC)
Open	Closed	Function D (3/2-way NO)

Technical Specifications

Parameter	Value
Operating medium	Filtered compressed air (particle size max. 10 μm, unlubricated or lubricated), neutral gases (5 μm filtering)
Operating pressure range	2.50 bar to 10.00 bar (pilot pressure must be at least 70% of operating pressure)
Minimum pressure difference	2 bar between port 1 and port 3
Medium temperature	0 °C to +50 °C (below 0 °C operation restricted to dried air)
Ambient temperature	0 °C to +55 °C
Seal material	NBR
Supply connection	G 1/4
Working ports	D6 push-in connectors, bottom-oriented
Electrical connection	Cable plug Type 2516 (DIN EN 175301-803 Form C)
Voltage tolerance	±10%
Degree of protection	IP20 base island; IP65 when fitted with sealed cable plug Type 2516
Integrated features	Check valves in 3 (R) and 5 (S); HotSwap in 1 (P)

INFO

For functional reliability during continuous operation, Burkert recommends triggering at least 1 to 2 switching cycles per day during extended idle times.

Mechanical Assembly and Installation

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

Block Assembly Procedure

1. Begin assembly from the left connection module.
2. Verify that each module is equipped with 2 O-rings in the pneumatic channels. Lightly oil or grease all O-rings before interlocking.
3. Engage the lower latch hooks of the adjacent module into the latch grooves of the preceding module, ensuring seal placement is undisturbed.
4. Press the module upward slightly and engage the upper latch hook.
5. Place 3 O-rings into the rear recesses of the valve body and fasten each valve to the base module using 2 screws tightened to 0.6 ±0.1 Nm.

DIN-Rail and Wall Mounting

• Standard Rail (EN 50022 - 35 x 15 or 35 x 7.5): Hook the upper groove of the valve block into the top edge of the DIN rail, push the lower clamping pieces onto the rail until seated, and tighten the clamping screws.
• Wall Mounting: Secure the block directly to the mounting surface using M4 screws.

Rotating the Solenoid Coil

The solenoid coil can be rotated 180° on the valve body to suit space constraints:

1. Loosen the M2 screw and withdraw the coil from the valve body.
2. Rotate the coil 180°, reseat it onto the body, and fasten the M2 screw in two progressive stages:
   • First stage: 0.1 Nm (±0.05 Nm)
   • Second stage: 0.2 Nm (±0.05 Nm)

DANGER

Ensure the protective earth contact of the coil is firmly connected to the valve body. Verify electrical continuity between the ground pin and the valve body before applying voltage.

Threaded Connection Tightening Torques

Port Size	Function	Recommended Torque [Nm]	Maximum Torque [Nm]
G 1/4	Supply port P, exhaust R/S	4 to 7	20
G 1/8	Supply P, exhaust R/S, outlets A/B	3 to 6	7

Pneumatic and Push-In Fitting Installation

Ensure supply lines are flushed clean before connection. Push pneumatic tubing into the D6 push-in connectors until it seats against the internal stop.

Tubing Requirements

• Material hardness: Minimum 40 Shore D according to DIN 53505 / ISO 868.
• Outer diameter: Compliant with DIN 73378.
• Preparation: Tubing must be cut square, deburred, and free of scratches or longitudinal scores.

Push-In Connector Retention Force (ISO 14743:2020)

Hose Outer Diameter (OD)	3 mm	4 mm	6 mm	8 mm	10 mm	12 mm	14 mm	16 mm
Min. Tensile Force (PA tubing) [N]	60	70	120	170	250	300	300	350
Min. Tensile Force (PU tubing) [N]	25	50	100	150	200	200	250	300

TIP

If retention issues occur with softer polyurethane tubing, insert support sleeves (ID 20099400) into the tube end to reinforce joint sealing and mechanical retention.

Electrical Installation

The unit is wired individually using cable plug Type 2516 (or DIN EN 175301-803 Form C connectors). Fasten the cable plug retaining screw to a maximum torque of 0.3 Nm, ensuring the flat seal is properly compressed.

Test Parameter	Specification Limit
Protective conductor resistance	Maximum 0.1 Ω
Test voltage	12 V
Test current	1 A

Impulse Coil Configuration

For bistable impulse coil variants, maintain a pulse duration of at least 50 ms and observe coil polarity markings:

Pin Polarity	Pilot Valve State	Effect (WWG)	Effect (WWC)
(+) on Pin 2, (-) on Pin 1	Pilot valve opens	1 connects to 3, 2 connects to 3	1 connects to 4
(+) on Pin 1, (-) on Pin 2	Pilot valve closes	1 connects to 2, 4 connects to 3	4 connects to 3

Commissioning and Troubleshooting

Prior to initial power-up, confirm the following steps:

• Verify that supply pressure is at least 2.5 bar and does not exceed 10.0 bar.
• Ensure pressure connection 1 and exhaust connection 3 are correctly routed and not transposed.
• Unlock manual overrides by turning them counter-clockwise back to the neutral operating position.

Symptom	Probable Cause	Corrective Action
Valves fail to switch	Operating voltage absent or out of tolerance	Check power supply and wiring against type label rating.
	Manual override locked in manual state	Turn override mechanism 90° back to the zero position.
	Supply pressure insufficient (< 2.5 bar)	Increase upstream regulator capacity; maintain ≥ 2.5 bar.
Delayed switching or continuous venting	Supply volume inadequate	Ensure unrestricted supply pipe cross-section.
	Valves energized prior to pressure build-up	Pressurize manifold before applying electrical control signals.
	Silencer clogged or undersized	Clean or replace silencer; reduce back pressure.
	Particulate contamination in pilot or seat	Cycle exhaust ports with pressure pulses or replace valve unit.
Leakage between valve modules	Missing or pinched O-rings	Disassemble block, inspect seals, replace damaged O-rings.

Disassembly and Environmental Disposal

1. Pneumatic Depressurization: Disconnect pressure source and vent all residual air from supply and working lines.
2. Electrical Isolation: Disconnect electrical plugs and secure circuits against accidental re-energization.
3. Hose Line Removal: Press the push-in release ring collar inward and pull tubing straight out.
4. Manifold Removal: Loosen DIN-rail clamp screws (approx. 4 turns) and lift the assembly upward from the rail.
5. Module Separation: Insert a flat-head screwdriver into the front disassembly slot to disengage the upper latch hook, then separate modules laterally.

Store the unit in a clean, dust-free environment between -40 °C and +55 °C with all port caps fitted. Dispose of electrical modules and plastic components in accordance with WEEE directives and local electronic waste regulations.