BURKERT 20150993 (Type 8640) is a 9-bank modular pneumatic valve island designed for pilot control of compressed air and neutral gases. Built with a 19 mm station width architecture, this preconfigured assembly integrates 9 valve positions on modular pneumatic base rails. It utilizes a central G 1/4 pressure supply port (1/P), bottom-facing D6 push-in working connections (2/B and 4/A), and operates within a nominal pressure span of 2.00 bar to 10.00 bar across fluid temperatures from 0 °C to +50 °C. The unit is wired individually without an internal serial bus communication module, providing IP20 protection under DIN-rail mounting conditions.

System Architecture and Solenoid Valve Design

Type 8640 valve islands integrate Type 5470 solenoid valves mounted to pneumatic base rails (such as Type MP05). Each station incorporates a Type 6106 flipper pilot valve, a main valve body equipped with diaphragm and seat seals, connection interfaces, and an integrated mechanical manual override.

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 Type 2506 / 2516 interface

Pneumatic connection channels follow standardized numerical designations across the manifold:

Connection Number	Standard Designation	Manifold Function
1	Pressure port (P)	Primary pneumatic pressure supply channel
2 and 4	Working ports (B and A)	Working pneumatic outlets to actuators (D6 bottom ports)
3	Exhaust port (R)	Primary pneumatic exhaust collector channel

Manual Override Operation

Each valve station is equipped with a mechanical manual override on the pilot body to permit manual actuation during setup or electrical power interruptions.

To lock the valve manually, press the manual override downward and rotate it 90° clockwise until it hits the mechanical stop. The override locks in this position and does not reset automatically. For automated electrical operation, return the manual override to its de-energized zero position.

WARNING

Actuate the manual override only when electrical control power is switched off.

Circuit Functions and Conversion Procedure

Type 5470 valves on Type 8640 manifolds support circuit functions C, D, and G:

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

A 4/2-way valve body can be converted in the field to a 3/2-way function by sealing one of the two active working ports with an airtight stopper:

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

Technical Specifications and Operating Limits

Technical Parameter	Specification / Limit Value
BURKERT Article Number	20150993
Island Type	8640 modular pneumatic valve block
Base Width per Station	19 mm (Add-on dimension 1)
Station Configuration	9-bank (9 valve positions)
Supply Port 1 (P)	G 1/4 internal thread
Working Ports 2/4	D6 push-in fittings, situated at the valve bottom
Operating Pressure Span	2.00 bar to 10.00 bar
Required Pilot Pressure	2 bar to 10 bar (minimum 70% of applied operating pressure)
Required Port Differential	Δp ≥ 2 bar between pressure port 1 and exhaust port 3
Permissible Fluid Medium	Filtered compressed air (particle size ≤ 10 µm, unlubricated or lubricated), neutral gases (≤ 5 µm)
Fluid Temperature Range	0 °C to +50 °C (operation below 0 °C restricted to dried air)
Ambient Temperature Range	0 °C to +55 °C (storage range: -40 °C to +55 °C)
Manifold Seal Material	NBR
Integrated Options	Without check valves in 3(R)/5(S); without pneumatic HotSwap in 1(P)
Mounting Type	DIN-rail installation (EN 50022 35 x 15 or 35 x 7.5)
Electrical Architecture	Single wiring (without internal fieldbus communication module)
Enclosure Rating	IP20

Continuous Operation Reliability

When operating in continuous industrial service, if operation is interrupted, Bürkert recommends cycling the valves 1 to 2 switching operations per day during plant downtime to preserve seat and pilot responsiveness.

Mechanical Assembly and Mounting

Type 8640 valve islands utilize an interlocking modular block design composed of intermediate segments and terminating connection modules.

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 seals

Multi-Block Assembly Rules

1. Begin block assembly starting from the left connection module.
2. Ensure each module interface is fitted with 2 intact O-rings. Lightly grease or oil all O-rings prior to engagement.
3. Engage the lower latch hooks of the adjacent module into the lower latch grooves of the preceding block, verifying that O-rings remain seated without pinch deformation.
4. Pivot the module slightly upward and snap the upper latch hooks firmly into engagement.
5. Verify that the 3 O-rings located in the rear recess of each Type 5470 valve are aligned and undamaged.
6. Secure each valve to its pneumatic base block using two fastening screws tightened to 0.6 Nm ±0.1 Nm.

Prevent Seal Extrusion

Crushed or pinched O-rings and profile seals between base modules cause cross-channel internal leakage or pressure drops.

Rotating the Solenoid Coil

If installation clearances require an alternate coil exit orientation, the pilot solenoid can be rotated 180°:

1. Loosen the M2 retaining screw and withdraw the coil from the valve body.
2. Rotate the coil 180°, reseat it onto the guide body, and retighten the M2 screw in two progressive stages:
   • Stage 1: 0.1 Nm (±0.05 Nm)
   • Stage 2: 0.2 Nm (±0.05 Nm)
3. Verify electrical continuity between the coil protective earth terminal and the valve body.

Manifold Mounting Methods

• Standard DIN-Rail Mounting: Hook the upper mounting groove of the valve island onto the top edge of a 35 x 15 mm or 35 x 7.5 mm rail (conforming to EN 50022). Snap the lower clamping pieces onto the bottom edge and tighten the clamping screws.
• Wall Mounting: Fasten the assembly directly to a flat mounting surface using M4 mounting hardware through the lateral bracket holes.

Threaded Connection Tightening Torques

Port Size	Circuit Designation	Recommended Torque	Maximum Torque
G 1/4 / NPT 1/4	Port 1 (P), Port 3 (R/S)	4 Nm to 7 Nm	20 Nm
G 1/8 / NPT 1/8	Port 1 (P), Port 3 (R/S), Outlets A/B	3 Nm to 6 Nm	7 Nm

Pneumatic Connections and Push-In Fitting Guidelines

• Minimum hose material hardness: 40 Shore D (per DIN 53505 / ISO 868).
• Outer diameter tolerances must comply with DIN 73378 (permissible variance within ±0.1 mm of nominal OD).
• Tubing ends must be cut square (90° right angle), burr-free, and clean.

Tubing Tolerances (ISO 14743:2020)

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

Tensile Test Requirements (DIN ISO 14743:2020)

Hose Outer Diameter (OD)	3 mm (1/8")	4 mm (5/32")	6 mm (1/4")	8 mm (5/16")	10 mm (3/8")	12 mm (1/2")	14 mm	16 mm (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

Soft Tubing Installation

When using flexible polyurethane (PU) tubing subject to retention difficulties, install internal support sleeves (article ID 20099400) inside the hose end to reinforce radial holding power.

Electrical Installation and Commissioning

Model 20150993 utilizes single wiring directly to individual solenoid coils via Form C cable plugs (e.g. Type 2516 or DIN EN 175301-803 Form C).

Item	Designation
1	Profile flat seal
2	Cable plug (Type 2516 or DIN ISO 175301-803 Form C)

• Fasten the cable plug retaining screw to a maximum tightening torque of 0.3 Nm.
• Always connect the protective earth conductor. Protective conductor loop resistance must not exceed 0.1 Ω when tested at 12 V and 1 A.
• Impulse coils require correct electrical polarity and a minimum control pulse duration of 50 ms:
  • (+) on Pin 2 / (-) on Pin 1: Opens pilot valve.
  • (+) on Pin 1 / (-) on Pin 2: Closes pilot valve.

Troubleshooting Matrix

Fault Symptom	Probable Cause	Remedial Action
Valves fail to switch	Absence of operating voltage or supply voltage below tolerance	Check terminal connections; confirm that operating voltage matches coil rating within ±10%.
	Manual override engaged in non-zero position	Return mechanical manual override to its neutral position.
	Insufficient pressure supply or supply flow volume restricted	Verify minimum operating pressure ≥ 2.0 bar across all feeding regulators, maintenance units, and isolation valves.
Valves exhibit switching delays or continuous venting at exhaust ports	Supply pressure deficient or line volume choked	Install larger accumulator/feeder capacity; confirm pressure ≥ 2.0 bar.
	Island not in de-energized home state during initial pressure build-up	Pressurize the pneumatic manifold before applying electrical control switching signals.
	Exhaust restriction or back-pressure from clogged/undersized silencers	Clean contaminated silencers or replace with larger exhaust ports/expansion mufflers.
	Particulate contamination inside pilot stage or spool chamber	Apply pulsed air bursts to exhaust ducts to clear debris; if seats are scored, replace the valve module.
External leakage across valve blocks	Missing, displaced, or pinched inter-module O-rings	Disassemble block segments and replace damaged elastomer O-rings.
	Base plate flat gaskets displaced or missing	Inspect sub-base seating; reinstall or replace flat seal gaskets.

Disassembly, Auxiliary Modules, and Storage

• Pneumatic Disassembly: To disconnect push-in tubing, push the release collar squarely inward against the fitting body and withdraw the hose line.
• Manifold Rail Disassembly: Loosen DIN-rail clamp screws approximately 4 turns, then disengage the manifold upward. To uncouple base modules, insert a flat-head screwdriver into the front disassembly slot to disengage the upper latch hook, then separate sideways.
• Right Connection Module Function: In customized pneumatic circuits, the right connection module can be installed as an intermediate divider to establish multiple isolated pressure stages within a single physical block, or utilized as a secondary pressure supply entry.
• Storage Conditions: Store in a dry, dust-free environment at temperatures between -40 °C and +55 °C. Protect coil electrical pins and pneumatic ports with dust caps.