BURKERT 20135194 (Type 8640) is a 6-bank modular pneumatic valve block configured with a 33 mm station width, G 1/2 main supply port, and G 1/4 working ports positioned opposite the pneumatic supply side. Built on the Type 8640 modular architecture, this pre-configured assembly uses polyamide (PA) base bodies joined by integrated latching mechanics for rapid assembly and standard DIN-rail installation. Designed for direct individual actuation without internal bus communications or digital fieldbus nodes, article 20135194 delivers localized control across pneumatic pressures ranging from 2.00 bar to 8.00 bar at media operating temperatures from 0.00 °C to 50.00 °C.

Technical Specifications

Specification Parameter	Technical Value / Characteristic
Article Number	20135194
Valve Island System Type	Type 8640
Valve Island Setup	6-bank pneumatic valve block
Station Pitch / Width	33 mm
Main Supply Connection 1 (P)	G 1/2
Working Ports 2 (B) and 4 (A)	G 1/4
Working Port Alignment	Opposite of supply side
Nominal Operating Pressure	2.00 bar to 8.00 bar (overpressure to atmospheric)
Fluid Medium Temperature	0.00 °C to +50.00 °C
Permissible Ambient Temperature	0.00 °C to +55.00 °C
Permissible Storage Temperature	-20 °C to +60 °C (-40 °C to +55 °C in transport packaging)
Modular Variant & Communication	Without bus communication (due to single wiring)
Digital Inputs	0 PCE
Intermediate Supply Feed Quantity	0 PCE
Manual / Automatic Switching	No
Integrated Check Valves (Exhaust 3/5)	No
Pneumatic HotSwap Function	No
Mechanical Installation Mode	DIN-rail mounting (Standard rail EN 50022 35 x 7.5 or 35 x 15)
Ingress Protection Rating	IP20 (max. with suitable connection)
Body Material	High-grade Polyamide (PA)
Operating Medium	Compressed air (ISO 8573-1:2010, Class 7.4.4) or neutral gases

Modular Construction and Mechanical Assembly

Type 8640 valve block assemblies are structured from modular sub-units that interlock mechanically using precision latch tabs and latch grooves. The 6-station pneumatic manifold forms a rigid, leak-tight rail once the modules are locked together.

Item	Designation	Functional Role
1	Left connection module	Pneumatic feed termination and side anchoring
2	Latch tab	Front/top alignment and structural engagement point
3	Latch hook	Lower locking hook engaging preceding module groove
4	Base modules (e.g. 3-fold)	Intermediate pneumatic base carrier for valve stations
5	Right connection module	Right-side end termination and optional supplemental porting
6	Base modules (e.g. 2-fold)	Paired pneumatic base carrier block
7	Exhaust channel 3 (R)	Common venting manifold channel
8	Supply channel 1 (P)	Primary pressurized air delivery conduit
9	O-ring	Module-to-module port sealing ring

Assembly procedure steps:

1. Begin the block assembly starting from the left connection module.
2. Ensure every interlocking module face is fitted with two O-rings. Lightly oil or grease all O-rings before mechanical engagement.
3. Engage the lower latch hooks of the adjacent module into the lower latch grooves of the preceding unit, confirming that O-rings remain seated in their grooves.
4. Pivot and press the module slightly upward until the upper latch hooks snap firmly into position.
5. Place three O-rings into the dedicated rear recesses of each valve mounting surface, ensuring accurate alignment.
6. Secure each valve to the base module using two screws, applying a recommended fastening torque of 0.6 ±0.1 Nm.

Sealing Integrity Warning

Crushed O-rings, twisted profile seals, or contaminated sealing channels will result in unsealed manifolds and continuous pneumatic leakage. Check all elastomeric elements prior to snapping modules together.

Mounting and Port Torques

Article 20135194 is factory-configured for DIN-rail installation. The base profile hooks onto a top edge and secures via clamping mechanisms.

Standard DIN-rail installation procedure:

1. Hook the upper locating groove of the valve block over the top rim of the EN 50022 standard rail (35 x 7.5 mm or 35 x 15 mm).
2. Push the lower section inward until the clamping pieces snap securely onto the lower rail edge.
3. Tighten the fixing screws on the lower clamping elements to immobilize the entire manifold assembly.

When screwing pneumatic fittings into threaded ports, do not exceed maximum permissible torques:

Port Size	Port Marking & Circuit Assignment	Recommended Torque	Maximum Permissible Torque
G 1/4 / NPT 1/4	Supply port 1 (P), Exhaust ports 3 (R) / 5 (S)	4 to 7 Nm	20 Nm
G 1/8 / NPT 1/8	Working ports 2 (B) / 4 (A), auxiliary ports	3 to 6 Nm	7 Nm

Tool Safety Restriction

Never utilize the valve solenoid coil or pilot body as a lever arm when tightening process connections or hose fittings. Always grip the port housing directly with appropriate wrenches.

Pneumatic Supply and Hose Connections

The pilot valves require a minimum internal working pressure of 2.0 bar (up to 8.0 bar max). The differential pressure between supply port 1 and exhaust port 3 must remain at or above 2.0 bar at all times for reliable pilot shifting. Supply media must consist of dry, filtered compressed air adhering to ISO 8573-1:2010 Class 7.4.4 (5 µm particle filtration recommended).

When using push-in hose connectors, the tubing must meet DIN 73378 outside diameter tolerances and have a minimum material hardness of 40 Shore D (DIN 53505 / ISO 868). Hoses must be cut square, burr-free, and inserted fully into the fitting until seated behind the internal retaining claws.

Hose Outside Diameter (OD)	Minimum Tensile Force (PA Hose)	Minimum Tensile Force (PU Hose)
3 mm (1/8" / 3.17 mm)	60 N	25 N
4 mm (5/32" / 4 mm)	70 N	50 N
6 mm (1/4" / 6.35 mm)	120 N	100 N
8 mm (5/16" / 8 mm)	170 N	150 N
10 mm (3/8" / 9.52 mm)	250 N	200 N
12 mm (1/2" / 12.7 mm)	300 N	200 N
14 mm	300 N	250 N
16 mm (5/8" / 16 mm)	350 N	300 N

Hose Retention Optimization

When flexible polyurethane (PU) tubing is utilized under dynamic vibrations or pressure cycling, insert stainless support sleeves (Bürkert ID 20099400) inside the tube ends to reinforce holding stability and prevent wall collapse.

Electrical Wiring and Manual Override

Article 20135194 is built without bus communication and operates using single wiring. Solenoid connections utilize individual cable plugs complying with DIN EN 175301-803 Form C (such as Type 2516).

Single-wiring electrical rules:

• Operating voltage: 24 V DC with a permissible voltage tolerance of ±10% and residual ripple below 1 Vss.
• Fasten cable plug screws to a maximum torque of 0.3 Nm (up to 1.0 Nm on Type 2516 contacts) ensuring the perimeter elastomer gasket sits squarely in its channel.
• Verify earth continuity: protective conductor resistance between coil contact and body must not exceed 0.1 Ω at 12 V, 1 A test conditions.

To actuate the valve mechanically during testing:

1. Ensure electrical control voltage is completely turned off.
2. Depress the manual override actuator button.
3. Rotate 90° clockwise until mechanical resistance stops the turn. The manual override is now locked in the actuated position.
4. Prior to initiating electrical control, rotate 90° counter-clockwise to release the manual lock.

Commissioning and Fault Troubleshooting

Verify supply voltage, operating line pressure (2 to 8 bar), port assignments, and unlocked manual overrides prior to applying power.

Operating Fault	Underlying Root Cause	Corrective Remedy
Valve fails to switch	Operating voltage absent or below ±10% tolerance band	Verify supply voltage on cable terminals according to type label rating.
	Manual override locked in actuated position	Turn override counter-clockwise 90° to reset to neutral zero position.
	Line pressure absent or below 2.0 bar pilot threshold	Establish stable supply pressure (minimum operating pressure ≥ 2.0 bar).
Delayed switching or continuous exhaust blow-off	Upstream supply line restricted or insufficient buffer capacity	Install large-volume air reservoir and remove line restrictions.
	Valves energized during system pneumatic pressure build-up	Apply full pneumatic pressure to the manifold before switching pilot valves.
	Excessive back pressure in exhaust due to clogged silencers	Clean or replace silencer elements; use larger expansion mufflers.
	Particulate contamination within valve body	Apply short pressure pulses to purge contaminants, or replace valve unit.
External leakage around block	Missing, misaligned, or pinched O-rings between modules	Disassemble sub-block and fit fresh, lubricated modular O-rings.
	Valve seat flat gasket damaged or missing	Remove valve screws, insert replacement flat seal, torque to 0.6 Nm.

Disassembly and Safe Maintenance

Residual Energy Hazard

Always isolate and discharge all compressed air supplies, vent all connected pneumatic circuits, and de-energize electrical power prior to commencing disassembly work on the Type 8640 block.

Manifold removal and dismantling procedure:

1. Unplug and label all individual electrical connectors.
2. Press down the release collars on push-in connectors and extract tubing straight outward without twisting.
3. Loosen the lower DIN-rail clamping screws by approximately 4 full turns.
4. Tilt and lift the valve block upward away from the EN 50022 mounting rail.
5. To separate sub-blocks, insert a flat screwdriver blade into the front disassembly slot, unlatch the upper latch hook, and slide the module sideways off its retaining track.