BURKERT 20093842 Type 6281 is a servo-assisted 2/2-way diaphragm solenoid valve designed for controlling, shutting off, and dosing neutral liquid and gaseous media with a viscosity up to 21 mm²/s. Built as a complete valve assembly in generation EV, it features a DN 20 (3/4 inch) main orifice, internal G 3/4 thread connections, a brass body meeting DIN EN 50930-6 drinking water standards, and EPDM seals certified under the French ACS drinking water standard. The valve operates in normally closed circuit function A, driven by a 24 V AC (50/60 Hz) central screwed coil assembly that delivers vibration-resistant operation and damped, quiet closing.

With an operating differential pressure requirement between 0.2 bar and 16 bar, the valve reaches a water flow factor Kv of 8.5 m³/h and a gas flow rate QNn of 9,100 l/min. The electrical interface conforms to DIN EN 175301-803 Form A, achieving IP65 ingress protection when fitted with a suitable cable plug such as Bürkert Type 2518 or Type 2509. Rated for 100% ED continuous operation across a medium temperature span of -30 °C to +90 °C, the unit is intended for water supply systems, industrial process circuits, and general automation equipment.

Circuit Function & Operating Principle

BURKERT 20093842 operates according to Circuit Function A (CF A). In the de-energized rest state, the valve is closed by spring force and medium pressure acting above the diaphragm. When the solenoid is energized, the plunger opens the 1.3 mm pilot control bore, venting the pressure chamber above the diaphragm toward the valve outlet. Upstream pressure below the diaphragm then lifts the main seal from the seat, establishing flow above the seat.

Minimum Operating Pressure Requirement

Type 6281 is a servo-assisted valve requiring a minimum differential pressure of 0.2 bar between inlet and outlet to function. A differential pressure of 0.5 bar is required to fully open the complete cross-section.

Switching performance measured at +20 °C and 6 bar inlet pressure yields an opening time of 0.1 to 1.5 seconds (pressure drop to 90% of differential flow pressure) and a closing time of 0.2 to 4.0 seconds (pressure build-up to 90% of inlet pressure).

Technical Specifications

Parameter	Value
Valve Type	6281 (Generation EV)
Article Number	20093842
Circuit Function	Circuit function A (2/2-way, NC)
Fluidic Connection Number	2 ports, 2 switching positions
Port Connection 1 & 2	Internal thread G 3/4 (marking 3/4)
Main Valve Orifice (DN)	20 mm (3/4 inch)
Pilot Control Orifice	1.3 mm
Flow Direction	Above seat
Nominal Pressure Rating	PN 16 (DIN EN 1333)
Operating Pressure Range	0.2 bar to 16 bar
Flow Coefficient Kv (Water)	8.5 m³/h (measured at +20 °C, 1 bar Δp)
Nominal Flow Rate QNn (Gas)	9,100 l/min
Wetted Body Material	Brass acc. to DIN EN 50930-6
Seat & Outer Seal Material	EPDM (Ethylene-propylene-diene rubber)
Medium Temperature Range	-30 °C to +90 °C
Max. Ambient Temperature	+55 °C
Actuator Type	Plunger valve (solenoid width 32 mm, AC10)
Operating Voltage	24 V AC (50/60 Hz, AC only)
Voltage Tolerance	±10%
Duty Cycle	100% ED continuous operation
Coil Insulation Class	Class B (polyamide)
Protection Class	IP65 (with cable plug connected)
Installation Length	80 mm
Certifications	ACS (Material-approval-drinking water), CE, EAC

Materials of Construction

No.	Element	Material
1	Solenoid coil	Polyamide (Class B)
2	Stopper	Stainless steel 1.4113
3	Shading ring	Copper (Cu, brass version)
4	Magnetic core (plunger)	Stainless steel 1.4113
5	O-ring	EPDM
6	Core seal	EPDM
7	Core spring	Stainless steel 1.4310
8	O-ring	EPDM
9	Diaphragm	EPDM
10	Diaphragm holder	PPS GF40
11	Valve body	Brass acc. to DIN EN 50930-6

Permissible media for the EPDM seal combination comprise cold and hot water, as well as oil-free and fat-free liquids. Chemical compatibility can be verified through the Bürkert resistApp platform.

Dimensions & Installation Footprint

Dimension Parameter	Value (mm)	Description
Orifice (DN)	20	Main flow diameter
Port Thread (G)	G 3/4	Thread marking G1
Thread Engagement Depth (F1)	16	Female thread depth
Total Body Length (L)	80	Face-to-face installation length
Width Across Flats (SW)	32	Wrench flat dimension on ports
Valve Body Width (E)	37	Body center-to-side dimension
Center Height to Coil Top (A)	99.6	Height from pipe centerline to coil top
Total Height to Plug Top (B)	115.6	Height from pipe centerline including cable plug
Coil Assembly Width (C)	60	Solenoid operator profile width
Coil Length with Plug (D)	74	Clearance required for electrical connector
Base Mounting Offset (N)	10	Bottom clearance dimension
Solenoid Coil Width (H)	32	AC10 coil size 5

Electrical Data & Power Consumption

BURKERT 20093842 is equipped with an AC10 size coil (32 mm width) operating at 24 V AC 50/60 Hz. The coil system provides power consumption values defined in standard operation:

Operating Parameter	Specification
Operating Voltage	24 V AC (50/60 Hz)
Voltage Tolerance	±10%
Inrush Power (AC)	24 VA
Holding Power (AC)	14 VA / 8 W (nominal 16 VA / 7 W)
Electrical Connection Type	Cable plug Form A acc. to DIN EN 175301-803
Recommended Cable Plug	Bürkert Type 2518 or Type 2509 (ordered separately)
Cable Plug Tightening Torque	Max. 1.0 Nm

Installation & Commissioning

Prior to installing the valve into the pipework, purge and clean all pipelines to remove welding residues, swarf, and dirt. A dirt trap (strainer mesh ≤ 500 µm) should be placed upstream of the valve inlet.

Installation Position & Flow Direction

• Mounting position is arbitrary, but orienting the valve with the actuator upright is recommended.
• Observe the flow direction arrow marked on the brass body. Flow must enter port 1 (P) and discharge through port 2 (A).

Pressure and Voltage Hazard

• Switch off pressure and vent the piping system completely before loosening any lines or fittings.
• Disconnect power supply and secure against unintended reactivation before touching electrical terminals.

During mechanical piping installation, hold the valve body firmly using an open-end wrench across the wrench flats (SW 32). Do not use the solenoid coil as a lever arm. Tighten female pipe connections securely without introducing mechanical bending stress to the valve housing.

Solenoid Coil Mounting Precautions

• Connecting the solenoid to an electrical supply without a pre-installed valve core guide tube will cause rapid coil overheating and destruction.
• Tighten the coil retaining nut (1) using an open-end wrench to 5 Nm for AC10 coils (32 mm width). Do not exceed this torque or overtighten.
• Verify the presence of the O-ring (3) and anti-twist device (4) during reassembly, and verify protective conductor continuity between coil ground and valve body.

Maintenance, Troubleshooting & Spare Parts

In continuous operation, functional reliability is maintained by periodic cycling. For systems subject to extended downtime, executing at least 1 to 2 switching operations daily is recommended.

Troubleshooting Guide

Symptom	Probable Cause	Corrective Action
Valve does not actuate	Electrical interruption or coil short circuit	Check power supply, voltage, and coil resistance
Valve does not actuate	Core area contaminated or seized	Clean core guide tube, plunger, and armature area
Valve does not actuate	Operating pressure out of bounds	Verify supply pressure is within 0.2 to 16 bar range
Valve does not close	Valve interior or pilot channel blocked	Clean body interior; clear pilot bore in diaphragm
Valve does not close	Diaphragm defective or degraded	Replace diaphragm and seal assembly

Spare Part Sets

Original factory spare parts are ordered by referencing device article number 20093842 and the required set code:

• SET 1: Solenoid assembly and core guide kit
• SET 3: Core plunger, return spring, and pilot seal kit
• SET 7: Diaphragm, diaphragm support, and body O-ring set

Compatible Accessories & Related Models

Electrical cable plugs must be ordered separately. Compatible Type 2518 and Type 2509 connectors complying with DIN EN 175301-803 Form A include:

Accessory Description	Operating Voltage	Article No.
Type 2518 Cable Plug without wiring	0–250 V AC/DC	314802
Type 2518 Cable Plug with LED indicator	12–24 V AC/DC	314812
Type 2518 Cable Plug with LED and varistor	12–24 V AC/DC	314820
Type 2518 Cable Plug with rectifier, LED, and varistor	12–24 V AC/DC	314816
Type 2509 Cable Plug standard without wiring	0–250 V AC/DC	137943

Related G 3/4 (DN 20) Brass Body Variants

Article No.	Circuit Function	Seal Material	Voltage / Frequency	Pressure Range	Kv (Water)
20093842	A (NC)	EPDM	24 V AC (50/60 Hz)	0.2–16 bar	8.5 m³/h
221905	A (NC)	EPDM	24 V AC (50/60 Hz)	0.2–16 bar	8.5 m³/h
221904	A (NC)	EPDM	24 V DC	0.2–16 bar	8.5 m³/h
221906	A (NC)	EPDM	230 V AC (50/60 Hz)	0.2–16 bar	8.5 m³/h
221851	A (NC)	NBR	24 V AC (50/60 Hz)	0.2–16 bar	8.5 m³/h
221850	A (NC)	NBR	24 V DC	0.2–16 bar	8.5 m³/h
221852	A (NC)	NBR	230 V AC (50/60 Hz)	0.2–16 bar	8.5 m³/h