BURKERT Type 6281 is a servo-assisted 2/2-way diaphragm solenoid valve designed for controlling, shutting off, and dosing neutral media. A minimum differential pressure is always required for the valve to function. Various diaphragm materials and circuit functions are available depending on the actual application. The standard brass body meets European drinking water requirements, with dezincification-resistant brass and stainless steel body variants also available for other markets. To reduce electrical power consumption during operation, coils with integrated Kick-and-Drop (KD) electronics featuring double coil technology are available. The valve can be supplied with a manual override for easy maintenance and commissioning.

General Technical Data

Product properties
Seal	NBR, EPDM, FKM
Body	Brass acc. to DIN EN 50930 - 6, stainless steel (dezincification resistant on request)
Inner valve parts	Stainless steel, brass, plastic (PPS)
Orifice	DN 10...DN 50
Thermal insulation class	Polyamide coil class B, Epoxy coil class H
Duty cycle	100 % continuous operation
Switching time	Opening: 0.1...1.5 s, Closing: 0.2...4 s
Operating voltage	24 V DC, 24 V UC, 24 V 50/60 Hz, 230 V UC, 230 V 50/60 Hz
Voltage tolerance	±10 %
Degree of protection	IP65 in accordance with DIN EN 60529/IEC 60529 with cable plug

INFO

Switching time measurement at +20 °C, 6 bar at the valve inlet and free outlet. Opening: pressure reduction to 90 % of the difference to the flow pressure. Closing: pressure build-up to 90 % of the inlet pressure.

Circuit Functions

Symbol	Description
Circuit function A (CF A)	2/2-way solenoid valve, Servo-controlled, Normally closed
Circuit function B (CF B)	2/2-way solenoid valve, Servo-controlled, Normally open

Approvals and Conformities

• Explosion Protection: Optional ATEX/IECEx approvals available (e.g., II 2G Ex mb IIC T4 Gb, II 2D Ex mb IIIC T130 °C Db).
• North America (USA/Canada): UL Listed for Hazardous Locations, UL Recognized, and CSA approved variants available.
• Drinking Water: Suitable for use in drinking water applications. Materials comply with the assessment principles (UBA) for materials in contact with drinking water (TrinkwasserV).
• DNV GL Classification: Accepted for installation on all vessels classed by DNV GL.
• Oxygen: Optional suitability for gaseous oxygen.

Materials

No.	Element	Material
1	Coil	Polyamide or epoxy
2	Stopper	Stainless steel 1.4113
3	Shading ring	Cu (brass variant), Ag (stainless steel variant)
4	Magnetic core	Stainless steel 1.4113
5	O-ring	NBR, FKM, EPDM
6	Core seal	NBR, FKM, EPDM
7	Spring	Stainless steel 1.4310
8	O-ring	NBR, FKM, EPDM
9	Diaphragm	NBR, FKM, EPDM
10	Diaphragm holder	PPSGF40, DN 50: brass and stainless steel
11	Valve body	Brass acc. to DIN EN 50930 - 6 or stainless steel 1.4408 (CF8M)

Dimensions

Standard Threaded Variant

View Coil Dimensions

Coil size	H	J	K	M	O
5	32	20.5	45	41	3.4
6	40	23.5	51	41.4	3.8

Standard Flange Variant (DIN EN 1092-1)

DN	A	B	C	D	L	N	P	R	S	T
25	102.6	160.1	70	85	160	15	68	115	14	85
40	116.2	186.6	99	114	180	23	78	140	18	100
50	119.9	202.4	115	132	230	37	102	165	18	125

Installation and Operation

DANGER!

Risk of injury from high pressure in the system Before loosening lines or valves, switch off the pressure and vent the lines.

Risk of injury from electric shock Before reaching into the device or the system, switch off the power supply and secure it against reactivation. Observe the applicable accident prevention and safety regulations for electrical devices.

WARNING!

Risk of injury due to improper installation Installation must be carried out by authorised technicians only and with the appropriate tools. Secure the system against unintentional activation and ensure a controlled restart after installation.

Installation Approach

1. Clean pipelines of any contamination.
2. Install a dirt trap upstream of the valve inlet (≤ 500 µm).
3. Hold the device on the body using an open-end wrench and screw into the pipeline. Do not use the solenoid as a lever arm.
4. Observe the flow direction: the arrow on the body indicates the flow direction.

Manual Override (Optional)

To manually operate the valve, the hand lever must be turned to a vertical position below the solenoid.

WARNING

Do not over-rotate the hand lever. When the hand lever is actuated, the valve can no longer be switched electrically.