Burkert Type 6281 is a servo-assisted diaphragm valve designed for controlling, shutting off, and dosing neutral media with a viscosity of up to 21 mm²/s. A minimum differential pressure is always required for the valve to function. The standard brass body meets European drinking water requirements, while dezincification-resistant brass and stainless steel variants are available for other applications. To reduce electrical power consumption during operation, coils with integrated Kick and Drop (KD) electronics featuring double coil technology are available.

General Technical Data

Property	Specification
Orifice	DN 10 to DN 50
Body Material	Brass acc. to DIN EN 50930-6, Stainless steel (dezincification resistant on request)
Seal Material	NBR, EPDM, FKM
Inner Valve Parts	Stainless steel, brass, plastic (PPS)
Duty Cycle	100% continuous operation
Switching Time	Opening: 0.1 to 1.5 s / Closing: 0.2 to 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 with cable plug, cable connection, and terminal box

Medium Temperature Limits

• With NBR: -10 °C to +80 °C
• With EPDM: -30 °C to +90 °C (with epoxy coil to +100 °C); 0 °C to +60 °C (with drinking water approval according to UBA PF36)
• With FKM: 0 °C to +90 °C (with epoxy coil to +120 °C)

Material Specifications

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)

Approvals and Conformities

• Explosion Protection: ATEX (II 2G Ex mb IIC T4 Gb, II 2D Ex mb IIIC T130 °C Db) and IECEx variants available.
• North America: UL Recognized for the USA (UL 429, UL 429A) and CSA approved for Canada (CSA 139).
• Drinking Water: Suitable for use in drinking water applications. Materials comply with UBA assessment principles (PF39 for hot water up to +85 °C, PF36 for warm water up to +60 °C).
• DNV GL Classification: Accepted for installation on all vessels classed by DNV GL.
• Oxygen: Optional suitability for gaseous oxygen.

Type Label

The type label includes: 1. Type, 2. Circuit function, 3. Orifice, 4. Sealing material, 5. Body material, 6. PN, 7. Connection type, 8. Power, 9. Frequency, 10. Voltage, 11. Manufacture code, 12. Article number.

Installation and Operation

Safety Instructions

• High Pressure: Before loosening lines and valves, turn off the pressure and vent the lines.
• Electrical Voltage: Before reaching into the device or the system, switch off the power supply and secure it against reactivation.
• Hot Surface: Keep the device away from highly flammable substances and do not touch with bare hands during continuous operation.

Manual Override (Optional)

To manually operate the valve (optional for Type 6281, code HA15/HA17), the hand lever must be turned to a vertical position below the solenoid. Do not over-rotate the hand lever. When the hand lever is actuated, the valve can no longer be switched electrically.