BURKERT 320460 (Type 3280) is an electromotive direct-acting 2-way globe control valve designed for dosing neutral liquids and gases in continuous control applications. The valve is driven by an internal linear stepper motor and integrates dedicated control electronics, eliminating the need for external actuation modules. To maintain a set opening position, the stepper motor consumes less than 1 W of holding power, reducing total plant electrical demand. Article 320460 is built with a brass body, G 1/4 internal thread, 1 mm seat orifice (Kv 0.03 m³/h), PEEK/EPDM seat seal, and an integrated process controller featuring a digital CANopen (büS) interface and a 4-20 mA sensor input.

Fluid flows below the seat against the closing direction, preventing water hammer and enabling stable continuous modulation with a closing time of 2.5 seconds and a position control dead band of ±0.5% (corresponding to a 1:100 setting range).

Technical Data

Parameter	Specification
Valve Design	Direct-acting electromotive 2-way globe control valve
Article Number (SKU)	320460
Basic Type	3280
Nominal Seat Size	DN 1 (1 mm / 1/32")
Port Connection	G 1/4 internal thread (EN ISO 228-1)
Flow Coefficient (Kv)	0.03 m³/h (water at +20 °C, Δp = 1 bar)
Operating Pressure Range	0 to 6 bar(g)
Valve Seat Seal	PEEK / EPDM
Body Material	Brass
Actuator Housing	PC (cover) / PPS (base)
Fluid Temperature Range	0 °C to +70 °C
Ambient Temperature Range	-10 °C to +60 °C (subject to duty cycle derating)
Operating Voltage	24 V DC ± 10% (max. residual ripple 10%)
Power Consumption	< 1 W holding position; max. 8 W operating (DN 1 to DN 6)
Fluid Viscosity Limit	Max. 600 mm²/s (cSt)
Flow Direction	Below seat (against closing direction)
Closing Time	2.5 s
Enclosure Rating	IP54 (with properly attached mating connectors)
Mounting Position	Any position, preferably with actuator upright
Total Unit Weight	Approx. 0.7 kg

Approvals and Conformities

BURKERT Type 3280 complies with relevant EU Directives as detailed in the EU Declaration of Conformity.

• North America: Optional UL Recognized certification for the USA and Canada in accordance with UL 429 (electrically operated valves) and CAN/CSA-C22.2 No. 139. Operation requires an external NEC Class 2 power supply or NEC Class 2 transformer compliant with UL 1310 or UL 1585.
• Food and Beverage / Hygiene: All media-wetted components comply with the Code of Federal Regulations published by the United States Food and Drug Administration (FDA).
• Oxygen Applications: Optional product configurations are available for gaseous oxygen service.

Materials of Construction

Item No.	Component	Material
1	Housing cover	Polycarbonate (PC)
2	Housing base	Polyphenylene sulphide (PPS)
3	Spindle seal	EPDM / FKM / NBR
4	Spindle	Stainless steel 1.4305
5	Upper valve body	Brass or stainless steel 1.4305
6	Guided piston with parabolic plug	PTFE / Stainless steel 1.4305
7	Elastomer seat seal	PEEK / EPDM (PEEK used for seat sizes 1 and 1.5 mm)
8	O-ring	EPDM / FKM / NBR
9	Valve seat	Stainless steel 1.4301 / 1.4305
10	Valve body	Brass (AISI 316L stainless steel optional)

Seat Seal Note

For seat sizes 1 mm and 1.5 mm, PEEK seat seals are used in combination with elastomer sealing elements. Seat tightness is reduced in these ultra-small orifice executions compared to soft elastomer seals.

Dimensions and Installation

Threaded Body Dimensions (mm)

Port Thread (D)	A	B	C	E	F	G	H
G 1/4 (320460)	—	—	12	96.4	134.2	10	27.5
NPT 1/4	5.8	10.0	—	96.4	134.2	10	27.5
G 3/8	—	—	12	97.4	137.2	12	27.5
NPT 3/8	6.0	10.3	—	97.4	137.2	12	27.5
G 1/2	—	—	14	97.4	139.2	14	29.5
NPT 1/2	8.2	13.7	—	97.4	139.2	14	29.5

Alternative Connection Forms

Type 3280 is also manufactured in sub-base (flange) configurations and cartridge configurations for direct block integration. Dimensions and cavity drawings are documented in the Type 3280 operating instructions.

Electrical Connections and Pin Assignment

BURKERT 320460 operates as a digital process controller execution. It features two M12 circular connectors: a 5-pin A-coded plug for power and digital communication (büS/CANopen), and a 5-pin A-coded socket for the external process variable input.

Digital Fieldbus Connection (M12 Plug, A-coded, 5-pin)

Pin	Configuration	Function
1	Shield	Bus cable shielding
2	24 V DC	Main operating power supply
3	GND	Power supply ground
4	CAN_H	CANopen dominant high line
5	CAN_L	CANopen dominant low line

Process Actual Value Sensor Input (M12 Socket, A-coded, 5-pin)

Pin	Configuration	Function
1	24 V DC	Sensor power supply output
2	Analogue IN	Process sensor signal: 4-20 mA (input impedance 60 Ω), 0-20 mA, 0-5/10 V (22 kΩ), or frequency (5-2000 Hz)
3	GND	Sensor ground
4	GND	Sensor ground (bridged internally to pin 3)
5	Not connected	Unassigned

Standard Analogue Pinout Reference (8-pin M12)

Standard on/off and positioner variants use an 8-pin A-coded M12 connector: Pin 1 (24 V DC), Pin 2 (Power GND), Pins 3/4/5 (Internal büS use for configuration via büS stick), Pin 6 (Signal input +), Pin 7 (Signal output actual value), Pin 8 (Signal GND).

Performance Specifications and Sizing

Duty Cycle and Ambient Temperature Derating

Duty Cycle Limits

In electromotive valves, duty cycle represents the active run time of the stepper motor, not the electrical power-on duration of the device. Motor self-heating limits continuous positioning movements. Frequent setpoint oscillations increase motor duty cycle and can reduce service life. Operating outside the permissible derating boundary risks thermal motor degradation.

Standard Variant Pressure Range and Flow Capacity

Valve Function	Seat Size (DN)	Port Connection	Kvs Value [m³/h]	Operating Pressure Range [bar(g)]
Control valve (320460)	1.0	G 1/4	0.030	0 to 6
Control valve	1.5	G 1/4	0.065	0 to 6
Control valve	2.0	G 1/4	0.130	0 to 6
Control valve	3.0	G 1/4	0.300	0 to 6
Control valve	4.0	G 3/8	0.500	0 to 6
Control valve	5.0	G 3/8	0.750	0 to 6
Control valve	6.0	G 3/8	0.900	0 to 6
Control valve	8.0	G 1/2	1.500	0 to 6
Control valve	10.0	G 1/2	1.900	0 to 6

Flow Calculation and Valve Sizing

To ensure stable control performance, the nominal seat diameter must be sized so that at maximum flow, a substantial fraction of the total system pressure loss occurs across the valve:

$$\Delta p_{\text{valve}} > 25% \text{ of total system pressure drop}$$

If the valve pressure drop is too small relative to piping resistance, the inherent linear valve characteristic will deform into an uneven, distorted system curve.

• Sub-critical liquid flow: $$K_v = Q \cdot \sqrt{\frac{\rho}{1000 \cdot \Delta p}}$$
• Sub-critical gas flow ($p_2 > p_1 / 2$): $$K_v = \frac{Q_N}{514} \cdot \sqrt{\frac{T_1 \cdot \rho_N}{p_2 \cdot \Delta p}}$$
• Supercritical gas flow ($p_2 < p_1 / 2$): $$K_v = \frac{Q_N}{257 \cdot p_1} \cdot \sqrt{T_1 \cdot \rho_N}$$

Process Controller Operation

In the process controller configuration (device variant D), an integrated PID algorithm performs cascade control without requiring a supervisory PLC loop:

1. Outer Process Loop: The external sensor actual value (PV) received via the 5-pin M12 socket (e.g., 4-20 mA from a flowmeter or pressure transmitter) is compared with the internal process setpoint (SP). The PID controller calculates the valve position setpoint (CMD).
2. Subordinate Position Loop: An internal non-contact displacement sensor measures the real-time linear spindle position (POS). The subordinate position controller evaluates control difference Xd2 between CMD and POS, generating motor command signals (CTRL) to adjust stroke and eliminate disturbances Z2.
3. Status Reporting: Two integrated LEDs signal travel status and limit reach. Operating values and diagnostic data are transmitted digitally over the CANopen/büS fieldbus.

Accessories and System Integration

Capacitive Buffer Module

For applications requiring a defined fail-safe position during complete power failure, Type 3280 can be powered through the external capacitive buffer module (Type 1573, Ident 773440). Upon supply failure, the module delivers 18 V DC backup power for several seconds, enabling the actuator to travel to its pre-configured safety position (factory setting: fully closed). Up to three Type 3280 valves can connect to one module.

Ordering Chart Accessories

Item Description	Article No.
Power supply unit Phoenix Class 2 (Type 1573), 85-240 V AC / 24 V DC, 1.25 A, NEC Class 2 (UL 1310)	772438
DIN rail power supply unit (Type 1573), 100-240 V AC / 24 V DC, 1.0 A, NEC Class 2 (UL 1310)	772361
DIN rail power supply unit (Type 1573), 100-240 V AC / 24 V DC, 2.0 A, NEC Class 2 (UL 1310)	772362
DIN rail power supply unit (Type 1573), 100-240 V AC / 24 V DC, 3.8 A, NEC Class 2 (UL 60950-1)	772898
Capacitive buffer module (Type 1573) for power-loss fail-safe return	773440
M12 shielded cable, 5-pin, length 2.0 m, pre-assembled for process sensor input	559177
M12 circular socket with cable, 8-pin, length 2.0 m, unshielded	919061
M12 circular socket with cable, 8-pin, length 2.0 m, shielded	918991
büS adapter, M12 socket 8-pin to M12 plug 5-pin (for büS stick connection)	773286
USB-büS interface set 1 (Type 8923) with büS stick, terminating resistor, power supply, and software	772426
USB-büS interface set 2 (Type 8923) with büS stick, M12 and micro-USB cables, Y-distributor, 0.7 m	772551
Bürkert Communicator configuration software	Type 8920