BURKERT Type 3280 (item 329186) is a direct-acting electromotive 2-way globe control valve designed for dosing neutral liquid and gaseous media in closed or open control loops. Driven by a linear stepper motor coupled to a threaded spindle, the valve delivers continuous throttling with a closing time of approximately 2.5 seconds. Integrated control electronics handle position regulation directly from an external analogue signal without requiring external driver modules. In stationary holding positions, the motor is switched off, reducing continuous electrical power consumption to below 1 W.

This specific configuration incorporates a brass valve body with internal NPT 3/8" threaded ports, a 6 mm seat orifice (DN 6), and an EPDM elastomer seat and stem seal. Operating within a fluid pressure range of 0 to 6 bar(g), it achieves a nominal flow coefficient Kv of 0.9 m³/h with flow directed underneath the valve seat.

Technical Specifications

Specification Parameter	Value / Range
Valve Type / Article Number	Type 3280 / 329186
Control Function	Standard control valve (Version H, continuous positioning)
Port Connection	NPT 3/8" female thread (ASME B1.20.1)
Seat Orifice Diameter	6 mm (1/4")
Flow Rate Kv Value (Water)	0.9 m³/h
Operating Pressure Range	0 to 6 bar(g)
Supply Voltage	24 V DC ±10% (max. residual ripple 10%)
Power Consumption	< 1 W holding mode; max. 8 W operating (DN 2 to DN 6)
Actuating Time (0 to 100%)	Approx. 2.5 s (normal speed) / 5 s (slow speed)
Analogue Set-Point Input	0 to 10 V (default, 22 kΩ input impedance); selectable 4 to 20 mA (60 Ω)
Digital Output Feedback	PNP, max. 100 mA current limit (active when valve closed)
Dead Band of Position Control	±0.5% (relative to full stroke range, setting range 1:100)
Medium Temperature	0 °C to +70 °C (EPDM material limits: -30 °C to +70 °C)
Ambient Temperature	-10 °C to +60 °C (subject to motor duty cycle derating)
Flow Direction	Under seat (flow against closing direction)
Maximum Viscosity	600 mm²/s (cSt)
Enclosure Rating	IP54 (with mated M12 connection cable)
Weight	Approx. 0.7 kg

Materials and Mechanical Construction

The Type 3280 actuator is completely isolated from the process fluid. Translational movement generated by the stepper motor threaded spindle drives the rigid valve spindle connected to a parabolic control element. The guiding shaft and piston maintain precise alignment during repeated cycling.

Item	Component	Material
1	Housing Cover	Polycarbonate (PC GF10)
2	Housing Base	Polyphenylene sulfide (PPS GF40)
3	Spindle Seal	EPDM (Ethylene-propylene-diene rubber)
4	Spindle	Stainless steel 1.4305
5	Upper Valve Body	Brass
6	Piston with Parabolic Control Element	PTFE and Stainless steel 1.4305
7	Elastomer Seat Seal	EPDM
8	O-Ring	EPDM
9	Seat Ring	Stainless steel 1.4301 / 1.4305
10	Valve Body	Brass

INFO

All wetted materials in contact with the operating fluid conform to the Code of Federal Regulations published by the FDA according to the manufacturer declaration.

Dimensions

Dimensions for threaded body variants of Type 3280 (all dimensions in mm):

Port Thread D	A	B	C	E	F	G	H
NPT 3/8" (329186)	6.0	10.3	—	97.4	137.2	12.0	27.5
G 3/8"	—	—	12.0	97.4	137.2	12.0	27.5
NPT 1/4"	5.8	10.0	—	96.4	134.2	10.0	27.5
G 1/4"	—	—	12.0	96.4	134.2	10.0	27.5
NPT 1/2"	8.2	13.7	—	97.4	139.2	14.0	29.5
G 1/2"	—	—	14.0	97.4	139.2	14.0	29.5

Actuator housing mounting threads: 4× M4 female threads, depth 4.5 mm, spaced at pitch centres of 27.5 mm.

Electrical Installation and Pin Assignment

Electrical connection is established via an 8-pin M12 A-coded circular connector located on the side of the actuator. None of the electrical inputs and outputs are galvanically isolated from the 24 V DC supply voltage. The threaded metal sleeve of the M12 connector connects directly to the valve body for protective earth bonding.

Pin	Wire Colour (Cable 919061)	Configuration	Function / Operating Signal
1	White	Supply +	24 V DC ±10%, max. residual ripple 10%
2	Brown	Supply GND	24 V DC ground
3	Green	Do not connect	Electrically insulate wire on connection line
4	Yellow	Do not connect	Electrically insulate wire on connection line
5	Grey	Do not connect	Electrically insulate wire on connection line
6	Pink	Set-point value input +	0 to 10 V (default) / 4 to 20 mA or PWM (800 Hz)
7	Blue	Digital output	PNP, max. 100 mA (0 to 5 V = log 0; 10 to 30 V = log 1 closed)
8	Red	Signal GND	Signal reference ground
Body	—	Shielding	Connected to valve body / functional ground

WARNING

Do not connect pins 3, 4, or 5 on standard control valve devices. The cable shield must be grounded via the M12 connector housing to comply with electromagnetic compatibility (EMC) requirements.

Functional Logic and Control Configuration

The standard control valve version converts the external analogue set-point value directly into a valve position. Status indication is handled visually through the multi-colour LED on the actuator cover. In addition, when the valve reaches its closed end position, the internal digital transistor output (Pin 7) switches to active high (10 to 30 V DC).

• Zero-Point Shut-Off: The valve features an integrated zero-point cut-off threshold. If the incoming analogue set-point value drops below 1% of the input range, the drive automatically moves the valve into a tight shut-off position.
• Power Failure Behaviour: In standard configuration without external buffering, an interruption in the 24 V DC power supply causes the valve to remain stationary in its last position. Upon re-energisation, the internal electronics automatically detect the spindle position and recalibrate to match the active set-point.
• Signal Fault Detection: When configured for a 4 to 20 mA input signal, a drop below 4 mA causes the valve to hold position while the LED flashes red to signal cable breakage.

DIP Switch Settings

Four internal DIP switches located on the electronic PCB beneath the actuator cover permit hardware adaptation of operating parameters:

DIP Switch	Position	Control Valve Function (Version H)
1	OFF	Normal operating direction (increasing signal opens valve, e.g. 0 to 10 V = 0 to 100% stroke)
	ON	Inverted operating direction (decreasing signal opens valve, e.g. 10 to 0 V = 0 to 100% stroke)
2	OFF	Set-point value input: 4 to 20 mA (input impedance 60 Ω)
	ON	Set-point value input: 0 to 10 V (input impedance 22 kΩ, factory setting for 329186)
3	OFF	Actuating speed: Normal mode (approx. 2.5 s for full stroke)
	ON	Actuating speed: Slow mode (approx. 5.0 s for full stroke)
4	OFF	Low power function: Off (full torque and standard operating pressure up to 6 bar)
	ON	Low power function: On (reduced motor current and lower heat emission; max. medium pressure 3 bar, max. Δp 1 bar)

Actuator Cover Removal and Assembly

Disconnect power before opening the 4 captive screws on the bottom side of the actuator housing. When lifting the cover, support the connection plate on the connector plug so it remains seated on the housing. When reassembling, verify that internal wiring is not pinched and tighten screws to 2 Nm.

Performance and Flow Sizing

Duty Cycle Derating

Duty cycle refers to the actual running time of the stepper motor during repositioning. High ambient temperatures increase internal motor heating. For DN 6 valves with fluid pressures up to 6 bar, continuous 100% duty cycle is permitted at ambient temperatures up to +40 °C. At +60 °C ambient, permissible motor duty cycle decreases to approximately 40%. Operating beyond recommended duty cycle limits leads to overheating and reduced operating life.

Linear Flow Characteristics

Model 329186 features a parabolic valve plug delivering a linear flow characteristic with a nominal Kv value of 0.9 m³/h at 100% stroke. To ensure responsive closed-loop control across the operating span, the pressure drop across the fully opened valve should represent at least 25% of the total system pressure drop (Δp_valve > 0.25 · Δp_total).

For fluid calculation:

• Sub-critical liquid flow: $$K_v = Q \cdot \sqrt{\frac{\rho}{1000 \cdot \Delta p}}$$ where $Q$ is volumetric flow in m³/h, $\rho$ is density in kg/m³, and $\Delta p$ is differential pressure in bar.

Emergency Safety Position and Accessories

To drive the valve into a predetermined safe position during a power failure, an external capacitive buffer module (Type 1573, Article no. 773440) can be placed in line with the 24 V DC power feed. In the event of mains power loss, the buffer module supplies 18 V DC for several seconds. The valve electronics detect the voltage drop and automatically drive the spindle to the closed safety position.

Accessory Description	Article Number
Capacitive buffer module (Type 1573) for power failure safety position	773440
M12 circular socket with 2 m cable, 8-pin, unshielded	919061
M12 circular socket with 2 m cable, 8-pin, shielded	918991
Rail-mounted power supply (Type 1573), 100 to 240 V AC / 24 V DC, 1 A, NEC Class 2	772361
Rail-mounted power supply (Type 1573), 100 to 240 V AC / 24 V DC, 2 A, NEC Class 2	772362

Maintenance and Troubleshooting

Under clean process fluid conditions, BURKERT Type 3280 is maintenance-free. Clean external housing parts using neutral agents; do not use alkaline cleaning solutions.

Fault Symptom	Probable Cause	Corrective Action
LED off	24 V DC supply disconnected or polarity inverted	Check power wiring at M12 pins 1 (+) and 2 (-)
LED flashes red	Supply voltage ripple exceeds 10%	Use regulated power supply with smooth output voltage
	Overheating detected	Verify ambient temperature against derating curve; reduce repositioning frequency
	Set-point signal < 4 mA (when 4-20 mA selected)	Check analogue control loop wiring for breaks
Valve does not open	Set-point value below 1% cut-off threshold	Increase set-point signal above cut-off limit
Valve reverses action	DIP switch 1 set incorrectly	Invert DIP switch 1 setting
Incomplete travel	Low power mode enabled on excessive differential pressure	Switch DIP switch 4 to OFF
Internal seat leakage	Debris trapped between seat and seal	Flush piping; inspect seat; install upstream dirt filter (≤ 0.3 mm)