BURKERT 346328 (Type 3361) is an electromotive 2-way globe control valve engineered for demanding continuous control tasks in hygienic and industrial fluid processes. The unit integrates a brushless DC electric linear drive with a ball screw mechanism to position a stainless steel control cone with high repeatability. Operating at a linear speed of 6 mm/s with an AG2 actuator nominal force of 1300 N, the valve reacts to dynamic control setpoints with minimal dead time and maintains an operating dead band of ±0.1%. Fluid pressure variations or system pressure shocks do not transfer to the drive or disrupt spindle position.

This specific configuration incorporates a DN 25 (NPS 1) cast stainless steel CF3M valve body equipped with ASME BPE clamp connections (pipe dimensions 25.4 x 1.65 mm, clamp flange diameter 50.5 mm). Flow enters below the seat (flow direction 2 to 1). Sealing at the seat is executed via a replaceable PTFE soft seal, delivering bubble-tight Class VI shut-off across an operating pressure span from 0 to 25 bar(g). The internal orifice features a 20 mm seat diameter, providing a rated Kv value of 7.1 m³/h (Cv 8.3 gpm) and an equal percentage 50:1 theoretical rangeability. The valve includes an integrated EtherNet/IP industrial Ethernet gateway and a rugged local display interface with operational keys.

INFO

BURKERT 346328 is configured with the standard control function: static position blocking without electrical energy storage. Upon interruption of the 24 V DC electrical power supply, the actuator holds its current physical stroke position.

Technical Specifications

Parameter	Specification
Article Number	346328
Valve Type	3361
Design	Electromotive 2-way globe control valve
Nominal Diameter	DN 25 (NPS 1)
Port Connection	Clamp ASME BPE / BS4825-3 (Tube: 25.4 x 1.65 mm, Cl: 50.5 mm)
Actuator Size / Nominal Force	AG2 (1300 N)
Operating Voltage	24 V DC ±10% (max. residual ripple 10%)
Operating Current	Max. 3 A (load dependent)
Standby Power Consumption	2 to 5 W
Operating Pressure Range	0 to 25 bar(g)
Nominal Pressure Class	PN 25 (DIN EN 1333) / Class 150 (DIN EN 1759)
Medium Temperature Range	-10 °C to +130 °C
Permissible Ambient Temperature	-25 °C to +65 °C (subject to temperature derating)
Seat Orifice Size	20 mm (3/4")
Flow Coefficient	Kv = 7.1 m³/h (Cv = 8.3 gpm)
Flow Characteristic	Equal percentage (theoretical rangeability 50:1)
Seat Leakage Class	Class VI (DIN EN 60534-4)
Actuator Travel Speed	6 mm/s
Typical Closing Time	3.3 s
Dead Band	±0.1%
Flow Direction	Against closing direction (flow below seat, 2 → 1)
Safety Setting on Power Loss	Blocked in last static position
Actuator Weight	Max. 5.5 kg (AG2 actuator)
Ingress Protection Rating	IP65 / IP67 (DIN EN 60529), NEMA 4X
Protection Class	Class III (DIN EN 61140)
Conformity & Approvals	EC Regulation 1935/2004 (food contact materials)

Materials of Construction

Item	Component	Material
1	Display housing / Gateway housing	PPS (standard)
2	Actuator cover	PPS
3, 6	O-ring seals	EPDM
4	Actuator housing	Powder-coated aluminium
7	Actuator base	PPS
—	Spindle	Stainless steel 1.4401 (316) / 1.4404 (316L)
—	Spindle seal	PTFE V-seals (filled) with spring compensation
—	Spindle guide	Stainless steel 1.4404 (316L)
—	Packing gland tube	Stainless steel 1.4401 (316)
—	Valve body seal	Graphite or PTFE
—	Seat seal	PTFE seal washer (Leakage Class VI)
—	Control cone	Stainless steel 1.4571
—	Valve seat	Stainless steel 1.4571
—	Valve seat O-ring	EPDM or PTFE
—	Valve body	Cast stainless steel CF3M

Dimensions and Installation Geometry

Actuator Dimensions (AG2 Fieldbus Configuration)

For nominal diameter DN 25 (NPS 1), the AG2 actuator equipped with the integrated industrial fieldbus gateway corresponds to the following vertical installation dimensions:

• Standard actuator height without fieldbus gateway (H1): 446 mm
• Fieldbus gateway actuator height (H2): 518 mm
• When the valve is in the fully closed position without active tight-closing force, the actuator is raised by approximately 2 mm.

ASME BPE Clamp Connection Dimensions

Parameter	Value (DN 25 / NPS 1)
Connection Standard	ASME BPE / DIN 32676 Series C (Pipe: ASME BPE / DIN 11866 Series C)
Face-to-Face Body Length (LC)	126 mm
Internal Pipe Diameter (∅ D2 C)	25.4 mm
Clamp Flange Outer Diameter (∅ D1 C)	50.5 mm
Pipe Wall Thickness (SC)	1.65 mm

Electrical Connections and Communication Interfaces

BURKERT 346328 utilizes dedicated external M12 circular plug connectors located on the AG2 actuator base and gateway module.

Connector	Coding	Description
X3	M12 circular plug, 5-pin, A-coded	Operating voltage 24 V DC and büS/CANopen communication
X7 (Port 1 & 2)	M12 circular socket, 4-pin, D-coded	Industrial Ethernet fieldbus connection (integrated 2-port Ethernet switch)

Connector Pin Assignments

Operating Voltage and büS / CANopen (X3 Connector)

Pin	Signal Assignment
1	CAN Shield / Functional shield
2	Operating voltage 24 V DC ±10%
3	GND / CAN_GND
4	CAN_H
5	CAN_L

Fieldbus Gateway EtherNet/IP (X7 Connector)

Pin	Signal Assignment
1	Transmit Data + (TX+)
2	Receive Data + (RX+)
3	Transmit Data - (TX-)
4	Receive Data - (RX-)

Fluidic Performance and Operating Limits

The Type 3361 globe control valve follows an equal-percentage flow characteristic according to DIN EN 60534-2-4. For seat size 20 mm, the theoretical rangeability is 50:1. The measured flow coefficients across intermediate spindle strokes are detailed below.

Flow Data for Flow Below Seat (Water, DIN EN 60534-2-4)

Parameter	Performance Value
Nominal Port Diameter	DN 25 (NPS 1)
Seat Orifice Size	20 mm
Actuator Drive Force	1300 N
Max. Operating Pressure (PTFE Seal)	25 bar(g) (Leakage Class VI)
Theoretical Rangeability	50:1
Kv at 5% Stroke	0.20 m³/h
Kv at 10% Stroke	0.25 m³/h
Kv at 20% Stroke	0.31 m³/h
Kv at 30% Stroke	0.47 m³/h
Kv at 40% Stroke	0.70 m³/h
Kv at 50% Stroke	1.1 m³/h
Kv at 60% Stroke	1.6 m³/h
Kv at 70% Stroke	2.5 m³/h
Kv at 80% Stroke	3.8 m³/h
Kv at 90% Stroke	5.4 m³/h
Rated Flow Coefficient Kvs (100% Stroke)	7.1 m³/h (catalogue rating 7.2 m³/h)

Operating Limits

• Maximum working pressure is restricted by the ASME B16.34 Class 150 and DIN EN 12516-1 PN 25 temperature-pressure rating curves.
• For devices equipped with a fieldbus gateway module and display, ambient temperature must be derated according to the operating chart when medium temperatures exceed +100 °C.
• Wetted materials comply with EC Regulation 1935/2004 for food contact applications.

Design and Operational Features

The electromotive linear actuator incorporates a brushless DC motor, mechanical reduction gearing, and a ball screw spindle that displaces the valve stem. Self-locking mechanical transmission holds the valve closed against full line pressure without drawing continuous motor current.

• Status Indication: A 360° illuminated LED light ring is mounted around the display cover to signal system health, setpoint tracking, and intermediate or end positions.
• Mechanical Position Indicator: A mechanical yellow marker positioned behind a clear window displays the current stem travel position even when control power is disconnected.
• Local User Interface: A rugged digital display module with navigation keys allows commissioning, parameter view changes, and manual stroke positioning.
• Service Communication: A büS service interface allows deep diagnostics, parameter backup, and firmware interaction using the Bürkert Communicator software (Type 8920).

Position Control System

The internal displacement transducer monitors the real-time position (POS) of the electric drive shaft. The internal digital positioner compares the measured stem position with the digital setpoint value (CMD) received via EtherNet/IP or the büS interface. System deviation (Xd1) prompts motor actuation (CTRL) to restore setpoint alignment within the ±0.1% dead band.

Mechanical Manual Override

When electrical supply voltage is disconnected, the valve stroke position can be shifted manually using a mechanical manual override mechanism located beneath the display module.

Manual Override Operating Restrictions

• The mechanical manual override must only be engaged when the unit is completely de-energized.
• Use a 3 mm Allen key to engage the drive spindle.
• The maximum tightening torque must not exceed 2 Nm. Exceeding 2 Nm damages the mechanical drive assembly.

Installation, Assembly, and Maintenance

Lubrication Requirement

Always lubricate external threads on the valve body and replacement valve seat inserts with Klüberpaste UH1 96-402 before reassembly to maintain thread integrity and seal compression.

Actuator Assembly and Body Tightening Torques

When removing or reinstalling the electromotive actuator, the valve must be positioned at least 1/3 open (in MANUAL operating mode) to prevent damage to the PTFE seat seal and contour cone. Secure the valve body in a holding device and tighten the body connection to the exact specification:

Connection / Orifice Size	Tightening Torque
DN 10 / 15	45 ±3 Nm
DN 20	50 ±3 Nm
DN 25 (NPS 1)	60 ±3 Nm
DN 32 / 40	65 ±3 Nm
DN 50	70 ±3 Nm

Valve Seat Replacement

The valve seat can be unscrewed from the body using the dedicated Type 3361 installation tool (Order No. 652606 for DN 25):

• Spindle diameter for DN 25: 14 mm (uses 5 mm pin punch for dowel pin removal).
• Lower spindle guide tightening torque: 25 Nm.
• Coated valve seat tightening torque: 40 Nm (+5 Nm tolerance).
• Fieldbus gateway module fastening screw: 1.1 Nm.

X.TUNE Calibration Restriction

After mounting an actuator or servicing the seat/cone assembly, execute the X.TUNE automatic adjustment function to calibrate stroke limits. Never run X.TUNE under active medium pressure. Performing calibration under pressure leads to incorrect stroke calibration and uncontrolled process behavior.