BURKERT 20093966 (Type 3361) is an electromotive 2-way globe control valve engineered for demanding continuous control tasks in process automation. Driven by a brushless DC motor with an integrated ball screw linear actuator, the unit achieves a positioning linear speed of 6 mm/s with a position deadband of ±0.1%. This configuration features port size DN 25 with welded pipe ends according to DIN EN ISO 1127 / ISO 4200 / DIN 11866 Series B, a hardened stainless steel seat and cone set (orifice size 25 mm) delivering a rated Kvs value of 12 m³/h, an equal percentage 50:1 flow characteristic, and an operating pressure range of 0 to 25 bar(g).

Article 20093966 is delivered in a normally closed fail-safe configuration powered by the integrated SAFEPOS energy-pack. It operates on a 24 V DC power supply, includes an integrated positioner with an illuminated display module, provides multi-signal analog and digital input/output connections, and has undergone specific testing for oxygen service compatibility up to 25 bar(g) at temperatures between -10 °C and +60 °C.

Technical Specifications

Parameter	Specification Details
Article Number (MPN)	20093966
Type	3361
Valve Construction	2-way globe control valve (flow below seat, 2 → 1)
Pipe Connection	Welded spigot: DIN EN ISO 1127 / ISO 4200 / DIN 11866 Series B
Port Connection Size	DN 25 (NPS 1), tube dimensions 33.7 x 2.0 mm
Valve Seat Diameter	25 mm (Seat size 25)
Nominal Pressure Class	PN 25 (DIN EN 1333), Class 150 (DIN EN 1759)
Operating Pressure Range	0 to 25 bar(g)
Rated Flow Coefficient	Kvs 12 m³/h (Cv 14 gpm)
Theoretical Control Ratio	50:1 (equal percentage curve)
Seat Leakage Class	Class IV according to DIN EN 60534-4 (metal-to-metal hardened seat)
Actuator Size & Thrust	AG2 (1,300 N driving force)
Positioning Speed	6 mm/s
Control Deadband	±0.1%
Closing Time	3.3 to 6.6 s (typical 3.3 s depending on operating conditions)
Supply Voltage	24 V DC ±10% (maximum residual ripple 10%)
Current Consumption	Max. 3 A (at max. load, including 1 A charging current for SAFEPOS energy-pack)
Standby Power	2 to 5 W
Medium Temperature Range	-10 °C to +60 °C (oxygen version rating)
Ambient Temperature Range	-25 °C to +55 °C
Fluid Viscosity Limit	Up to 600 mm²/s
Ingress Protection Rating	IP65 / IP67 (DIN EN 60529), NEMA 4X
Protection Class	Class III (DIN EN 61140)
Duty Cycle	100% continuous

Materials of Construction

The wetted section and electromotive drive housing use corrosion-resistant materials suitable for clean industrial processes and aggressive environmental conditions.

Actuator Materials (AG2 Execution)

Item	Component	Material
1	Display housing / blind cover	PPS (polyphenylene sulphide)
2	Actuator cover	PPS
3	Actuator cover seals	EPDM
4	Actuator housing	Powder-coated aluminium
6	Housing seal	EPDM
7	Actuator base	PPS

Valve Body and Internal Trim Materials

Item	Component	Material Specification
1	Valve spindle	Stainless steel 1.4401 (316) / 1.4404 (316L)
2	Spindle sealing gland	Self-adjusting solid PTFE V-rings with spring compensation
3	Spindle guide	Stainless steel 1.4404 (316L)
4	Packing gland tube	Stainless steel 1.4401 (316)
5	Body seal ring	Graphite or PTFE
6	Seat seal	Hardened stainless steel 1.4571 (metallic seal)
7	Control cone	Hardened stainless steel 1.4571
8	Screw-in valve seat	Hardened stainless steel 1.4571
9	Seat O-ring	EPDM or PTFE
10	Valve body	Cast stainless steel CF3M

Dimensional Specifications

Type 3361 DN 25 with welded spigots complies with standardized tube line dimensions. Actuator height H1 indicates standard configuration without fieldbus gateway module.

Welded End Dimensions (DIN EN ISO 1127 / ISO 4200 / DIN 11866 Series B)

Nominal Port DN	Pipe OD ∅ DS [mm]	Wall Thickness WS [mm]	Port Length LS [mm]	Spigot Length ES [mm]	Standard Height H1 [mm]
DN 10	17.2	1.6	90	20	417
DN 15	21.3	1.6	90	20	417
DN 20	26.9	1.6	100	20	423
DN 25	33.7	2.0	130	26	446
DN 32	42.4	2.0	140	26	474
DN 40	48.3	2.0	150	26	479
DN 50	60.3	2.0	175	26	485

Actuator Dimensions in Closed State

In the fully seated closed position without tight-closing function enabled, the actuator height extends upward by approximately 2 mm.

Flow Characteristics and Seat Performance

The equal percentage flow characteristic curve conforms to DIN EN 60534-2-4 with a theoretical control ratio of 50:1. Medium flow must be directed below the seat (from port 2 to port 1).

Flow Values Across Valve Stroke for DN 25 Seat Size 25

Stroke [%]	Kv Value [m³/h]	Stroke [%]	Kv Value [m³/h]
5%	0.35	60%	3.4
10%	0.38	70%	5.1
20%	0.65	80%	7.0
30%	1.0	90%	9.4
40%	1.5	100% (Kvs)	12.0
50%	2.2	Theoretical Control Ratio	50:1

Hardened stainless steel trims (seat and cone) resist mechanical erosion, cavitation, and abrasive media, providing extended service intervals under rigorous process conditions. Seat leakage conforms to DIN EN 60534-4 Class IV (permissible leakage rate 0.01% of nominal flow capacity).

Electrical Control and Connections

Electrical connections are routed via industrial M12 circular connectors. The valve operates with standard analog setpoints while supplying active process status feedback.

Control Signal Specifications

• Analog Setpoint Input: Electrically isolated from operating voltage and analog output; configurable for 0/4 to 20 mA (input impedance 70 Ω) or 0 to 5/10 V (input impedance 22 kΩ).
• Analog Output: Active feedback signal; max. 10 mA (voltage mode 0 to 5/10 V) or load 0 to 800 Ω (current mode 0/4 to 20 mA).
• Digital Input: 0 to 5 V = logical "0", 10 to 30 V = logical "1".
• Digital Outputs: 2 PNP outputs, current limited to 100 mA each.
• büS Service Interface: Communicates via USB büS interface set to the Bürkert Communicator PC software for detailed configuration and diagnostic logs.

Circular Connector Pin Assignments (AG2)

X1 Connector: M12 Circular Plug, 8-Pin, A-Coded (Input and Output Signals)

Pin	Signal Assignment
1	Digital input +
2	GND for digital input and digital outputs
3	Digital output 2 +
4	Digital output 1 +
5	Analogue output -
6	Analogue output +
7	Setpoint / analogue input -
8	Setpoint / analogue input +

X3 Connector: M12 Circular Plug, 5-Pin, A-Coded (Operating Voltage & büS)

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

Device Architecture and Operation

Type 3361 AG2 features a hygienic, enclosed aluminium and high-performance polymer housing with IP65/IP67 rating and vibration resistance.

Mechanical and Structural Elements

1. Display Module & 360° LED Ring: Displays device status, operating modes, and valve positions using customizable color coding.
2. Actuator Cover and Housing: Encloses the brushless motor, planetary gearing, and ball screw drive mechanism.
3. Mechanical Position Indicator: Visual marker behind a transparent window indicates actual valve travel mechanically without electrical power.
4. Relief Bore: Leakage inspection channel located on the actuator neck for early detection of gland packing wear.
5. Body Connection: High-strength threaded connection equipped with wrench flats (tightening torque 60 ± 3 Nm for DN 25).

Integrated Position Controller

The internal non-contact displacement sensor monitors actual linear position (POS). The digital positioner compares this value against the external setpoint (CMD). If an error deviation (Xd1) occurs, the controller drives the motor with variable CTRL until the setpoint position is reached with a deadband precision of ±0.1%.

Fail-Safe Return Function (SAFEPOS Energy-Pack)

Article 20093966 includes an internal SAFEPOS energy-pack storage module. In the event of an external 24 V DC power failure, the energy pack delivers stored power to move the valve to its programmed safety position (factory preset to fully closed). Charging time to full readiness is 120 seconds or less after power restoration.

Operating Limits & Medium Compatibility

• Non-metallic materials in this oxygen-ready execution are certified for work with gaseous oxygen up to 25 bar(g) and fluid temperatures up to +60 °C.
• Avoid using unapproved greases or lubricants in oxygen service; only use certified media-compatible lubricants (such as Klüberpaste UH1 96-402).
• Always depressurize and drain pipelines before removing the actuator from the valve body.

Maintenance and Assembly Torques

Routine maintenance of the control valve is supported by modular replacement assemblies, including screw-in valve seats and replaceable packing glands.

Component Tightening Torques for DN 25

Connection Point	Tool / Method	Specified Torque
Valve Body Connection	Open-end wrench on flats	60 ± 3 Nm
Valve Seat (Seat size 25)	Installation tool (Order No. 652606)	40 + 5 Nm
Spindle Guide (Packing gland)	Modified socket wrench SW21 (Order No. 683223)	25 Nm
Actuator Housing Fastening Screws	Torx T25	5 Nm
Display / Gateway Fastening Screws	Torx T20 / 3 mm Hex key	1.1 Nm
Mechanical Manual Override	3 mm Allen key	Max. 2 Nm

Control Cone Pinning

When replacing the control cone, the dowel pin on the 14 mm diameter spindle (DN 25 to 50) must be removed and driven in using a 5 mm pin punch while supporting the cylindrical section in a prism fixture. Do not scratch or indent the profiled control surface.

Position Controller Calibration (X.TUNE)

After remounting the actuator or replacing internal trim components, the X.TUNE self-calibration routine must be executed to recalibrate mechanical stroke limits:

1. Ensure that the valve is completely free of medium pressure.
2. On devices with a display module, navigate to CONFIGURATION → Position controller → MAINTENANCE → CALIBRATION → X.TUNE.
3. Alternatively, on devices without a display, hold the internal OPEN and CLOSE buttons down simultaneously for 5 seconds under the dummy cover until the LED ring illuminates orange.