BURKERT 355954 (Type 3361) is an electromotive 2-way globe control valve designed for highly precise, dynamic closed-loop control under demanding operating conditions. This specific model features a DN 25 flange connection (DIN EN 1092-1), a PTFE seat seal, and an AG2 (1300 N) actuator. It is equipped with an integrated positioner and a SAFEPOS energy-pack, ensuring the valve can reach a safe position in the event of a power failure.

The valve body is constructed from flow-optimized stainless steel, offering a hygienic design with a robust surface that is easy to clean. With an IP65/IP67 and NEMA 4X protection rating, it is highly resistant to weather, impact, and vibration, making it suitable for harsh industrial environments.

General Technical Data

Property	Value
Design	Globe control valve
Nominal diameter	DN 25
Safety setting (power failure)	With SAFEPOS energy-pack: open, closed or freely programmable
Flow direction	Against closing direction (below seat)
Controller variant	Positioner
Operating pressure	0...25 bar(g)
Nominal pressure	PN 25 (DIN EN 1333), Class 150 (DIN EN 1759)
Kvs value	12 m³/h
Flow characteristic	Equal percentage 50:1
Operating voltage	24 V DC ± 10 % (maximum residual ripple 10 %)
Medium temperature	-10 °C to +130 °C
Ambient temperature	-25 °C to +65 °C
Degree of protection	IP65/IP67 (DIN EN 60529), NEMA 4X

Approvals and Conformities

This model features FDA and EC 1935/2004 compliant wetted materials, making it suitable for food and beverage applications.

Materials

Actuator Materials (AG2)

No.	Component	Material
1	Display housing/blind cover	PPS (standard)
2	Actuator cover	PPS
3	Seal	EPDM
4	Actuator housing	Powder-coated aluminium
6	Seal	EPDM
7	Actuator base	PPS

Valve Body Materials

No.	Component	Material
1	Spindle	Stainless steel 1.4401 (316)/1.4404 (316L)
2	Spindle seal	PTFE V-seals (filled) with spring compensation
3	Spindle guide	Stainless steel 1.4404 (316L)
4	Packing gland tube	Stainless steel 1.4401 (316)
5	Seal valve body	Graphite or PTFE
6	Seat seal	PTFE seal washer
7	Control cone	Stainless steel 1.4571
8	Valve seat	Stainless steel 1.4571
9	O-ring valve seat	EPDM or PTFE
10	Valve body	Stainless steel CF3M

Dimensions

Body with Flange Connection (DN 25)

Dimensions in mm, unless otherwise stated.

DN	∅ DF	LF	∅ BF	AF	∅ D	A x α	∅ MF
25	115	160	85	18	14	4 × 90°	29.7

Performance Specifications

Flow Characteristics

Fluidic data for flow below seat (DN 25, Seat Size 25, AG2 1300N):

• Theoretical rangeability: 50:1
• Kvs value: 12 m³/h
• Kv value at stroke (%):
  • 5%: 0.35
  • 10%: 0.38
  • 20%: 0.65
  • 30%: 1.0
  • 40%: 1.5
  • 50%: 2.2
  • 60%: 3.4
  • 70%: 5.1
  • 80%: 7.0
  • 90%: 9.4
  • 100%: 12

Operating Limits for Seat Seal

By using plastics (PTFE) as sealing material, the control valves can close tightly (Leakage class VI). Their use is recommended for temperatures ≤ +130 °C. They are not recommended in cases of increased erosion due to demanding process conditions (e.g., cavitation or abrasive media).

Product Design and Assembly

The electromotive linear drive consists of a brushless DC motor, a gear, and a spindle system that transfers the force to the closing element. The integrated electronics are controlled by standard signals. The electromotive linear actuator is designed to provide optimum efficiency, keeping the valve tight and in position even at the maximum specified medium pressure in a powerless standstill.

Integrated Position Controller

The position of the actuator (stroke) is controlled according to the position set-point value. The displacement transducer records the actual position (POS) of the electric linear actuator. The positioner compares the actual position value with the position set-point value (CMD) specified as a standard signal. If there is a system deviation, the electric motor drive is controlled via the actuating variable, and the actual position value is changed accordingly.

Safety Position via Energy Storage

The safety starting position in case of power interruption is realized with the SAFEPOS energy-pack. The desired position is set via the menu. In addition to the end positions (open/closed), any desired intermediate position can be defined. The energy storage has a lifespan of up to 10 years, depending on operating conditions. The storage device is designed as a plug-in module to facilitate replacement.