BURKERT 322509 (Type 6281) is a servo-assisted 2/2-way solenoid valve designed for neutral liquids and gases. Operating with circuit function A (normally closed), the valve utilizes a brass body conforming to DIN EN 50930-6, an internal G 3/8 process connection, and an integrated manual override lever for commissioning and servicing. It requires a minimum differential pressure of 0.2 bar to open, reaching its full flow opening at a differential pressure of 0.5 bar, with a maximum operating pressure rating of 16 bar.

Electrically operated via a 24 V AC (50/60 Hz) central screw-mounted coil system, the valve is rated for 100% continuous duty. The sealing system features NBR elastomer seals suitable for medium temperatures between -10 °C and +80 °C. The flow coefficient Kv for water is 1.9 m³/h, and the gas flow capacity QNn is 2050 l/min. Electrical connection is implemented using an industry standard Form A plug pattern according to DIN EN 175301-803, achieving IP65 ingress protection when properly plugged.

Technical Specifications

Specification Parameter	Value
Article Number	322509
Valve Type	6281 EV
Circuit Function	A (2/2-way valve, normally closed)
Orifice Size (DN)	10 mm
Pilot Control Orifice	1.2 mm
Port Connection	G 3/8 internal thread
Nominal Pressure Range	0.2 to 16 bar (PN 16)
Flow Value Kv (Water)	1.9 m³/h (measured at +20 °C, 1 bar delta-P)
Flow Value QNn (Gas)	2050 l/min
Body Material	Brass according to DIN EN 50930-6
Seal Material	NBR (Nitrile rubber)
Operating Voltage	24 V AC (50/60 Hz)
Voltage Tolerance	±10%
Coil Power (AC)	Inrush: 24 VA; Holding: 14 VA (8 W) / 16 VA (7 W)
Thermal Insulation Class	Polyamide coil class B
Duty Cycle	100% ED continuous operation
Switching Time (Opening)	0.1 to 1.5 s
Switching Time (Closing)	0.2 to 4.0 s
Medium Temperature	-10 °C to +80 °C
Maximum Ambient Temperature	+55 °C
Installation Length	50 mm
Weight	0.40 kg
Manual Override	Integrated manual hand lever

Materials and Construction

The internal fluid path and moving parts utilize corrosion-resistant metallurgy and engineering polymers.

Item	Component	Material
1	Solenoid coil	Polyamide (PA)
2	Stopper	Stainless steel 1.4113
3	Shading ring	Copper (Cu)
4	Magnetic core / plunger	Stainless steel 1.4113
5	O-ring	NBR
6	Core seal	NBR
7	Spring	Stainless steel 1.4310
8	O-ring	NBR
9	Diaphragm	NBR
10	Diaphragm holder	PPS-GF40
11	Valve body	Brass acc. to DIN EN 50930-6

Dimensional Data

Article 322509 belongs to the standard threaded brass body family with DN 10 and coil size 5 (32 mm width).

DN	G Thread	A (mm)	B (mm)	C (mm)	D (mm)	E (mm)	F1 (mm)	L (mm)	SW (mm)
10	G 3/8	83.1	94.1	32	44	22	12	50	22

Coil dimensions for coil size 5 (32 mm):

• Width H: 32 mm
• Core offset J: 20.5 mm
• Overall height K: 45 mm
• Length M: 41 mm
• Height offset O: 3.4 mm

Manual Override Operation

Article 322509 includes an integrated manual lever located directly below the solenoid coil on the valve housing:

1. To operate the valve manually, rotate the hand lever into the vertical position beneath the solenoid.
2. When the hand lever is actuated in the open position, the valve cannot be switched electrically.
3. Return the hand lever to the horizontal closed position to re-enable electric pilot switching.

Operational Restriction

Do not over-rotate the hand lever beyond its defined detents. Applying excessive force to the lever can damage the internal manual override mechanism.

Electrical Connection and Solenoid Installation

The solenoid coil must be mounted securely to the core guide tube before electrical energization. Powering the coil without being assembled to the valve body causes severe overheating and failure.

Assembly Procedure and Torques

1. Slide the coil housing onto the core guide tube, ensuring the anti-twist mechanism and O-ring are seated correctly.
2. Screw the fastening nut onto the core guide tube using an open-end wrench.
3. Tighten fixing nut (solenoid type AC10, 32 mm width) to exactly 5 Nm.
4. Connect the DIN EN 175301-803 Form A cable plug (such as Type 2518 or Type 2509, ordered separately).
5. Secure the cable plug central screw to a maximum torque of 1 Nm.
6. Verify that the protective earth (PE) terminal provides electrical continuity between the solenoid housing and the valve brass body.

Installation and Operating Conditions

Pipeline Preparation

Clean pipelines thoroughly of welding residues and debris before mounting the valve. Install an upstream dirt trap or strainer with a mesh size of ≤ 500 µm directly ahead of port 1 (P).

• Flow direction: Observe the flow direction arrow marked on the brass valve body (flow above seat from port 1 to port 2).
• Mounting orientation: Universal orientation, preferably with the solenoid actuator upright.
• Differential pressure: A minimum differential pressure of 0.2 bar is strictly required across the inlet and outlet to lift the pilot armature and allow servo operation. Full cross-sectional opening occurs at 0.5 bar differential.
• Environmental limitations: Ambient operating temperature must remain at or below +55 °C.

Spare Parts and Ordering Configuration

Original replacement parts can be ordered as grouped sets by specifying the set reference and valve article number 322509:

• SET 1: Solenoid coil package
• SET 3: Plunger armature and core guide assembly
• SET 7: Diaphragm and sealing wear kit

Related Brass DN 10 Standard Variants with Manual Override

Article No.	Port	DN	Kv (m³/h)	Pressure Range (bar)	Voltage / Frequency
322505	G 1/4	10	1.5	0.2 to 16	24 V DC
322506	G 1/4	10	1.5	0.2 to 16	24 V AC (50/60 Hz)
322507	G 1/4	10	1.5	0.2 to 16	230 V AC (50/60 Hz)
322508	G 3/8	10	1.9	0.2 to 16	24 V DC
322509	G 3/8	10	1.9	0.2 to 16	24 V AC (50/60 Hz)
322510	G 3/8	10	1.9	0.2 to 16	230 V AC (50/60 Hz)