BURKERT 53969 (Type 0331) is a direct-acting, media-separated 3/2-way pivoted armature solenoid valve configured in circuit function C (normally closed). It features a brass valve body, EPDM seals, and a 3.0 mm nominal orifice. Designed for sub-base installation via the Bürkert-specific flange interface (32 mm x 46 mm, version A2), this complete valve unit operates on 24 V DC with a rated operating pressure range from 0.00 bar to 10.00 bar. The water flow coefficient Kv reaches 0.12 m³/h, and the standard gas flow rate QNn is 130 l/min.

The pivoted armature mechanism isolates the magnetic actuator from the fluid path using a flexible diaphragm barrier. This physical separation prevents medium contact with metallic coil components, making Type 0331 suitable for aggressive or sensitive media within a fluid temperature span of -30 °C to +90 °C. The valve assembly includes an integrated manual override for commissioning and function tests, an epoxy-encapsulated Class H coil, and an enclosed DIN EN 175301-803 Form A cable plug achieving IP65 enclosure protection.

Operating Principle and Pivoted Armature Technology

Type 0331 uses a pivoted armature drive where the magnetic core tilts rather than slides within the media chamber. Because the armature does not slide inside the fluid, the construction eliminates sliding seal friction, particle entrapment, and premature mechanical wear. The separating diaphragm isolates the solenoid actuator from the fluid cavity, ensuring clean fluid handling and chemical resistance.

The integrated manual override is positioned on the valve top, allowing manual switching during commissioning, emergency override, or system maintenance without applying electrical power. To prevent accidental manual triggering in critical processes, an optional circlip accessory can be fitted to mechanically lock the manual lever.

Circuit Functions and Port Assignment

Article 53969 operates under Circuit Function C: a direct-acting 3/2-way valve that is normally closed in its de-energized state. In this unpowered state, pressure supply port 1 (P/NC) is shut off, while service outlet port 2 (A/OUT) vents directly through exhaust port 3 (R/NO). Upon energizing the 24 V DC coil, the pivoted armature shifts: inlet port 1 connects to outlet port 2, and exhaust port 3 is closed.

Circuit Function	Valve Type Description	Port 1	Port 2	Port 3
WW A	2/2-way direct-acting, normally closed	P	A	—
WW B	2/2-way direct-acting, normally open	—	B	P
WW C (53969)	3/2-way direct-acting, normally closed	P	A	R
WW D	3/2-way direct-acting, normally open	R	B	P
WW E	3/2-way mixing valve	P1	A	P2
WW F	3/2-way distribution valve	A	P	B
WW T	3/2-way direct-acting, universal flow direction	NC	IN/OUT	NO

Port Mapping for Article 53969

On the standard Bürkert sub-base flange interface, Port 1 corresponds to fluid supply (P), Port 2 serves as working output (A), and Port 3 acts as the exhaust or return channel (R).

Material Specifications and Chemical Resistance

The physical construction of Type 0331 utilizes high-grade engineering polymers and metallurgies matched to demanding fluid conditions:

Item	Component	Material (Article 53969)	Family Material Options
1	Solenoid coil	Epoxy encapsulation	Epoxy (Class H insulation)
2	Diaphragm	EPDM (70 Shore A)	EPDM, FKM, FFKM, NBR
3	O-ring seals	EPDM	EPDM, FKM, FFKM, NBR
4	Valve seat	Brass	Brass, Stainless steel (1.4401), PP, PEEK
5	Valve body	Brass	Brass, Stainless steel (1.4401), PP, PEEK, PVDF

EPDM sealing material is chemically resistant to alkalis, low-to-medium concentration acids, alkaline washing solutions, and bleaching lyes. For mineral oils or fuel applications, NBR or FKM configurations must be selected instead.

Dimensions and Sub-Base Flange Interface

BURKERT 53969 is built on the standard Bürkert sub-base flange interface (SFB version A2), enabling direct mounting onto multi-station manifolds or custom control blocks. Key structural dimensions:

• Interface base pattern: Bürkert flange 32 mm x 46 mm (version A2)
• Installation length: 46 mm
• Metal body height (H): 18 mm
• Total unit weight: 0.47 kg
• Fluidic ports: 3 ports located on sub-base interface (P, A, R)

Performance and Electrical Data

In standard DC operation, Type 0331 coils consume 11 W cold and 8 W warm, delivering 100% ED continuous duty rating on brass and stainless steel bodies.

Characteristic	Specification (53969)	Family Range (Type 0331)
Nominal orifice (DN)	3.0 mm (1/8")	DN 2.0 mm to DN 4.0 mm
Flow factor Kv (Water)	0.12 m³/h	0.08 m³/h (DN 2 DC) to 0.18 m³/h (DN 4 AC)
Standard flow rate QNn (Gas)	130 l/min	—
Operating pressure range	0.00 – 10.00 bar	0 – 16 bar (DN 2), 0 – 10 bar (DN 3), 0 – 5 bar (DN 4)
Vacuum capability	Down to -0.98 bar	-0.98 bar to rated limits across all seal types
Switching time: opening	10–20 ms	8–15 ms (AC), 10–20 ms (DC)
Switching time: closing	10–20 ms	8–15 ms (AC), 10–20 ms (DC)
Voltage rating	24 V DC (±10% tolerance)	12 V DC, 24 V DC, 24 V/50 Hz, 110 V/50 Hz, 230 V/50 Hz
Power consumption (DC)	Cold: 11 W, Warm: 8 W	Standard DC: 11 W / 8 W; AC: 30 VA inrush, 15 VA / 8 W hold
Medium viscosity	Max. 37 mm²/s	Max. 37 mm²/s

Measurement Conditions for Switching Times

Switching times are measured according to DIN standards at +20 °C and 6 bar pressure at the valve outlet. Opening corresponds to a pressure build-up from 0% to 90%, while closing corresponds to a pressure reduction from 100% down to 10%.

Pressure Limits in Alternative Circuit Functions

The internal compression springs in Type 0331 valves are calibrated specifically for each circuit function. When a valve built for one function is connected in a different configuration, the maximum allowable operating pressure adjusts according to internal spring bias:

Original Function	DN	Permissible Working Pressure in New Function [bar] (Metal Body, 8 W / 11 W)
		A	B	C	D	E	F
C (53969 base)	DN 2	16 bar	1.5 bar	16 bar	1.5 bar	1.5 bar	16 bar
C (53969 base)	DN 3	10 bar	1.0 bar	10 bar	1.0 bar	1.0 bar	10 bar
C (53969 base)	DN 4	5 bar	0.8 bar	5 bar	0.8 bar	0.8 bar	5 bar
D	DN 3	2.5 bar	10 bar	2.5 bar	10 bar	2.0 bar	3.0 bar
T	DN 3	6.0 bar	6.0 bar	6.0 bar	6.0 bar	6.0 bar	6.0 bar

Electrical Connection and Installation Guidelines

BURKERT 53969 is supplied with standard terminal tags matching DIN EN 175301-803 Form A. An enclosed cable plug provides IP65 protection when secured with its central tightening screw.

• Orientation: Any mounting position is permitted, with actuator in upright position preferred.
• Ambient temperature limit: Maximum +55 °C.
• Flow direction: Below seat configuration.
• Fluid conditions: Solid particles must be filtered upstream to prevent seating interference.

Safety Instructions for Servicing

Before conducting maintenance or dismounting the valve, depressurize and fully drain fluid lines. Disconnect power supplies and ensure systems cannot be re-energized accidentally. Protective earth conductors must remain continuously connected.

Combinable Accessories and Manifolds

Type 0331 modular sub-base valves integrate with factory manifold assemblies and auxiliary electronics:

• Cable plug Type 2518 (Form A): Available in versions without wiring (0–250 V AC/DC, article 314802), with indicator LED (12–24 V AC/DC, article 314812), with LED and varistor (article 314820), or with integrated bridge rectifier.
• Cable plug Type 2509 (Form A): Industrial standard cable plug without internal circuitry (0–250 V AC/DC, article 137943).
• Accidental operation protection: Mechanical circlip (article 013372) mounts over the manual override lever to prevent inadvertent actuation.
• G 1/4 Sub-base Manifolds: Available in anodized aluminium, brass, and stainless steel for multi-valve stations ranging from 1 to 8 positions (e.g., 2-position aluminium manifold article 005045, length 69 mm; 4-position aluminium manifold article 005294, length 143 mm).
• Manifold Accessories: Stainless steel blanking cover plate for unassigned valve positions (article 265294 with FKM seal), anodized aluminium cover plate (article 005625 with NBR seal), and inter-manifold joining nipples.