BURKERT 56797 (Type 0131) is a direct-acting 2/2-way plunger solenoid valve engineered with circuit function A (normally closed, inlet port 1 P/NC) and complete physical media separation. The valve design hermetically isolates process media from the solenoid actuator assembly, preventing corrosion and deposition on magnetic components when handling aggressive liquids. Delivered as a complete valve assembly, article 56797 integrates a PVC (polyvinyl chloride) body, EPDM seat and external sealing, DN20 orifice, and G 3/4 internal thread ports, operating across a differential pressure range from 0.00 bar up to 0.50 bar on 230 V AC 50 Hz power.

Technical Specifications

Technical Attribute	Specified Value
Article Number	56797
Valve Type Family	0131
Construction Type	Complete valve, media-separated
Circuit Function	A (2/2-way, normally closed, inlet P/NC)
Actuation Principle	Plunger valve (direct-acting)
Orifice Size (DN)	20.0 mm (3/4")
Port Connection 1	Internal thread G 3/4
Body Material (Wetted)	PVC (Polyvinyl chloride)
Seat & External Seal Material	EPDM (Ethylene-propylene-diene rubber)
Operating Pressure Range	0.00 bar to 0.50 bar (liquid max. 0.5 bar)
Flow Capacity Kv (Water)	6.0 m³/h
Nominal Flow QNn (Air/Gas)	6,400 l/min
Power Supply	230 V AC (50 Hz), tolerance ±10%
Coil Technology	Standard coil without Kick and Drop electronics
Operating Duty	Continuous operation (DIN VDE 0580)
Electrical Connection	Plug pattern Form A to DIN EN 175301-803
Included Cable Plug	Enclosed (e.g., Bürkert Type 2518)
Ingress Protection	IP65 (with properly mounted cable plug)
Manual Override	Integrated mechanical locking pin
Fluid Viscosity Limit	Up to 37 mm²/s

Media Compatibility and Operating Limits

BURKERT 56797 combines a rigid PVC body with resilient EPDM elastomeric sealing, providing dedicated resistance to alkalis, alkaline washing solutions, and bleaching lyes within defined thermodynamic limits.

Operating Parameter	Permissible Range / Value
Fluid Temperature (PVC / EPDM)	-10 °C to +50 °C
Ambient Temperature	-10 °C to +50 °C
Storage Temperature	-10 °C to +50 °C
Maximum Medium Viscosity	37 mm²/s
Permissible Fluid Velocity (DN 20.0)	Max. 3.0 m/s

Functional Safety Recommendation

High pressure surges occur when handling liquids under elevated differential pressure and high flow velocity. During extended operational idle periods, operate the valve at least 1 to 2 times daily to ensure ongoing functional responsiveness.

Circuit Function

Article 56797 operates under circuit function A: a direct-acting 2/2-way solenoid valve that remains normally closed in its de-energized rest state. Fluid entering pressure inlet 1 (P/NC) is blocked by the EPDM seat seal against the valve seat. When electrical voltage is applied to the 230 V coil, the plunger actuator retracts, unseating the seal and opening the flow passage to outlet port 2 (A).

Type Label Structure

The product label on Type 0131 solenoids provides complete tracking and technical classification data directly on the actuator housing.

Position	Description	Value on Article 56797
1	Valve Type	0131
2	Circuit Function	A
3	Orifice Diameter	20.0 mm
4	Sealing Material	EPDM
5	Body Material	PV (PVC)
6	Connection Type	G 3/4
7	Pressure Range (PN)	0 – 0.5 bar
8	Active Coil Power	Rated coil power at working temp.
9	Voltage Frequency	50 Hz
10	Operating Voltage	230 V AC
11	Manufacturing Code	Internal manufacturing reference
12	Article Order Number	56797

Mechanical Installation

Installation position is universal, though orientation with the solenoid actuator upright on top is recommended. Prior to line installation, flush pipelines thoroughly to eliminate foreign particulate matter. Install an upstream dirt trap or strainer with mesh size ≤ 500 µm directly ahead of the valve inlet.

Installation requires three sequential steps on union connections:

1. Insert the pipe connection fitting.
2. Position the sealing O-ring correctly in its groove.
3. Tighten the union nut evenly by hand only.

Mechanical Precautions

Do not use the solenoid coil as a lever arm during assembly or line tightening. The valve body must never be subjected to pipeline tensile or bending stresses. For versions utilizing adhesive PVC bonding sleeves, apply Tangit special adhesive. Ensure joint sealants or adhesive compounds do not enter the interior cavity of the valve.

Flow direction must follow the markings on the body: from inlet P to outlet A (circuit function A, NC).

Manual Override Operation

BURKERT 56797 is equipped with an integrated mechanical manual override allowing manual actuation during commissioning or maintenance.

To actuate the valve manually, press down the manual override pin and rotate it 90° clockwise until it engages its stop position.

Operational Restriction

When the manual override is rotated and locked in its override position, the valve cannot be actuated electrically. Ensure all O-rings remain properly seated around the manual override pin; loss or displacement of O-rings causes external leakage of process media.

Electrical Connection

Prior to electrical installation or servicing, isolate power to the circuit and verify zero-voltage state.

Electrical connection is made via an enclosed cable plug compliant with DIN EN 175301-803 Form A (such as Bürkert Type 2518):

• Verify supply voltage and frequency match the type label (230 V AC, 50 Hz, ±10%).
• Always connect the protective earth conductor (PE) to the ground terminal and verify electrical continuity to prevent electric shock hazards.
• Ensure the interface flat profile seal (Item 2) is positioned flat between the coil terminal face and the connector plug.
• Fasten the central fixing screw with a maximum tightening torque of 1.0 Nm to secure IP65 ingress protection.

Troubleshooting

Before undertaking component disassembly, confirm pipeline cleanliness, correct voltage feed, applied operating pressure, and unconstrained piping geometry.

Fault Condition	Possible Cause	Corrective Action
Valve does not actuate	Solenoid coil interrupted or short circuit	Check coil continuity; replace coil assembly if open-circuit
	Line pressure exceeds 0.50 bar limit	Adjust operating pressure within the 0.00 – 0.50 bar range
	Manual override locked in engaged position	Rotate manual override 90° counter-clockwise to unlock
Valve does not close	Internal valve chamber or seat contaminated	Disassemble and clean valve interior; inspect strainer
	Manual override locked in engaged position	Disengage and release manual override pin

Spare Parts Kits

Field replacement components for Type 0131 are structured into factory-defined maintenance kits.

Available spare part sets:

• Item 1: Coil set (complete magnetic actuator coil)
• Item 2: Actuator set (plunger core and internal actuating components)
• Item 3: Wearing part set (diaphragm, seat seal, and interface O-rings)

When ordering replacement parts, specify the exact kit item number and the full device article number: 56797.

Logistics and Disposal

Store the valve in its original packaging between -10 °C and +50 °C, shielded from moisture, dust, ultraviolet radiation, and direct sunlight. Protect connection ports with protective caps until line installation.

When returning devices that have been exposed to operating media, Bürkert requires a completed and valid Contamination Declaration prior to testing or repair. Unserviceable electronic assemblies and contaminated valve bodies must be separated and disposed of in accordance with national environmental and electronic waste regulations.