Burkert 311810 (Type 2871) is a direct-acting solenoid control valve used as the regulating unit in process control loops. Due to an elastomeric seat seal, the valve closes tight (integrated shut-off function) up to the DN specific nominal pressure. The plunger of the valve is assembled frictionless, which leads to an extraordinary adjustment characteristic. This valve is particularly suitable for demanding control tasks involving high control ranges and dry gases.

General Technical Data

Product Properties	Value
Seal Material	FKM, EPDM
Body Material	Brass, stainless steel
Hysteresis	< 5 %
Repeat Accuracy	< 0.25 % FS
Response Sensitivity	< 0.25 % FS (< 0.1% FS with DN < 0.8 mm)
Setting Range	1:200 (DN 0.8...2), 1:500 (DN 0.05...0.6)
Actuating Time (10...90%)	< 15 ms
Pressure Range	0...12 bar (also applicable for technical vacuum)
Duty Cycle	100 % continuous operation
Operating Voltage	24 V DC (12 V on request)
Power Consumption	Max. 5 W
PWM Frequency	1500 Hz
Degree of Protection	IP65

Circuit Function

Circuit function A (CF A): 2/2-way solenoid proportional control valve, direct-acting, normally closed.

Approvals and Conformities

• North America (USA/Canada): Optional UL Recognized for the USA according to UL 429 (Electrically operated valves). This device is intended to be used with a NEC Class 2 power source or transformer.
• Foods and Beverages/Hygiene: Variants available with compliance to USP (United States Pharmacopeial Convention), FDA (Code of Federal Regulations), and EC Regulation 1935/2004.

Product Structure

1. Adjusting screw (do not adjust!)
2. Valve body
3. Labelling flow direction

Dimensions

Threaded Variant

Port connection	A	B
G 1/8	8 mm	-
NPT 1/8	7 mm	-

Performance Specifications

Exemplary Characteristic Curve

Sizing Recommendation

The dimensioning of the nominal diameter is very important for proportional valves to function properly within the application. The nominal diameter must be selected so that the desired flow range is achieved and, when the valve is fully open, a sufficient portion of the total pressure drop occurs across the valve. Reference value: Δp_valve > 25% of the total pressure drop. If the differential pressure exceeds half the value of the nominal pressure, discontinuities may occur.

Product Operation

Valve control takes place through a PWM signal (pulse-width modulation). The duty cycle of the PWM signal determines the coil current and hence the position of the plunger. The Bürkert control electronics Type 8605 converts an analogue signal to a reference value corresponding to the valve type PWM signal and provides additional functions such as temperature compensation (coil heating), ramp function, and the adjustment of minimum and maximum duty cycle/coil current for the control range.

Installation and Maintenance

WARNING

Risk of injury due to high pressure and escaping medium. Switch off the pressure before working on the device or system. Vent or drain the pipes.

• Prior to installation: Clean pipes and flange connections. Install a dirt trap in the direction of the current before the valve (mesh width 0.02... 0.4 mm, depending on nominal diameter).
• Threaded connection: Use an open-end wrench on the valve body for installation. Do not use the coil as a lever arm.
• Maintenance: The valve operates maintenance-free under normal conditions.