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

Model 338677 features a 0.6 mm orifice, stainless steel body, FKM seal, and NPT 1/8 port connection, operating at 24 V DC.

General Technical Data

Property	Value
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)
Operating voltage	24 V DC (12 V on request)
Power consumption	Max. 5 W
Maximum coil current	220 mA (at 5 W and 24 V coil)
PWM frequency	1500 Hz
Medium temperature	-10 °C...+90 °C (with FKM)
Degree of protection	IP65

Circuit Function

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

Dimensions

INFO

Dimensions in mm. The following figure shows the threaded variant.

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

Performance Specifications

Flow Characteristic

Determination of the Kv value:

• Sub-critical ($p_2 > \frac{p_1}{2}$): $= Q \sqrt{\frac{\rho}{1000\Delta p}}$ (liquids)
• Supercritical ($p_2 < \frac{p_1}{2}$): $= Q \sqrt{\frac{\rho}{1000\Delta p}}$ (liquids)

Exemplary Characteristic Curve

WARNING

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: $\Delta p_{valve} > 25%$ of the total pressure drop.

Product Operation and Installation

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.

TIP

Any installation position is permitted, preferably with the actuator facing up. Use an open-end wrench on the valve body for installation. Do not use the coil as a lever arm.

PWM Frequency Settings (Type 2871):

• 24 V, 5 W: $f_{LO}$ 1400 Hz, $f_{HI}$ 1500 Hz, $I_{max}$ 220 mA
• 12 V, 5 W: $f_{LO}$ 1400 Hz, $f_{HI}$ 1500 Hz, $I_{max}$ 420 mA