Burkert Type 2871 direct-acting solenoid control valve is used as the regulating unit in 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 such as high control range and dry gases.

Features include an excellent range, very good response, and a compact valve design. It is available in orifice sizes from 0.05 to 2.0 mm with port connections of 1/8" or sub-base.

General Technical Data

Product properties
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 (1000 Hz for high differential pressure variant)
Medium temperature	-10 °C...+90 °C (with FKM), -30 °C...+90 °C (with EPDM)
Viscosity	Max. 21 mm²/s (21 cSt)
Degree of protection	IP65

Circuit Function

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

Dimensions

Note

Dimensions in mm.

Performance Specifications

Flow Characteristic

Determination of the Kv value:

Pressure drop	Kv value for liquids [m³/h]	Kv value for gases [m³/h]
Sub-critical p2 > p1/2	= Q √(ρ / 1000Δp)	= (QN / 514) √(T1ρN / p2Δp)
Supercritical p2 < p1/2	= Q √(ρ / 1000Δp)	= (QN / 257p1) √(T1ρN)

Characteristic Curve

Reference Value

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 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 (difference between inlet and outlet pressure) exceeds half the value of the nominal pressure, discontinuities may occur.

Installation & Operation

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.

• Installation position: Any installation position, preferably with the actuator facing up.
• 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 for installation. Do not use the coil as a lever arm. Hold the proportional valve with an open-end wrench on the valve body.

Control Electronics

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.

PWM Frequency

For the standard variant, the PWM frequency is 1500 Hz. For the high differential pressure variant (e.g., SKU 238939), the PWM frequency is 1000 Hz. The setting range for the high differential pressure variant is 1:100.