Burkert Type 2871 (SKU 20053048) is a direct-acting 2/2-way solenoid proportional control valve used as the regulating unit in control loops. This specific model features a 1.60 mm orifice, stainless steel body, EPDM seat seal, and a flange connection (Bürkert flange 20 x 20 version A1). 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.

Product Structure

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

General Technical Data

Product properties
Material
Seal	EPDM (FKM available in series)
Body	Stainless steel (Brass available in series)
Performance data
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	-1 to 6 bar (SKU specific)
Duty cycle	100% continuous operation
Electrical data
Operating voltage	24 V DC
Power consumption	Max. 5 W
PWM frequency	800 - 1000 Hz (SKU specific)
Medium data
Operating medium	Neutral gases, liquids on request
Medium temperature	-30 °C...+90 °C (with EPDM)
Viscosity	Max. 21 mm²/s (21 cSt)
Environment and installation
Installation position	As required, preferably with actuator upright
Ambient temperature	Max. +55 °C
Degree of protection	IP65

Circuit Function

Circuit function (CF)	Description
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).
• USP: United States Pharmacopeial Convention (USP). All wetted materials are biocompatible according to the manufacturer's declaration.
• FDA: FDA – Code of Federal Regulations. All wetted materials are compliant with the Code of Federal Regulations published by the FDA.
• EC Regulation 1935/2004: All wetted materials are compliant with EC Regulation 1935/2004/EC according to the manufacturer's declaration.

Dimensions

Performance Specifications

Flow Characteristic

Determination of the $K_v$ value:

Pressure drop	$K_v$ value for liquids [m³/h]	$K_v$ value for gases [m³/h]
Sub-critical $p_2 > \frac{p_1}{2}$	$= Q \sqrt{\frac{\rho}{1000\Delta p}}$	$= \frac{Q_N}{514}\sqrt{\frac{T_1\rho_N}{p_2\Delta p}}$
Supercritical $p_2 < \frac{p_1}{2}$	$= Q \sqrt{\frac{\rho}{1000\Delta p}}$	$= \frac{Q_N}{257p_1}\sqrt{T_1\rho_N}$

Exemplary Characteristic Curve

Note

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, on the one hand, the desired flow range is achieved and, on the other hand, 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

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

DANGER!

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.
• For valve body with flange connection: check seals are seated correctly.

NOTE!

• Do not uninstall proportional valve.
• Adjusting screw (see Product Structure) do not adjust.
• Do not use the coil as a lever arm.

Prior to installation

• Clean pipes and flange connections.
• Dirt trap in the direction of the current before the valve (mesh width 0.02... 0.4 mm, depending on nominal diameter).
• For valve body with flange connection: check the seals are correctly seated on the underside of the valve body.

Install valve on base block (flange connection)

• Fasten the valve to the base block using both fastening screws.
• Tightening torque 0.8...1.2 Nm.