Burkert 367609 Type 2861 is an extremely compact, direct-acting 2/2-way solenoid proportional control valve. It features a 1.0 mm orifice, stainless steel body, and FKM (fluor rubber) seals. Designed as an actuator for closed control loops (pressure, flow, temperature), it offers high dynamics and a good control range (1:25). This specific model operates on 12V DC with a G 1/8 internal thread process connection.

General Technical Data

Property	Value
Circuit function	A (2/2-way, direct-acting, normally closed)
Orifice size	1.0 mm
Port connection	G 1/8 internal thread
Body material	Stainless steel
Seal material	FKM (Fluor rubber)
Operating voltage	12 V DC
Pressure range	-1 to 10 bar
Medium temperature	-10 °C to +90 °C
Ambient temperature	Max. +55 °C
Kv value (water)	0.027 m³/h
Setting range	1:25
Hysteresis	< 5%
Repeat accuracy	< 1% FS
Response sensitivity	< 1% FS
Actuating time (10...90%)	< 15 ms
PWM frequency	650...800 Hz
Degree of protection	IP65

Approvals and Conformities

• FDA: All wetted materials are compliant with the Code of Federal Regulations published by the FDA (Food and Drug Administration, USA) according to the manufacturer’s declaration.
• EC Regulation 1935/2004: All wetted materials are compliant with EC Regulation 1935/2004/EC according to the manufacturer’s declaration.
• Oxygen: Optional suitability for use with gaseous oxygen, according to the manufacturer's declaration.

Dimensions

Threaded body G 1/8(Dimensions in mm)

Performance Specifications

Flow Characteristic

Determination of the Kv value:

• Sub-critical ($p_2 > \frac{p_1}{2}$):
  • Liquids: $K_v = Q \sqrt{\frac{\rho}{1000\Delta p}}$
  • Gases: $K_v = \frac{Q_N}{514}\sqrt{\frac{T_1\rho_N}{p_2\Delta p}}$
• Supercritical ($p_2 < \frac{p_1}{2}$):
  • Liquids: $K_v = Q \sqrt{\frac{\rho}{1000\Delta p}}$
  • Gases: $K_v = \frac{Q_N}{257p_1}\sqrt{T_1\rho_N}$

Exemplary Characteristic Curve

Sizing 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.

Otherwise, an ideal, linear valve characteristic is deformed into a curved system characteristic. If the differential pressure (difference between inlet and outlet 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.