Burkert Type 2875 Solenoid Proportional Valve | 00239091 00320879 00320878

The Type 2875 Series direct-acting solenoid proportional valves manufactured by Chengyuan Hydraulic are ultra-precision 2/2-way normally closed (NC) fluid control components fully compatible with Burkert industrial standards. Specifically engineered for the continuous, infinitely variable modulation of gases and liquids, this series masters tasks requiring high repeatability and minimal thermal drift. For core part numbers like 00239091 (customized for high-frequency micro-metering) and companion configurations 00320879, 00320878, and 00320877, we utilize a proprietary frictionless flexure-guided armature suspension design. This design completely eliminates stick-slip thresholds typical of sliding-seal variants. Every valve undergoes 100% simulated operational current-to-flow curve (I-Q curve) calibration and bubble-tight bubble-leak checking before delivery, guaranteeing linear sensitivity and delivering proven 100% original-place interchangeability.

Technical Specifications :

• Series Specification: Burkert Type 2875 Standard Proportional Control Valve

• Part Numbers Supported: 00239091 / 00320879 / 00320878 / 00320877

• Circuit Function Topology: 2/2-Way / Normally Closed (NC) / Continuous Proportional Regulation

• Orifice Diameter Grids: 2.0 mm to 9.5 mm (Calibrated precisely per OEM order specifications)

• Port Connection Interfacing: G 3/8 or G 1/2 Female Threaded Ports (Sub-base manifold block mounting available)

• Nominal Command Voltage: 24V DC

• Solenoid Drive Current Grids: 0 – 420 mA / 0 – 750 mA (Optimized via PWM signal tracking)

• Maximum Pressure Handling: Up to 25 bar (2.5 MPa, orifice size and coil wattage dependent)

• Hysteresis Performance Index: $< 1\%$ (When matched with optimized high-frequency PWM driver cards)

• Repeatability & Step Response: Repeatability $< 0.5\%$ of full scale; Step response time $< 25 ms$

• Body Construction Materials: High-density forged brass standard / Premium 316L Stainless Steel options

• Elastomer Sealing Configurations: Premium FKM (Viton) or EPDM options for extensive chemical media compatibility

Key Technical Advantages:

• Frictionless Armature Suspension Mechanics: The standout advantage of the Type 2875 lies in its linkless guide structure. The sliding core is suspended via dual-flat spring elements, preventing any contact with the guide tube wall. This architecture deletes sliding mechanical drag, enabling the core to shift under minuscule milliamp adjustments, choking hysteresis to under 1%.

• High-Linearity I-Q Characteristic Profiling: The internal plunger profile and valve seat geometry are sculpted using fluid dynamics emulation software. As the drive current scales upward linearly, the volumetric flow increases in near-perfect symmetry, significantly simplifying PID closed-loop tuning algorithms within host PLCs.

• Wet-Armature Solenoid with Thermal Ingress Protection: The moving core is completely submerged within the fluid medium, which acts as a natural dampener for silent operation while using the media stream to siphon away coil heat. Coils are epoxy-encapsulated to achieve an IP65 rating, resisting thermal drift during 24/7 high-frequency duty cycles.

• Tight Zero-Current Static Cut-Off Isolation: When power drops to 0 mA, a heavy-duty calibrated return spring forces the FKM seal pad tightly against the mirror-lapped metal orifice rim. This enables the unit to function simultaneously as an isolation shut-off valve, arresting trace fluid seeping under low-to-medium pressure differentials.

Application Areas:

• Medical Devices & Analytical Systems: Precision oxygen-air blending in critical ICU ventilators, and carrier gas dosing regulators for gas chromatography instruments.

• Thermal Processing & Industrial Burners: Exact air-to-fuel ratio control and oxygen flow modulation in manufacturing anneal ovens and gas burners.

• Industrial Coating & Dispensing Assemblies: Micro-metered fluid delivery systems for automated industrial painting bays and precision electronics potting dispensers.

• Semiconductor & CEMS Integration: Purge gas flow control for wafer etching lines and sample gas path switching loops within Continuous Emissions Monitoring Systems.

Expert Maintenance Tips:

• Mandatory Dithered PWM Driver Command: The Type 2875 is a highly sensitive proportional instrument. The 24V DC coil must be modulated via a Pulse Width Modulation (PWM) signal with a dither frequency between 400Hz and 800Hz. Feeding raw, unmodulated 24V DC from a power supply will overheat the coil and freeze the spool due to the absence of micro-vibrations.

• Micro-Filter Installation Standard: Due to the micro-clearances inside the suspended armature track, small scale particles, welding slag, or varnish will seize the mechanism. Installing an upstream filter with an absolute rating of $5 \mu m$ or finer is a strict system requirement.

• Elimination of Pipe Stress Torque: When threading external plumbing into the G 3/8 or G 1/2 connection ports, ensure the pipe fittings are perfectly aligned. Excessive structural torque from mismatched lines can warp the brass valve body by a fraction of a micron, throwing the internal armature off balance and ballooning control hysteresis.