Flapper-Nozzle Assembly

Product Specifications

Technical details and manufacturing context for Flapper-Nozzle Assembly

Definition

The flapper-nozzle assembly is the core sensing and control element within an I/P (current-to-pressure) converter. It translates small electrical current variations into precise pneumatic pressure outputs by modulating the distance between a movable flapper and a fixed nozzle, thereby controlling backpressure in the pneumatic system. This component is typically used in industrial process control applications where accurate pressure regulation is required. The assembly consists of a flapper, a nozzle, and associated seals, with materials including stainless steel, nickel alloy, and synthetic rubber for seals. Key parameters include operating pressure (1.0–1.6 MPa), air flow rate (0.5–2.0 L/min at 0.1 MPa supply), nozzle diameter (0.5–1.5 mm), flapper travel (0.1–0.5 mm), linearity (±1.0% FS within 10–90% of travel), hysteresis (≤0.5% FS at 25 °C), repeatability (±0.2% FS over 100 cycles), supply voltage (24 ±10% V DC for integrated electronics), current output (4–20 mA two-wire loop), operating temperature (-20–85 °C non-condensing), ingress protection (IP54–IP65 per IEC 60529), material grade (316L per ASTM A240), and weight (0.5–1.2 kg depending on configuration). These values are reference ranges and must be verified for the specific model and application. The assembly is designed for use in pneumatic control loops, and its performance directly affects the accuracy and stability of the converter. Proper installation and maintenance are essential to ensure reliable operation. When selecting or replacing this component, it is important to confirm compatibility with the existing system, including pressure ratings, electrical interfaces, and environmental conditions. Always consult the legal manufacturer or supplier for model-specific specifications and standards compliance.

Working Principle

An input current creates a proportional magnetic force on the flapper, moving it closer to or farther from the nozzle orifice. This changes the restriction to air flow from a constant supply, creating a variable backpressure that is amplified to produce the converter's output pressure signal. The flapper-nozzle assembly operates on the principle of a variable restriction: as the flapper approaches the nozzle, the air flow is restricted, increasing backpressure; moving away reduces restriction and lowers backpressure. This mechanical movement is precisely controlled by the electrical input, allowing for accurate conversion of current signals to pneumatic pressure.

Common Materials

Stainless steel, Nickel alloy, Synthetic rubber (seals)

Technical Parameters

Parameter	Typical range	Notes & selection driver
Air Flow Rate	0.5–2.0 L/min	At 0.1 MPa supply pressure
Nozzle Diameter	0.5–1.5 mm	Determines flow gain
Flapper Travel	0.1–0.5 mm	Linear range for control
Linearity	±1.0 %FS	Within 10–90% of travel
Hysteresis	≤0.5 %FS	At 25 °C
Repeatability	±0.2 %FS	Over 100 cycles
Supply Voltage	24 ±10% V DC	For integrated electronics
Current Output	4–20 mA	Two-wire loop
Operating Temperature	-20–85 °C	Non-condensing
Ingress Protection	IP54–IP65	Dust and splash proofIEC 60529
Material	316L	Corrosion resistantASTM A240
Weight	0.5–1.2 kg	Depending on configuration

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Flapper Part
Movable armature that modulates air flow by varying distance from nozzle

Material: Nickel alloy
Nozzle
Fixed orifice that creates air flow restriction with flapper

Material: Stainless steel
Flapper Pivot Part
Provides rotational axis for flapper movement

Material: Stainless steel
Nozzle Seat Part
Secures nozzle and provides sealing surface

Material: Stainless steel

Applied To / Applications

This component is essential for the following industrial systems and equipment:

I/P Converter

View system integration details

Manufacturers of Flapper-Nozzle Assembly

Manufacturer profiles associated with Flapper-Nozzle Assembly.

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Frequently Asked Questions

What is the operating pressure range for this flapper-nozzle assembly?

The reference operating pressure range is 1.0–1.6 MPa. However, the actual allowable range depends on the specific model and application. Always verify with the manufacturer or supplier.

What materials are used in the flapper-nozzle assembly?

The assembly typically uses stainless steel, nickel alloy, and synthetic rubber for seals. The material grade for stainless steel is 316L per ASTM A240, but confirm the exact materials for your model.

What is the typical current output signal?

The assembly is designed for a 4–20 mA two-wire loop output. This is a standard industrial signal, but verify the electrical interface and compatibility with your system.

What ingress protection rating does it have?

The reference ingress protection is IP54–IP65 per IEC 60529, indicating dust and splash proof. Confirm the exact rating for your specific configuration.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification

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pressure:	0 to 100 psig
flow rate:	0.1 to 10 SCFM
temperature:	-20°C to 80°C
slurry concentration:	Not suitable for slurries

Product Specifications

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