Union Connector

Union Connector Product Overview

SIYelectric Union Connector is designed to connect two tube or pipe lines in instrumentation, fluid, gas, hydraulic, pneumatic, and industrial process systems.

A union connector is mainly used to provide a straight inline connection between two compatible tube or pipe ends. Compared with a permanent welded or fixed threaded connection, the union structure allows easier installation, disassembly, inspection, and replacement, which is useful for systems that may require future maintenance or modification.

If different sizes are required, a reducing union connector can be selected to transition between two tube or pipe diameters. For standard union connectors, both ends are usually the same size.

How It Works

Compatible Instruments and Components

This union connector can be used with:

• Pressure transmitter impulse lines
• Differential pressure transmitter tubing
• Pressure gauges
• Pressure switches
• Gauge valves
• Needle valves
• Ball valves
• Instrument manifolds
• Calibration lines
• Test lines
• Sampling lines
• Analyzer systems
• Hydraulic and pneumatic control panels

For pressure measurement systems, union connectors are often used to join tubing sections between pressure transmitters, manifolds, gauge valves, calibration equipment, and process connections.

Typical Application Scenarios

1. Instrument Tubing Extension

Used when two tube sections need to be joined in pressure measurement, flow measurement, sampling, or analyzer systems.

Typical examples include:

• Pressure transmitter impulse tubing
• DP transmitter connection lines
• Calibration tubing
• Analyzer sample lines
• Gas panel tubing

2. Pressure Instrument Assemblies

Suitable for pressure gauge, pressure switch, and pressure transmitter installations where tubing or piping needs to be connected, extended, or removed during maintenance.

It can help connect:

• Pressure gauges to tubing lines
• Transmitters to manifolds
• Gauge valves to process lines
• Calibration ports to test equipment

3. Hydraulic and Pneumatic Control Lines

Applied in hydraulic power units, pneumatic panels, actuator control circuits, and pressure test systems where inline tube connection and easy maintenance are required.

4. Sampling and Analyzer Systems

Used in gas sampling lines, liquid sampling systems, analyzer cabinets, and laboratory setups where tube sections may need to be disconnected for cleaning, inspection, or replacement.

5. Process Skids and Industrial Fluid Systems

Suitable for dosing skids, filtration units, gas panels, water treatment modules, chemical process equipment, and compact industrial assemblies.

For corrosive media, high-pressure service, or high-temperature applications, material, connection size, sealing method, and pressure rating should be confirmed before selection.

Key Benefits

Selection Notes

Before selecting a union connector, confirm:

• Tube or pipe outer diameter
• Whether both ends are the same size or different sizes
• Connection type, such as tube fitting, threaded, or compression type
• Material grade, such as SS304 or SS316
• Working pressure
• Working temperature
• Process medium
• Required sealing method
• Whether it is used for instrumentation, hydraulic, pneumatic, analyzer, or process piping

Correct selection helps ensure reliable sealing, stable pressure performance, and convenient maintenance.

Main Advantages

• Provides a clean inline connection for tube and pipe systems.
• Suitable for pressure transmitters, gauges, manifolds, valves, sampling systems, and analyzer panels.
• Helps simplify tubing layouts in instrument panels and process skids.
• Supports convenient disassembly during inspection, cleaning, calibration, or replacement.
• Stainless steel options support long-term use in industrial environments.
• Available in different sizes, materials, and connection types according to project requirements.