Union Elbow

Union Elbow Product Overview

SIYelectric Union Elbow is designed to connect two tube or pipe lines while changing the flow direction, usually at a 90-degree angle, in instrumentation, fluid, gas, hydraulic, pneumatic, and process systems.

Compared with a straight union connector, a union elbow provides both direction change and removable connection in one fitting. This makes it useful in compact panels, process skids, analyzer systems, hydraulic equipment, and pressure measurement assemblies where tubing needs to turn direction and still remain easy to install or remove.

The union structure supports convenient disassembly during inspection, maintenance, cleaning, or system modification. With proper material, connection size, sealing structure, and pressure rating, it can be used in demanding environments involving pressure, temperature, vibration, oil, gas, water, or compatible chemical media.

How It Works

Compatible Instruments and Components

This union elbow can be used with:

• Pressure transmitters
• Differential pressure transmitter impulse lines
• 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 elbows are often used where tubing from a pressure transmitter, differential pressure transmitter, manifold, gauge valve, or calibration line needs to change direction in a compact installation space.

Typical Application Scenarios

1. Instrument Tubing Direction Change

Used where instrument tubing needs to turn direction while maintaining a removable connection.

Typical examples include:

• Pressure transmitter impulse lines
• Differential pressure transmitter tubing
• Gauge valve outlet tubing
• Calibration tubing
• Analyzer sample lines
• Gas panel tubing

2. Pressure Instrument Assemblies

Suitable for pressure gauge, pressure switch, pressure transmitter, and manifold installations where the connection direction must be adjusted for better layout, visibility, or maintenance access.

It can help connect:

• Pressure transmitters to impulse tubing
• Manifolds to tube lines
• Gauge valves to instrument panels
• Pressure gauges to angled tubing arrangements

3. Hydraulic and Pneumatic Control Lines

Applied in hydraulic power units, pneumatic panels, actuator control circuits, pressure test systems, and compact machinery assemblies where tubing needs a directional change with easy disassembly.

4. Sampling and Analyzer Systems

Used in gas sampling lines, liquid sampling systems, analyzer cabinets, laboratory setups, and process monitoring skids where tubing layout is compact and frequent maintenance may be required.

5. Process Skids and Industrial Fluid Systems

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

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

Key Benefits

Selection Notes

Before selecting a union elbow, confirm:

• Tube or pipe outer diameter
• 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
• Installation direction and available space
• Whether it is used for instrumentation, hydraulic, pneumatic, analyzer, or process piping

Correct selection helps ensure reliable sealing, suitable installation direction, and long-term performance.

Main Advantages

• Provides a compact angled connection for tube and pipe systems.
• Combines elbow routing with convenient union disassembly.
• Suitable for pressure transmitters, gauges, manifolds, valves, sampling systems, and analyzer panels.
• Helps simplify tubing layouts in instrument panels and process skids.
• Supports maintenance, cleaning, inspection, and replacement without rebuilding the whole line.
• Stainless steel options support long-term use in industrial environments.
• Available in different sizes, materials, and connection types according to project requirements.