Article 7 of 10: Inline Transducer Installation for OUF Series Flowmeters

Why Inline Transducers? Precision for High-Pressure Systems

Inline transducers for the OUF Series deliver unmatched accuracy (±0.5%) in high-pressure (up to 4.0MPa) and high-temperature (160°C) applications. Unlike clamp-on or insertion models, they integrate directly into pipelines via flanges, eliminating signal loss from pipe walls. This guide covers flange welding, alignment, and leak-proof sealing for permanent installations.

Tools and Materials Required

• Pipe Cutting Saw: For precise cuts on steel, PVC, or composite pipes.
• Companion Flanges: Match the transducer’s flange rating (e.g., ANSI 150#, PN16).
• Alignment Rods: Ensure flanges are parallel and coaxial.
• Torque Wrench: Tighten bolts evenly (recommended torque: 30–50 Nm).
• Welding Equipment: TIG/MIG welder for steel pipes.
• PTFE Gaskets: High-temperature sealing 

Step 1: Pipeline Preparation

1. Measure and Mark:

o Cut the pipeline to a length of transducer length + 2x gasket thickness + 10mm (e.g., 320mm for a 300mm transducer).
o Deburr cut edges to prevent flow turbulence.

2. Tack Weld Flanges:

o Position companion flanges on both pipe ends using alignment rods.
o Tack weld at 3–4 points to hold flanges in place.

Step 2: Welding Flanges

1. Full Penetration Welds:

o Weld flanges in segments, alternating sides to minimize heat distortion.
o Grind welds smooth to avoid crevices that trap debris.

2. Cooling Phase:

o Allow welds to cool naturally—quenching weakens joints.

Step 3: Installing the Inline Transducer

1. Gasket Placement:

o Position PTFE gaskets between flanges and transducer.

2. Bolt Tightening Sequence:

o Follow a star pattern to distribute pressure evenly.
o Torque bolts to 30 Nm initially, then 50 Nm in three passes.

Steps 1–4: Alternating bolt sequence for uniform sealing.

3. Alignment Check:

o Use a straightedge across flanges—max misalignment: 1mm per 100mm diameter.

Step 4: Signal Cable Connection

1. Wiring:

o Connect upstream (white/red) and downstream (green/black) transducer wires to the OUF-W converter.
o Ground shielding at the converter’s GND terminal.

2. Sealing:

o Apply waterproof gel to cable glands (IP68 rating).

Step 5: Leak Testing and Signal Validation

1. Hydrostatic Test:

o Pressurize the system to 1.5x operating pressure. Check for leaks at gaskets.

2. Signal Verification:

o Navigate to M90: Signal strength >80.0 and Q >70.
o Confirm flow direction matches physical installation (M00/M01).

Common Pitfalls

• Over-Tightening Bolts: Crushes gaskets, causing leaks. Use a torque wrench.
• Misaligned Flanges: Creates uneven flow profiles. Re-cut the pipe if misalignment >2mm.
• Ignoring Thermal Expansion: For steam lines, allow 5mm gap for flange expansion.

Ensure leak-free installations! Get in touch with our certified technicians for complex high-pressure systems!

Next in the Series
In Article 8: Configuring OUF-W Ultrasonic Flowmeters, we’ll explore parameter setup, alarm configuration, and MODBUS integration for seamless SCADA connectivity.