HX Inspection Tool Problem Statement.pdf

Fluor Marine Propulsion, LLC Post Office Box 79 West Mifflin, PA 15122-0079

UNCLASSIFIED

Scope of Work for Heat Exchanger Inspection Tool

The Buyer is currently investigating small, compact heat exchangers (HX) fabricated by additive manufacturing (AM) using Alloy 625 Inconel. Inspection solutions (e.g., probes or other methods) are needed for smaller tube diameters than those typically used in traditional manufacturing. This scope of work seeks to obtain information on inspection capabilities at smaller tube sizes. While ultrasonic (UT) immersible probes have been previously considered, any method capable of detecting the specified flaws of interest will be evaluated.

Desired Inspection Capabilities

The inspection method must detect the following flaws (both post manufacture and in-service) within the HX matrix. Although detection from the inside diameter (ID) of a tube-like feature using a traditional probe is assumed, the scope does not prescribe a specific approach.

Alternative methods capable of identifying these degradations are also acceptable.

1. Circumferential volumetric flaw*

2. Axial volumetric flaw*

3. Circumferential crack*

4. Axial crack*

5. Voids (printing errors, can be symmetric and non-symmetric volumetric defects)

6. Delamination

7. Degradation (pitting, wear, surface cracks) caused during use

8. Wall-thickness measurement

* Items with an asterisk (*) may occur in the ID, OD and webbing

Description of Application

The cross-sectional geometry of a conceptual heat exchanger design consists of circular tubes interconnected by ligaments or continuous webbing along their length. These ligaments create additional non-circular flow paths between the tubes. Assuming the use of traditional probes, these would be inserted inside the circular tube-like path. The flow path could either be straight or have a gentle curvature. Probes or inspection methods to perform post printing and in-service inspections for a variety of tube sizes are needed, as indicated in the following list.

• Tube ID – 0.100 to 0.400 inch

• Wall thickness – 0.010 to 0.050 inch (about 10-15% of tube ID)

• Surface roughness – 10 to 200 min Ra

• Material – Alloy 625 Inconel

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TECHNICAL QUESTIONS FOR VENDOR

1. List each inspection probe or method you offer that can detect any of the eight specified flaw types inside of a 0.400 or smaller tube ID (and attached webbing). For each probe or method, indicate the following:

a. The smallest tube ID that can be inspected.

b. Which defect types can be detected.

c. If the probe or method can detect all eight defect types, what is the minimum tube ID at which a comprehensive detection is possible.

d. The inspection method (i.e., eddy current, ultrasonic, etc.).

2. How do tube ID and wall thickness affect the minimum resolvable defect size for each technique (UT, EC, etc.)? What is the minimum resolvable defect for each technique at different tube IDs and wall thickness?

3. What are the minimum and maximum wall‑thicknesses that can be measured accurately? Specify the expected measurement accuracy (± %). How is this impacted by tube ID and probe technique?

4. How does surface roughness (10–200 min Ra) impact the following? The surface on the probe side (the cold flow path surface) may be smoother than the other surfaces.

a. Signal‑to‑noise (S/N) ratio

b. Defect resolution

c. Ability to interrogate the far side of the tube wall?

5. What is the minimum defect size that can be reliably detected for each flaw type at the smallest tube ID and at the maximum wall thickness?

6. What webbing lengths (distance between adjacent tubes) can be inspected reliably from the tube ID or with another method? Identify any challenges for detecting defects in the webbing.

7. What degree of bend radius/curvature in the flow path (tube) is allowable to maintain ability to feed an inspection probe through the entire flow path (tube)? If this cannot be answered at this time, provide probe dimensions, and indicate whether any portions are flexible.

8. Can the inspection probes or methods be used on irregular shaped flow paths (non-circular channels)? If so, describe any limitations.

9. Can one probe or method be used for axial and circumferential flaw detection or are multiple probes required?

10. Are you able to develop, test, and qualify a probe(s) or method that would meet the desired tube ID requirements (0.100 to 0.400 inches)? If so, what minimum size tube would the probe or method support and what eight specified flaw types can be detected with this (these) probe(s) or methods?

11. If available, include drawings or other images showing probe geometry or equipment used for detection.

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Deliverables Response Table – Fill in the table below for each flaw type (1-8). Use “-“ if a capability is not applicable.

Flaw Type (See List Below)

Min Tube ID

(IN)

Max Tube ID

(IN)

Min Wall (MIL) Surface-

Roughness Range (min RA)

Type of Flaw

1 Circumferential Volumetric

2 Axial Volumetric

3 Circumferential Crack

4 Axial Crack

5 Voids

6 Delamination

Web - 1

Web - 2

Wall Thicknes s

Hot Flow Path

Cold Flow Path

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7 Tube Degradation

8 Wall Thickness

Please answer questions 1-12 from the “Technical Questions for Vendor” section here:

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