This document summarizes a team project to design a device to help center radioactive sources inside pipes during inspections. The team includes Joshua Terry, Nate Elledge, Manny Alvarez, and Richard Crabb. They provide an outline, introduction, problem statement, objectives, functional requirements, constraints, and engineering design specifications. Three potential design concepts are presented: a ratcheting lever arm device, a telescoping two-pole device, and a crank-driven locking centering device. The concepts are evaluated against selection criteria such as tolerance, reliability, cost, weight, bulk, and maintenance. Concept 2 is selected for further analysis and refinement because it provides the most accurate centering and has sufficient function at a portable

1. Team Members
Joshua Terry, Nate Elledge,
Manny Alvarez, Richard Crabb

2. Joshua
Outline, Intro, Design Concept Process Initial
Stage(Problem, Objective, Function
requirements, Constraints, EDS)
reference ETS 2-18

3. Outline
Introduction
Problem Statement
Objectives
Functional requirements
Constraints
Engineering Design Specifications
Design Considerations
Potential Design Solution
Design Evaluation
Product adaptation?
Project Timeline

4. Introduction
Pipes commonly welded together require x-
ray type inspections of the welds
Technicians climb inside pipes and setup a
radioactive source
inspectors make their own 'garage shop'

5. Problem Statement:
● ACE'T strives to simplify the process of radiographic inspections of welds in pipes.
● must place a radioactive source in the exact center of a pipe during each inspection.
● no standardized apparatus to help with this.
○ Varying levels of the radiation exposure
○ inconsistent position of the source
○ work stoppages
○ need for re-testing

6. Objectives
● improve the accuracy of NDT pipe inspections
○ simple hand-held mechanism ACE’T will design
○ center the source inside the pipe

7. Objectives
● lower exposure rates to the highly radioactive sources used in this type of testing
○ expedite the inspection process with standardized equipment

8. functional requirements
● Accuracy
The system must be able to center itself inside a pipe within 5% of the true radius of the pipe.
● Portable and Lightweight
The mechanism should be easy to transport to and from a jobsite. Not bulky or too heavy to use during inspections
inside pipes.
● Reliable and Rugged
It should be designed with a level of tolerance to misuse and rough handling that occurs in the field.
● Adjustable
A wide variety of pipe sizes are common in this industry

9. Functional requirements
● Locking
The device shall be able to be locked into position once installed.
● Ease of use
The mechanism should be simple to operate by inexperienced personnel
● Self Supporting
The system shall be able to support itself once attached to the walls of the pipe and be able to withstand a
slight perturbation without falling down

10. Constraints
● Should be less than 25 pounds
● Should not require electrical power to actuate

11. Engineering Design
Specifications
Operatizing environment
● Dusty environment with dirt, grime, and moisture (outdoors)
● No failures should occur during economic lifetime of the part
● Device should accommodate variations in temperature, pipe wall texture, pipe diameter, and user frame size

12. engineering design
specifications
Economic
● Should have economic life of more than 5 years
● Should not require routine maintenance other than cleaning and possible lubrication
Geometric limitations
● Compact size capable of folding or collapsing into portable shape
● Total length of less than 3 feet when collapsed
● It should accommodate this size of pipes frequently inspected by NDT (36-60 in diameter)
Maintenance, repair, retirement
● Should be easy to clean and require no disassembly to do so
● No repairs should be required during economic life
● No special disposal or considerations required
Reliability, robustness

13. engineering design
specifications
Pollution
● Will not create hazardous waste in landfill or recycling center when disposed of
Ease of use
● Simple, self explanatory operation
● Simple to remove parts to replace damaged or worn components
Human factors
● No large forces or torques require to actuate or disengage
● Handholds and grips should fit 5-95th percentile females and males
● Obvious mode of operation
● Parts graspable and not slippery or loose

14. engineering design
specifications
Safety
● Will not pinch or snag or otherwise cause bodily harm during normal use
● Will not collapse or unlock unintentionally and fall onto operator
● The device will not have any sharp edges
Appearance
● Surface finish should be smooth to facility cleaning
Manufacturing
● A beta prototype should be ready in 8 months (by end of Senior Design)

15. Manny
Design Concept Process Final Stage(Design
Considerations, Concept Candidates):
reference ETS slides 15-25

16. Design Considerations
● Leg Types
○ Telescoping
○ Fixed Length
○ # of Legs
● Holding Force
○ Ratcheting
○ Friction
○ Gears

17. Design Considerations
● Storage
○ Folding
○ Nesting Parts
● Finding Center
○ Three-Point
Reference
○ User-Determined
With Graduated
Markings

18. Leg Design Considerations
● Primary
○ Strength
○ Reliability
○ Lightweight
● Secondary
○ Simplicity
○ Low Maintenance
○ Compact

19. Holding Force Considerations
● Primary
○ Engages and
Disengages on
Demand
○ Reliable for
Reasonable Length
of Time
● Secondary
○ Simplistic
○ Ease of Maintenance
○ Setup Speed

20. Storage Considerations
● Primary
○ Compact
● Secondary
○ Ease of Storage
○ Safety

21. Centering Considerations
● Primary
○ Accuracy
○ Precision
● Secondary
○ Centering Speed
○ Operating Ease

22. Design Solutions
1) Ratcheting 2) Telescoping 3) Crank
Lever Arm 2-Pole Driven
Centering Centering Locking
Device Device Centering
Device

23. Ratcheting Device Characteristics
● Tripod centers "Umbrella" design
through friction
between pipe and
feet
● Sliding collar on
body opens up legs
simultaneously
● Ratcheting on body
prevents unwanted
closing

24. Ratcheting Device Considerations
● Pros ● Cons
○ Easily opened and ○ Multiple articulating
closed joints/linkages
■ No tools needed ■ Deform in one
○ Rugged design part impacts
○ Can be placed in whole system
non-standard pipe
sizes

25. Telescoping Device Characteristics
● Central hub with "Shower Rod"
two telescoping
arms
● Graduated
markings help
operator find center
● Pins lock legs in
place at standard
pipe sizes
● Held up by friction

26. Telescoping Device Considerations
● Pros ● Cons
○ Ease of use ○ Susceptible to kinks,
○ Quick actuation bends or twisting
○ Lightweight ○ Only two points of
○ Compact contact
○ Only for standard
pipe sizes
○ Accuracy more
susceptible to user
error

27. Crank Device Characteristics
● 3 Folding arms lock
into place
● Arms telescope out
with turning of
crank
● Ratchet on crank
prevents collapse

28. Crank Device Considerations
● Pros ● Cons
○ Folds to compact ○ May be high
size maintenance
○ Very Stable ○ Susceptible to
○ Can be used in non- misalignment
standard pipe sizes ○ Heaviest
○ Slow actuation

29. N8
Evaluation, Project Timeline, FBD, Selected
Concept
reference ETS slides 26-32

30. Selection Criteria
with Weighting Considerations
● Tolerance: Capable of centering within 1 inch of a 36 inch pipe
● Reliability: Operates repetitively in an ideal environment for a
minimum of 10^3 cycles
● Low Cost: Able to be mass produced for under $1000
● Light Weight: As light as structurally possible with a max weight
< 25 lbs
● Bulk: Compact enough for portability in the smallest dia. pipe
intended (36 inch)
● Low Maintenance: Operates in the field 10 times without
performing maintenance (ex. oiling, cleaning, replacing wear
items)
● Simplicity: Experienced operator must be able to set up the
device within 5 minutes in a pipe lit only by portable lantern or
flashlight

32. Project Timeline
● October
○ Midterm Team Presentation
○ WP4
■ Cost
■ Scheduling
● November
○ October Monthly Status Report
○ WP5: Preliminary Design & Analysis
○ Final Poster
○ Final Report and PPT Drafts
● December
○ Final Presentation
○ November Monthly Status Report
○ Final Report

33. Elementary Physical Analysis
Concept 1 Concept 2 Concept 3
The FBD are in a PPT file in the WP3 folder.
It was the best way to create the diagrams.
Let me know if you have any problems.
Hopefully, you're using MS 2010.

34. Concept 2 Elementary Physical Analysis
The FBD are in a PPT file in the WP3 folder.
It was the best way to create the diagrams.
Let me know if you have any problems.
Hopefully, you're using MS 2010.

35. Concept 3 Elementary Physical Analysis
The FBD are in a PPT file in the WP3 folder.
It was the best way to create the diagrams.
Let me know if you have any problems.
Hopefully, you're using MS 2010.

36. Selected Concept
Functional Requirements Statements
● Strengths (Strong Proficiency in the following Selection
Criteria):
○ Tolerance: provides the most accurate means of
geometric centering
○ Weight: design has sufficient function at a portable
weight
○ Maintenance: physical characteristics create a
durable product
● Design Configuration Progression
○ Further analysis of component selection and
arrangement
○ Selection and arrangement of features
○ Refine alternative configuration
○ Model configurations

37. irrelevent questions
expected from Steven
what is the half life of the source?
what about plastic pipes?
what type of sources are used?
what if the technician is working two jobs?