03:33 Jun-21-2001 Richard D. Roberts Engineering, Executive Managment Quest Integrity Group, USA, Joined Nov 1998 78
Re: NDT on Ethylene Pyrolysis furnace tubes
QUEST Integrated, Inc. had developed a "teatherless" (remote) inspection tool, which employs the combined capabilities of high-speed laser and advanced ultrasonic wall thickness measurements. This tool is transported through the piping via a column of clean water, which provides propulsion, a path for the laser beam, and coupling for the ultrasonic signals. The data is processed and stored in the tool using high-speed digital signal processing modules. At the conclusion of an inspection run, the operator downloads the data from the tool to a portable data station. Features such as internal pitting, corrosion, erosion, swelling, and deformation are located and quantitatively mapped. Custom software provides the ability to view the data with contour, cross-sectional, and tabular displays. The furnace tube inspection service (FTIS) is expected to significantly improve both the quality of inspection data and overall safety in the operation of refinery furnaces.
The Furnace Tube Inspection System (FTIS) is a hybrid-technology tool for the inspection furnaces containing 4- to 6- inch (10- to 15-cm) tubing.
The FTIS simultaneously measures: a) Inside radius b) Average radius c) Pit depth d) Wall thickness e) Average wall thickness f) Axial position for all defects.
Advantages Include: a) Performs noncontact in situ measurements, b) Survives harsh hydraulic inspection environments, c) Inspects entire furnace in 15 minutes or less, d) Negotiates one-dimensional (1D) return bends .
You can visit the QUEST web-site at http://www.qi2.com/field/fsddef.htm for additional information or contact me directly.
Regards, Rich Roberts --------------- ORIGIONAL MESSAGE ----------- : What are the most common NDT methods used to inspect the condition of the tubes? What are the limitations? . : Thank you. .
01:09 Jun-30-2001 John O'Brien Consultant, - Chevron ETC , USA, Joined Jan 2000 278
Re: NDT on Ethylene Pyrolysis furnace tubes A number of Ethylene Plants apply Acoustic Emission during a hydrotest of the tubes. Activity in the AE occurs from early stages of damage (ie Before the level of ultrasonic detection). Results grade the level of activity in the tubes and they can then be prioritised for other more time consuming inspections such as the Laser, Ultrasonics etc. Good success is reported in A) the speed of the test as all tubes can be tested in one shot B) the ability to identify early stages of damage C) prioritisation and risk ranking for replacement or other inspection work.