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IRISPIG: - IRISPig Inc. Dl. IRISPIG: A new ultrasonic pig for inspection of short, small diameter lines, ie flow lines, production lines and other non-piggable pipes. Instrument consists of self contained modules housing power supply and electronics data acquisition module.
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IRISPIG: - IRISPig Inc. Dl • IRISPIG: • A new ultrasonic pig for inspection of short, small diameter lines, ie flow lines, production lines and other non-piggable pipes. • Instrument consists of self contained modules housing power supply and electronics data acquisition module. • Technique uses a single immersion transducer and a rotating mirror head • Inspection pig is launched into cleaned pipe along with a couplant reservoir • Unit is pushed using water at up to 5 m/minute. The mirror rotates sending ultrasonic signals to the pipe wall. Electronic unit measures "time of flight" between front and back wall signals. This pig data includes tube diameter remaining wall thickness and indicates defects. • Electronics acquires 180 readings per 6mm wide sweep revolution. • IRISPig negotiates 1.5 D bends and can inspect up to 5 km pipelines.
Current maximum diameter for inspection is 400mm. • Data writes directly to hard drive and is downloaded on retrieval. • Data is given in a color coded "C-Scan" or "B-Scan" Windows format. IRISPIG is made to test pipelines that have not been able to be inspected or have been un-economical to inspect by traditional inspection methods. There are other similar systems but they are supported by umbilical cables and have to be winched through the pipe. • IRISPIG is self contained reversible unit to run up to 5km in length. • On retrieval downloaded data is available within 20 minutes . • Data is downloaded to computer hard-drive and can be written on to CDR and viewed in Windows program
IRISPIG.Unit assembly: • The IRISPIG consists of three separate assemblies joined with universal couplings. There is a push/pull unit, a power unit and the inspection unit. • IRIS UNIT POWER PUSH / PULL • ◄============2.05m==============►
Description of Operation. Ultrasonics . • An ultrasonic signal is reflected through a rotating 45 mirror into the wall of the pipe. Return echoes from the front and back walls of the pipe give the pipe diameter and wall thickness. The scan width of each rotation is 6mm. Each scan paints a circumferencial profile of the Inside and outside wall of the pipe.
Method of Inspection. • Using this technique, the inspections are performed on ‘out of service’ lines. • After the client has suitably cleaned and prepared the line for inspection, a batch pig is launched with water down into the line. • Distance the batch pig is pushed down the line depends on length of line to be tested. This water reservoir is the couplant tank for the UT inspection. Pressure is maintained on sealine to hold batch pig while water is being used to push in.
Next the IRISPIG is launched into the pipe. It has a delay timer set so that the unit is not collecting data while lying idle in the launcher. The pig is launched, the valve to the pipe is opened and residual air in the couplant reservoir is bled off. The system is sealed and the pig is pushed with water along the length of line to be inspected. • IRISPIG is launched, air bled from system and batch pig, water couplant and IRISPIG are pushed with water. Slight Forward pressure is maintained on the sea-line to stop batch pig runaway
If the line is accessible from the other end, the pig can be moved to that end for removal, however if it is a single access line, then after the desired length of inspection, Reverse pressure is applied to the pig train and it is backed out of the pipe to the launcher/receiver. After removal, pig is decontaminated/cleaned and data downloaded to a laptop computer. • Results. • Results are viewed in a Windows program. A condensed C scan image of the inspected area is presented.
Pig being decontaminated • Condensate and mercury deposits adhering to the pig.
Unit has an auto advance data writer as well as a distance encoder overlay on the data presentation.. • Screen data image of test from a 14inch diameter riser and section of sea-line. This shows full length scan, zoom area and the B scan for one selected sweep
Tube Length Profile The inspected section of sea-line was 465m long. Using Viewer program software, the pipe image is broken into smaller 3m sections. The inspector can then “walk” along these sections 6mm at a time, looking at the B scan thickness presentation. i.e. The inspector opens up the condensed image into 3m sections and can scan along these B scan frame by frame, looking at the ID & OD wall. On screen measure cursors give immediate thickness readings in addition to the color thickness range codes.
B Scan image of one sweep of the turbine around pipe circumference Good section of pipe Min 15.4mm
B Scan image of one sweep of the turbine around pipe circumference Internal corrosion in pipe 12.1mm Nominal 16.3mm
Developements • IRISPig 6-12” • Tethered inspections have been done with the IRIS technique on pipes up to 12 inches in diameter for 6 years. Because the IRISPig works well, we are reducing the its size to fit 6 – 12 inch pipes. It will be able to operate as either a tethered unit with real time scan or a stand alone unit to be sealed into a pipe and pushed through the same as the larger version.
Conclusion • With newregulations on pipe inspection coming into force each day, and with the climbing costs or pipe replacement & repair, customers are anxious to know the condition of un-inspected piping. Examples of this piping is offshore risers on wells and platforms, short flow lines around refineries and tank farms, road , rail and river crossings to name a few. Sometimes existing inspection equipment is just unpractical to be used to do these inspections. • IRISPIG is a new instrument to assist in this work. It is lightweight, easily transportable and provides swift readable and repeatable data to the customer.