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NDT International, Inc. has developed a magnetic wheeled crawler inspection
system that offers a complete, portable AC or DC powered, inspection vehicle usable for
ultrasonic thickness measurement of steel storage tanks, piping and other steel
structures. It has been adapted for other similar applications where inspection is
not easily accessible by normal methods. The steerable crawler vehicle is powered by
two 12 VDC high torque gear motors and carries a center mounted spring-loaded ultrasonic
transducer and water line.

The operator can make a nearly
continuous scan from top to bottom of a tank from the ground. Information gathered
in this manner can be used to determine the probability of corrosion and pitting in an
entire vessel. Our system is comprised of the MARK IV-B crawler vehicle, the
spring-loaded dual element crawler transducer with integral water line, 100 ft. long cable
assembly and our Crawler Control Module that accepts both AC and DC input power..
System Includes:
MARK IV-B Crawler Vehicle with two 12 VDC motors (rated as explosion
proof per MIL-M-8609 and MIL-E-5272), high strength magnetic wheels and an electrical
connector panel. Overall physical dimensions of the vehicle are 12" L x 6"
W x 6" H.; Vehicle Weight is 8 lbs.
Vehicle speed range is from 1 to 30 feet per minute when on AC power. Speed will
vary when using an external DC power source. Scanning results are best when the
vehicle moves at slower speed. Vehicle holding force is up to 50 lbs. per wheel
depending on surface conditions and paint coating thickness that will greatly impact the
holding force of the vehicle.
Crawler Transducer is a 1/2" diameter x 5 MHz high Gain
spring-loaded dual transducer with an integral water tube for couplant application.
It is compatible with nearly any ultrasonic flaw detector and many high-end thickness
gauges.
Cable Assembly standard length is 100 feet and includes Power line, Dual
Transducer line and a 1/8" ID PVC Couplant/Water line in a braided plastic sheath to
prevent tangles.
Power/Control Unit 110 VAC or 12 VDC Power Input. Has Left/Right,
Forward/Reverse and Power Level Motor Controls.
Spare Parts Kit (for minimum of two year operation): Includes (2) gear
motors, (1) transducer, (1) complete wheel assembly with axles & gears, (2) stainless
steel drive chains, all misc. tubing fittings and electrical connectors
System is available without the UT Instrument, Computer and Software
OPTIONAL Single large Fiberglass Transport Case or pair of smaller cases.
We currently have one large single case is in stock. 40"L x 34"W x
20"H, black composite ABS, hinged cover, four handles, two latches, with six foam
lined compartments.
Warranty: One year from date of shipment parts & labor on
primary components
Thirty days on motors, transducers, cables and batteries
Lead Time: Currently 4 to 6 weeks, F.O.B. West Chester, PA - All
shipping charges are extra.
Terms of Payment: 50% within 10 days of order. Work will not commence
until prepayment is received. Net Balance due prior to shipment.
Frequently Asked Questions:
Minimum and Maximum Range of Measurement?
Absolute minimum range using the 5.0 MHz transducer is about 0.060" (1.5mm) to
maximum of 6.000" (150.0mm).
Prerequisites required for the thickness measurement?
Operator should be well trained in ultrasonic theory and applications.
Vessel being inspected should be clean with no flaking paint or rust.
Accuracy of the results?
Typical accuracy depends upon thickness.
Under 1.00" Thick +/- 0.003" Over 1.00" Thick +/- 1% of wall.
Crawler vehicle weight is approx. 8 lbs.
Approximate shipping weight for the complete system with transit case is 200 lbs
Equipment guarantee?
One year warranty on instrumentation parts & labor.
Thirty days on motors, transducer, cables & batteries.
If a system is ordered, how will you deliver it to our
location?
Foreign shipment via TNT Global Express (Air) or your specified carrier.
Domestic shipment by UPS Ground Service.
MARK I Lightweight Crawler Vehicle
If you need something easy to use and inexpensive consider our MARK I Crawler
vehicle. This is a 3-wheeled vehicle that has been designed to be manipulated
(raised and lowered) by hand using an extension pole with pulley system (not supplied by
NDT) or just a rope with a top-side assistant. The same High Gain 1/2" diameter, 5 MHz
spring-loaded dual transducer as the motor driven MARK IV-B is included. It
can be attached to many different ultrasonic testing instrument as long as they can drive
a signal through the 50 foot long cable.
The Mark I Crawler Vehicle measures only 8
1/2" L x 6" W x 4 1/2" H. It includes a plastic Shim Set for
adjusting the clearance of the magnets attached to the underside of the nylon
chassis. These magnets provide a holding force of 8 lbs. @ 1/8" clearance from
the steel surface. Also included is a 50 foot long Transducer and Couplant Line
Cable Assembly and a hand pumped, 2 gallon capacity Couplant Supply Tank. Weight of
the Crawler is 2 1/2 lbs. with transducer.
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