Coastal Inspection Services personnel meet the qualification requirements set forth by the National Board of Boiler and Pressure Vessel Inspectors and the VHA Directive 2008-062.

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Some of the methods we most often utilize:

  • Visual Inspection

Visual inspection is often overlooked in the application of most NDT methods, but as simple as this method appears to be, it is often the most abused. Nondestructive testing sometimes focuses on the technology to be applied to the area of interest without considering the need for assurance that the object is free of obvious discontinuities that can be revealed through visual inspection.

The use of weld contour gages and a good light source capable of generating over 100 foot candles of white light can often be used in the initial inspection of many structures, and pressure vessels. It is this initial inspection that often indicates suspect areas where additional testing may be warranted. This is very often the case in the internal inspection of pressure vessels. It is imperative that the inspector be tested to determine both near vision acuity and ability to contrast colors. The vision requirements are stipulated in most instances by the code or authorized inspection authority.

  • Liquid Penetrant Inspection

Liquid penetrant inspection is a method that is used to reveal surface breaking flaws by bleedout of a colored or fluorescent dye from the flaw.  The technique is based on the ability of a liquid to be drawn into a "clean" surface breaking flaw by capillary action

After a period of time called the "dwell," excess surface penetrant is removed and a developer applied. This acts as a blotter.  It draws the penetrant from the flaw to reveal its presence.  Colored (contrast) penetrants require good white light while fluorescent penetrants need to be used in darkened conditions with an ultraviolet "black light".

  • Magnetic Particle Inspection

MPI uses magnetic fields and small magnetic particles (i.e. iron filings) to detect flaws in components. The only requirement from an inspectability standpoint is that the component being inspected must be made of a ferromagnetic material such as iron, nickel, cobalt, or some of their alloys. Ferromagnetic materials are materials that can be magnetized to a level that will allow the inspection to be effective.

The method is used to inspect a variety of product forms including castings, forgings, and weldments. Many different industries use magnetic particle inspection for determining a component's fitness-for-use. Some examples of industries that use magnetic particle inspection are the structural steel, automotive, petrochemical, power generation, and aerospace industries. Underwater inspection is another area where magnetic particle inspection may be used to test items such as offshore structures and underwater pipelines

  • Ultrasonic Wall Thickness and Weld Inspection

Ultrasonic Testing (UT) uses high frequency sound energy to conduct examinations and make measurements. Ultrasonic inspection can be used for flaw detection/evaluation, dimensional measurements, material characterization, and more. To illustrate the general inspection principle, a typical pulse/echo inspection configuration as illustrated below will be used.

A typical UT inspection system consists of several functional units, such as the pulser/receiver, transducer, and display devices. A pulser/receiver is an electronic device that can produce high voltage electrical pulses. Driven by the pulser, the transducer generates high frequency ultrasonic energy. The sound energy is introduced and propagates through the materials in the form of waves. When there is a discontinuity (such as a crack) in the wave path, part of the energy will be reflected back from the flaw surface. The reflected wave signal is transformed into an electrical signal by the transducer and is displayed on a screen. In the applet below, the reflected signal strength is displayed versus the time from signal generation to when a echo was received. Signal travel time can be directly related to the distance that the signal traveled. From the signal, information about the reflector location, size, orientation and other features can sometimes be gained.

  • Remote Field Eddy Current

Eddy current testing for external defects in tubes where external access is not possible (e.g. boiler generating tubes), is conducted using internal probes.  

The difficulties encountered in the internal testing of ferromagnetic tubes can be greatly alleviated with the use of the remote field eddy current method.  This method provides measurable through penetration of the walls at three times the maximum frequency possible with the conventional direct field method. This technique was introduced by Schmidt in 1958. Although it has been used by the petroleum industry for detecting corrosion in their installations since the early 1960s, it has only recently evoked general interest. This interest is largely because the method is highly sensitive to variations in wall thickness, but relatively insensitive to fill-factor changes. The method has the added advantage of allowing equal sensitivities of detection at both the inner and outer surfaces of a ferromagnetic tube. It cannot, however, differentiate between signals from these respective surfaces.

All Nondestructive Testing that is performed is in full compliance with American Society of Nondestructive Testing [ASNT-TC-1A ].

ASNT Level III technicians review all test data from each project.

We always select the Nondestructive Test Method that can yield the most relevant information about the condition of a Boiler or Pressure Vessel.