Operating equipment downtime and faulty components mean lost production and lost revenue. Our Nondestructive Examination technicians travel across the country to provide observation and inspection services to help keep your project on track.

FST&R’s NDE services include Ultrasonic Testing(UT), Visual Testing(VT), Helium Leakage Detection, Liquid Penetrant Testing(PT), Radiography Testing(RT), Industrial Computerized Tomography (IND-CT),Infrared/Thermography Testing, Magnetic Particle Testing (MT).

Expedited NDE Services Are Available- 4006411668

Our field & laboratory services

Ultrasonic inspection conventional shear wave, PAUT, TOFD

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.

Phased Array Ultrasonic Testing (PAUT) is an advanced nondestructive examination technique that utilizes a set of ultrasonic testing (UT) probes made up of numerous small elements, each of which is pulsed individually with computer-calculated timing. This technique can be used to inspect more complex geometries that are difficult and much slower to inspect with single probes. PAUT can be used to inspect almost any material where traditional UT methods have been utilized, and is often used for weld inspections and crack detection.

Compared to other forms of UT, PAUT has several advantages. PAUT can be conducted more quickly than other forms of UT, often within a fraction of a second. It can easily be used for repeat scans because it has a high degree of repeatability. By emitting beams of multiple different angles sequentially, PAUT is able to create detailed and accurate cross-sections of a part. It is also particularly useful in situations where there is less room for mechanical scanning because it’s able to sweep the beam without moving the probe.

Time-of-Flight Diffraction (TOFD) is usually performed using longitudinal waves as the primary detection method. Ultrasonic sensors are placed on each side of the weld. One sensor sends the ultrasonic beam into the material and the other sensor receives reflected and diffracted ultrasound from anomalies and geometric reflectors. TOFD provides a wide area of coverage with a single beam by exploiting ultrasonic beam spread theory inside the wedge and the inspected material. When the beam comes in contact with the tip of a flaw, or crack, diffracted energy is cast in all directions. Measuring the time of flight of the diffracted beams enables accurate and reliable flaw detection and sizing, even if the crack is off-oriented to the intial beam direction. During typical TOFD inspections, A-scans are collected and used to create B-scan (side view) images of the weld. Analysis is done on the acquisition unit or in post-analysis software, positioning cursors to measure the length and through-wall height of flaws.

Visual Testing

Visual Testing (VT) is the most commonly used test method in industry. Because most test methods require that the operator look at the surface of the part being inspected, visual inspection is inherent in most of the other test methods. As the name implies, VT involves the visual observation of the surface of a test object to evaluate the presence of surface discontinuities. VT inspections may be by Direct Viewing, using line-of sight vision, or may be enhanced with the use of optical instruments such as magnifying glasses, mirrors, boroscopes, charge-coupled devices (CCDs) and computer-assisted viewing systems (Remote Viewing). Corrosion, misalignment of parts, physical damage and cracks are just some of the discontinuities that may be detected by visual examinations.

Helium Leak Detection

Helium is the best choice of tracer gas to find leaks for a number of reasons.   It is non-toxic, inert, non-condensable, non-flammable and not normally present in the atmosphere at more than trace amounts (5 ppm).   Due to its small atomic size, helium passes easily through leaks.   The only molecule smaller than Helium is Hydrogen which is not inert.   It is also relatively inexpensive and is available in various size cylinders.

Helium Leak Detection

A helium leak detector, also known as a Mass Spectrometer Leak Detector (MSLD), is used to locate and measure the size of leaks into or out of a system or containing device.   The tracer gas, helium, is introduced to a test part that is connected to the leak detector.   The helium leaking through the test part enters through the system and this partial pressure is measured and the results are displayed on a meter.

Helium leak detectors consists of the following components:

•A spectrometer to detect the mass of helium

•A vacuum system to maintain the pressure in the spectrometer

•A mechanical pump to evacuate the part to be tested

•Valves which enable the various stages of detection: evacuation, test & venting

•An amplifier and readout instrumentation to monitor the output signal

•Power supplies and controls

•Fixturing that attaches the part to be tested to the detector

Methods of Leak Testing Parts

There are two main methods to leak test parts using helium: vacuum testing (outside-in) and pressure testing (Inside-out).   The detection method should be selected based on the working conditions of the part to be tested.   It is important to maintain the same pressure conditions during the test as will exist during the actual use of the part.   Vacuum systems should be tested with a vacuum inside the chamber.   A compressed air cylinder should be tested with high pressure inside the cylinder.

Vacuum Testing (Outside-in)

In vacuum testing, the part is evacuated with a separate pumping system for larger volumes, or within the detector itself for smaller volumes.    To locate a leak, helium is administered to the suspected leak sites of the part using a spray probe with an adjustable flow.

Pressure Testing (Inside-out)

In pressure testing, the part is pressurized with helium or a mixture of helium and air. To locate a leak, the potential leak sites of the part are scanned using a sniffer probe connected to the inlet of the leak detector.

Leak Testing Vacuum Systems & Pressure Systems

Vacuum systems and pressure systems should be leak tested under the same conditions as their operational conditions.   Vacuum systems are tested with a portable leak detector.   The leak detector is connected to the line of the vacuum pump.   Helium is applied to the the potential leak site using a spray probe.   If a leak exists, helium enters the system and quickly diffuses through it.   The leak detector should respond within seconds. Pressure systems can be charged with helium or a mixture of helium and nitrogen.   The leak testing is performed by using a Sniffer probe.

Helium Leak Detection Applications

Quality control of production parts and assemblies using helium leak detectors can help assure the integrity of your production process.   Typical examples include: hermetically sealed packages, valves, manifolding, seals, vacuum vessels and systems, medical devices, high purity piping, brake lines, fuel lines, hydraulic lines, refrigeration assemblies, radiators, heat exchangers, condensers, storage tanks.

Maintenance of Systems

Industrial process tools that use vacuum systems or pressure systems must be tested to check for occasional leaks.   This can be part of preventative maintenance   or in the event of an unexpected failure.   Typical examples of vacuum systems include: Vacuum furnaces, vacuum coaters, electron microscopes, glove boxes, linear accelerators, electron beam and ion beam process equipment, semiconductor process equipment, laser process equipment.   Typical examples of pressurized systems include: power plants, gas handling systems, bioreactors, liquid gas facilities, underground tanks, underground cables and pipes.

In FST&R, we can also perform the following NDE and field inspection,

Expedited NDE Services & Field Inspection Services Are Available- 4006411668

• Liquid penetrant inspection (PT)

• Radiography (iridium, cobalt, and X-ray)

• Industrial computerized tomography (IND-CT)

• Infrared/thermography testing

• Magnetic particle inspection (MT)

• Positive materials identification (PMI)

• Field metallography

• Field hardness inspection

• Welder qualifications (WQT)

• Welding procedure qualification record (WPQR)

• Welding procedure consulting services

• Level III consulting services

• Mechanical testing and analysis