Posts

Showing posts from March, 2021

MAGNETIC PARTICLE TESTING EQUIPMENT

Image
 The following should be considered when selecting equipment for magnetic particle testing. Is equipment for wet or dry method? Magnetization requirements (AC or DC) Demagnetization- incorporated or separate unit? Ampere required. Line voltage requirements. Accessories needed or required. WET HORIZONTAL EQUIPMENT To obtain circular magnetization , the specimen is clamped between the head and tail stocks . For longitudinal magnetization the coil is moved so that the area to be tested is encircled by the coil . A typical wet horizontal unit usually accommodates both AC sand HWDC magnetization . The wet continuous-field method has three basic steps: Flow bath through nozzle and over entire surface of part. Stop bath flow. Apply current at the instant bath flow is stopped. Dry continuous-field method With this method the powder is usually applied from a shaker, bulb, or Blower and follows these steps: Apply magnetizing current. Blow powder particles

Standards for Piping Design and Inspection

Image
  Standards for Piping Design and Inspection: The original ASME B31 Code for Pressure Piping was first introduced in 1935 as the single document for piping design. In 1955, ASME began to separate the code into sections to address requirements of specific piping systems, as follows. B31.1: Power Piping is for piping associated with power plants and district heating systems as well as geothermal heating systems. Its main concern is the steam-water loop in conventionally powered plants. More recently, it has added a chapter to require maintenance plans for the plants that produce the power. B31.2: Fuel Gas Piping Code was withdrawn in 1988, and responsibility for that piping was assumed by ANSI Z223.1. It was a good design document, and although it has been withdrawn, ASME makes it available as a reference. B31.3: Process Piping (previously called the Chemical Plant and Petroleum Refinery Piping Code) is the code that covers more varieties of piping sy

ISO Standards for Ultrasonic Testing

Image
  Ultrasonic Testing In Ultrasonic Testing we use something called “Ultrasonic Vibrations” we must know two facts about a vibration: A vibration is a back and forth movement. A vibration is energy in motion A depression of a surface from its normal position is called a displacement. Vibrations pass through a solid material as a succession of particle displacements; this can be visualized as shown below: The structure of a material is actually many small particles or groups of atoms. These particles have normal or rest positions and can be displaced from these positions by some force, when the force is removed, the particles will tend to return to their original positions. Energy is transmitted through a solid material by a serious of small material displacements within the material. The transmission of Ultrasonic vibrations through a material is related to the elastic properties of the material. In Ultrasonic Testing a transducer made of Piezo-electric crystals is used

Sensitivity setting for ultrasonic testing as per ISO 17640

Image
  Range and Sensitivity Setting  for Ultrasonic testing Setting of range and sensitivity shall be carried out prior to each testing in according to this procedure. The temperature difference between the time of range and sensitivity setting and time of test should be within ± 15°C. Checks to confirm these settings shall be performed at least 44 hour once and on completion of tests. The checks should also be done whenever a system parameter is changed. If deviations are found during these checks , corrections given in the below Table. 1 shall be carried out. Reference for Sensitivity Setting for Ultrasonic Testing One of the following technique shall be used for setting of reference Technique 1:  The reference is a Distance Amplitude Curve (DAC) from a dia 3mm side drilled hole. Technique 2:  The references for transverse and longitudinal waves using the distance gain size technique (DGS) based on the diameter of the disk shaped reflector (DSR) are given in the table 2 & Table 3.