ABOUT NDT TEXAS NDT Texas LLC is an ISOFLEX USA company based in Houston, TX. We are pleased to serve the needs of the nondestructive testing (NDT) industry by providing an extensive line of high-quality equipment, accessories and services, primarily in the following areas: Radioactive Sources Radiographic Testing (RT) Ultrasonic Testing (UT) Liquid Penetrant Testing (PT) Magnetic Particle Testing (MT)