The system consists of floor mounted sump supporting a 20ft (8m) long SDI-1334 heavy duty rotator. The transducer(s) are mounted in-line in a high flow irrigated housing which rides in contact with the bar.
This type of housing is used extensively on the SDI compressed gas cylinder inspection systems which are used with very heavy duty cycles on a variety of rough surfaces. It provides coupling equivalent to an immersion system as a water filled chamber is maintained between the transducer and the part.
The test head is mounted on a cantilever bridge equipped with a bar follower assembly. There are a number of different contoured shoes which can be rapidly changed by the operator to accommodate different bar diameters. Each shoe size will test several different bar diameters.
The bar to be tested is loaded onto the rollers while the transducer/follower assembly is parked in a housing at either end of the scanner. As the bar is rotated, the transducer assembly traverses the entire length of the bar.
All test parameters, including rotator speed, helix pitch etc are controlled by the SDI-1830-UTB system controller. The time to test a bar is dependent on the test standard defect size and determined by the bar diameter. To reduce inspection time the testing is performed bi-directionally.
The test bridge moves off the bar into a shielded housing at the end of each scan. It remains protected until the next bar is loaded onto the rotator then it emerges and travels the opposite direction down the length of the next bar and into housing the other end. The sequence is repeated for each bar.
The modular design allows rapid reconfiguration of the system to accommodate different lengths and diameters of bar. The detailed description of the modules is given below.
The test station is the main operating station of the system and contains the sump, rotator, bridge and system controls. In the majority of systems, the instrumentation and system controls are housed at the end of the test station, as this is where the operator will usually be located.
The test station frame is fabricated from welded steel and finished with epoxy paint. The overall length is 30ft. and the depth 3ft. The SDI-1334 rotator will function in either direction with continuously variable speed. The maximum speed is 40 surface in per sec.
A number of auxiliary modules are available for improving the inspection efficiency.
Automatic defect markers are available for indelibly marking the product downstream of the test station. Both paint jet and felt tip markers are available.
A computer-based defect logging package is available for producing a tabular output of defect location and material length.
Water Conditioning Unit
A recirculation pump and filter system ensures water quality is maintained under normal working conditions. Optional temperature control and de-airation units can be provided.