Materials Handling & Accessories

MECHANICS FOR MOUNTING TEST SENSORS

Proper positioning of the eddy current test coil with respect to the material being tested is a key ingredient of any eddy current inspection system. MAC Coil Platforms can be adjusted vertically and horizontally to provide proper alignment with the material to be tested. Encircling (throughput) or tangent (sector) test coils can be accomodated.MAC has a range of coil platforms that support eddy current encircling and sector test coils designed for various applications, including cylindrical and shaped material, and magnetic and non-magnetic material. These platforms can handle test material sizes up to 235 mm (9.25″) diameter for encircling test coils and up to 304.8 mm (12.0″) diameter for sector (tangent) coils.

PDF File: Coil Platforms

Standard Coil Platforms are designed for the inspection of non magnetic material.

Coil Platforms for Testing Magnetic Material

Specially designed DC Coil Platforms incorporate a direct current encircling saturation coil which is necessary for testing most magnetic material. By adequately saturating the test material, accurate test results can be obtained.In most cases, DC Coil Platforms for encircling test coils require a continuous supply of water for cooling. Tangent Coil Platforms, however, do not require water. Contact MAC for specific water and power requirements for Coil Platforms.

When using spinning eddy current probe or magnetic flux leakage inspection equipment, a Rotary Mechanism which incorporates the eddy current probe coils in a housing designed to spin the probes around the material, is used instead of a standard encircling or segment coil. The Rotary Mechanism may be adjusted for proper elevation and horizontal position, similar to Coil Platforms.Where rotating eddy current probes are being used, they are housed in a rotary headplate, mounted in rotary mechanics that include a motor for spinning the headplate with its test probes around the material under test. Current rotaries feature continuously variable high speed rotaries (1800 – 6000 RPM), capable of handling test material up to 191 mm (7-1/2″) diameter.

PDF File: Rotary Mechanics for Eddy Current Systems

MAC’s Echomac® UT Rotary rotates ultrasonic transducers for shear-wave and compression-wave configuration at high throughput speeds. Standard models handle material from 6.3 mm to 220 mm (1/4″ to 9″) at test speeds up to 400 fpm, depending on the size and condition of the test material.

Flux leakage test systems incorporate rotating test probes, mounted in a rotary headplate assembly. Current systems are available to handle up to 406 mm (16″) diameter and 19 mm (3/4″) wall thickness. Picture shows the headplate with test probe assemblies and magnetizing pole pieces for detecting longitudinal defects. Rotary mechanisms designed for detecting transverse defects are also available.

PDF File: Rotary Mechanics for Ultrasonic Systems 

TEST BENCHES & DRIVES

The various coil platforms and rotary mechanics described above can be mounted on a MAC test bench which aligns the test material with the test sensors. MAC’s standard test bench utilizes 120 degree “V” rolls and pinch stands to support and position the test material. The fixed bottom “V” rolls, in conjunction with a flat top roll, provide 3 points of contact and ensure firm support for the test material, eliminating vibration that can cause false indications. Automated or manual controls adjust the pinch stand rolls to the size of the test material. Drive Mechanisms provide forward movement of the test material through the coil platforms and rotary mechanics where needed. Individual elevating platforms are usually included on the test bench for positioning larger rotary mechanics. 90 degree rolls are also available for square material. Auto diameter controls are available to automate adjustments of the testers and drives when the test material diameter is changed.

Automated or manual Pinch Stands help eliminate vibration that can interfere with the test, and ensure that the test material is properly positioned as it enters and leaves the test sensors. Pinch stands can be mounted on a test bench, or directly on a production line.

MAC’s subsidiary M A Nordic offers a constant center, automated triple drive and table to accommodate several testing systems, including stationary or rotary eddy current, flux leakage, or ultrasonic instruments. A constant center triple drive roll bench is another option for mounting the various mechanical components for MAC test systems. The bench eliminates vibrations from the test material that can cause false reject signals. A triple pinch is mounted between each test station on the bench. Each pinch, driven by a separate AC motor, uses three hardened steel rolls to center the test material. A frequency converter controls the AC motors to guarantee equal speed for all of the pinches. Slide mechanisms are available to allow access to test heads for off line setup and maintenance.A single point adjustment of the table and diameter of the triple driving and centering guide aligns the table and testers with the production line. It is especially applicable to products such as tubes with badly formed ends, upset pipe or difficult straightening applications.

FEED SYSTEMS

The Feed System’s modular design permits quick assembly into many configurations to handle various lengths of material, and allows for later additions or changes. Both round and hexagonal material can be accommodated. Models are available for handling bars or tubing ranging in size from 1/8″ (3.18mm) up to 7-1/2″ (191mm).At right is a view of a MAC Feed System with a feed table and receiving pocket. Below right are receiving pockets with “easy down” belt feature to prevent bars from hitting the bottom.

Typical Application:

• Automated feeding, rejecting and handling of bars and tube in ndt test stations.

PDF File: FEED SYSTEMS.pdf For Use With: Bars and Rods, Tubing