QUALITY CONTROL

PROCESS

TIMET monitors all ingot and subsequent product forms through all steps of processing. It is our aim to supply each processing area with "defect-free" material. The ingot data chemistry is checked for conformance to specification. Slabs are then visually inspected for quality and shape (and conditioned as required) and all conversion steps to final hot-rolled strip are carefully monitored. Cold reduction to the gauge ordered is controlled by X-ray equipment. Very close dimensional tolerances are possible. Production operators and inspectors complete work sheets for each individual step of processing, checking for compliance to standard procedures and evaluating product quality. Skelp is finally slit to width and is carefully protected to prevent contamination prior to forming.

In-process tests are performed by tube mill weld line operators on a regular basis. These include tensile testing, flaring, flattening and reverse flattening as well as dimensional checks and weld inspection.

INSPECTION AND TESTING

TIMET performs the following non-destructive testing on 100% of the tubes manufactured.

EDDY CURRENT TESTING - Eddy current (electromagnetic) testing equipment is located in-line and is utilized subsequent to the welding process. Testing is in accordance with ASTM E-426. TIMET's calibration standard is a .031" diameter drilled hole per ASTM B-338. The system incorporates an automatic marking system which alarms, paints, and automatically cuts out the defect area. Tubes that pass eddy current testing are cut-to-length, deburred, then ultrasonically tested.

ULTRASONIC TESTING - Ultrasonic testing is carried out in accordance with ASTM E-213. The calibration standard is longitudinal ID and OD notches which are either 10% of the nominal wall thickness or .004", whichever is less.

Both the eddy current and ultrasonic testers are adjusted to reject a tube at 50% of the calibration tube signal.

PNEUMATIC TESTING- Pneumatic testing is performed after final inspection and immediately prior to boxing.

For tubing sized up to and including 1-1/2" O.D., the pressure differential technique is utilized. The differential pressure tester is designed to test titanium tubing by measuring the difference in pressure between two tubes. The test cycle is fully automatic, complete with leak diagnosis, alarming and automatic shutdown. A programmable controller makes the pass/fail determination for the tubes under test by comparing data input from the differential pressure transducers. A pressure loss in any tube greater than 0.04 PSI triggers an alarm. Standard test pressure is 110 PSI minimum for seven seconds.

For tubing sizes over 1-1/2" O.D., the air underwater technique is utilized. All tubes are pressurized with clean air to a minimum internal pressure of 100 PSI, then immersed and held a minimum of 20 seconds in clear, clean tap water with a surface free of ripples. While immersed, the entire tube length is examined for leakage.

Both techniques are conducted in accordance with ASTM B-338 and ASME SB-338 Section 11.4.