EVALUATION OF HIGH TEMPERATURE INSTRUMENTATION FOR DYNAMIC ANALYSIS. ENCAPSULATED STRAIN GAGE INSTALLATION FOR USE IN STEAM ENVIRONMENT,
Abstract:
An inspection of the interior of a steam drum aboard the USS DECATUR revealed a crack extending around the upper half of the manway. The stresses causing the failure were thought to be highly concentrated therefore, it was necessary to use a strain gage with a short gage length 18 in that could operate in a saturated steam atmosphere at 1200 psig. Because there were no known cements or protective coatings which were capable of operation in the proposed environment, it was necessary to develop a special gage installation. The unit developed consisted of a strain gage cemented atop a stainless steel shim which had been tack welded to the test specimen and then sealed by silver soldering. This type installation was capable of meeting the requirements. Detailed instructions for construction, installation and calibration are described in appendixed Instrument Standards. Author