Tubes, hydrostatic testing

A. Fifteen secondary side hydrostatic tests with secondary side pressurized to 1-1/4 times the design pressure and the primary side pressurized so that the tube differential pressure does not exceed 820 psid (test condition) ... 

Methods used for hydrostatic testing of compressed gas cylinders and tubes are as follows ... 

Storage banks of DOT/TC cylinders should be checked for the last hydrostatic test date to ascertain that the cylinders are within the allowable time period between tests. Cylinders in these banks must be retested every 5 years. DOT/TC cylinders must be filled and periodically retested in accordance with appropriate regulations. Retesting is not required for ASME storage tubes. 

C-I8 Methods for Acoustic Emission Requalification of Seamless Steel Compressed Gas Tubes. Prepared to identify and describe the various acceptable Acoustic Emission Test (AET) methods that can be utililized in lieu of hydrostatic test in the water jacket to retest certain tubes as mandated by 49 CFR, 173,34 and/or Transport Canada regulations. Includes two acceptable methods of AET. Test procedures, use of special equipment and instrumentation specifications are included (22 pages). 

As a supplement to a hydrostatic test and normal filling procedures to ensure the integrity of the cylinder or tube. 

Testing Upon completion of shop fabrication and also during maintenance operations it is desirable hydrostatically to test the shell side of tubular exchangers so that visual examination of tube ends can be made. Leaking tubes can be readily located and serviced. When leaks are determined without access to the tube ends, it is necessaiy to reroll or reweld all the tube-to-tube-sheet joints with possible damage to the satisfactoiy joints. 

Performance of the Sapphire NMR Tube. The tube and valve are sufficiently light weight and symmetrical that they spin and achieve a typical resolution of about 1 Hz. In hydrostatic pressure testing, the burst pressure of one tube was found to be approximately 14,500 psi, and it is therefore believed that operations up to 2000 psi may be carried out with a reasonable margin of safety. Obviously however, all due caution must be exercised and operator exposure to a pressurized tube must be avoided. It is as yet unclear whether extended use will eventually affect the performance of these tubes. In our hands, the tubes have been operated without incident, over a period of two years, from -140 to +150°C at nominal pressures up to 1200 psi. 

The slip point of a fat is the temperature at which a column of fat, of specified length, starts rising in an open capillary tube under the influence of a hydrostatic pressure under the specified conditions of the test. 

Barriers and controls (5) All tubing and/or equipment connections have been field-welded to ensure an adequate seal. System is visually inspected on an annual basis and hydrostatically leak-tested every 5 years. 

Barriers/Controls 5) All tubing and/or equipment connections have been field welded to ensure an adequate seal. System is visually inspected on an annual basis and hydrostatically leak tested every 5 years. Controlled Risk Assessment 5) Barriers/controls considered adequate. The addition of a dye-penetrant analysis of all field joints would further reduce the possibility of hazard risk exposure. Enforced No Smoking policies around oxygen panels by the hospital staff and the patients will also decrease the risk potential. A Controlled RAC of2E is assigned. 

Precision measurements of the in situ pH below a depth of about 400 m require separate glass and reference electrodes with electrolyte junction and pressure compensation. A pH electrode withstanding IS 000 dbar has been described by Disteche (1959, 1962). Ihe first practicable deep-sea pH electrode was introduced by Ben-Yaakow and Kaplan (1968) and improved by Ben-Yaakow and Ruth (1974). The electrode can stand 6700 dbar hydrostatic pressure and has been tested to a depth of 5000m. The pressure is compensated for by replacing a part of the glass electrode housing by Tygon tube. The accuracy is 0.02 pH units. A correction for a shift of the asymmetry potential (2 mV for 6700 dbar) was included. 

After the structural test, the unit was removed from the test rig and hydrostatically pressure-tested at 200 psig on the shell side and 1000 psig on the tube side. These pressures were held by the unit for several minutes without pressure decay, which illustrated that the unit was still leak-tight. 

Waterproofness is an indication of a particular membrane material s ability to withstand a 60 cm hydrostatic pressure head. The apparatus employed in this test is shown in Fig. 8-34. The membrane film is affixed at the bottom end of the J-tube and water is then carefully introduced to an overall height of 60 cm above the level of the membrane. 

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