Joints checking

Immediately after the running test, any compressor intended for toxic, hazardous, flammable, or hydrogen-rich service should be gas tested with an inert gas to the maximum seal design pressure. The test is held at least 30 minutes and the casing and its joints checked for leaks, using a soap bubble method or other suitable means for leak detection. When no leaks are detected, the compressor will be considered acceptable. 

Besides large-diameter pipes, ultrasonic testing is used for checking the welded joints of drill bits, components of wind-driven electric plants, welded joints of light alloys and non-metallic materials, for an integrated inspection of various objects. A range of training aids developed at the Institute allows the operators to be trained effectively. 

Tlie indi ddual cells are assembled into batteries after a leakage test to check for faulty welding joints in steel containers or cracks and improper seals in the plastic encased cells. Cells that are to be delivered without electroltye are emptied after the fomiation cycles. Tlie steel-cased cells hav e to be separated by mechanical means to prevent intercell shorts and are often assembled into wooden crates. Tlie cells in plastic cases can be cemented together or strapped with tape. 

Rules for the welded fabrication of pressure vessels cover welding processes, manufacturer s record keeping on welding procedures, welder qualification, cleaning, fit-up alignment tolerances, and repair of weld defects. Procedures for postweld heat treatment are detailed. Checking the procedures and welders and radiographic and ultrasonic examination of welded joints are covered. 

Bolted joints are friendlier than quick-release couplings. The former are usually dismantled by a fitter after issue of a permit to work. One person prepares the equipment and another person opens it up the issue of the permit provides an opportunity to check that the correct precautions have been taken. In addition, if the joints are unbolted correctly, any trapped pressure is immediately apparent and the joint can be remade or the pressure allowed to blow off. In contrast, many accidents have occurred because operators opened up equipment which was under pressure, without independent consideration of the hazards, using quick-release couphngs. There are, however, designs of quick-release couphngs which give the operator a second chance. 

Check the condition of the cable insulation, its termination and jointing. Motor connections should always be made... 

All the joints, particularly power joints at the main busbars, tap-offs and cable ends, should be checked... 

In a draw-out MCC all current-carrying components should be periodically checked for their silver-plating, proper contact area, spring pressure and tightness of joints (this procedure can follow the manufacturer s maintenance schedule) or at least during the six-monthly or yearly maintenance check ups of the busbars and the busbar joints as noted above. The contacts or their springs may be replaced when the contacts are worn out or... 

Random checking of bolted connections for proper jointing and tightening... 

This test is applicable to all outdoor metal-enclosed switchgear and controlgear assemblies, as in lEC 60298, lEC 60694 and ANSI C-37/20C. The enclosure to be tested should be complete in all respects including its mounts, bushings (for HT switchgear assemblies, 1 kV and above) and wiring. One or more vertical units can be tested simultaneously as may be convenient, but not more than 3 m panel width can be tested at a time. For a multiple unit switchboard, however, at least two vertical units should be tested together to check the joints between the units. 

After catalyst charging and the flow vs. RPM measurement is done, the reactor should be closed and flushed out with nitrogen while the impeller runs, until O2 drops below a few tenths of a percent. Then a static pressure and leak test should be made by turning off the forward pressure controller and the flow controller. If an observable drop of pressure occurs within 15 minutes, all joints and connections should be checked for leaks and fixed before progressing any fijither. 

In one plant a mechanic did not check the tag number and broke a joint that had been tagged for an earlier job the tag had been left in position. Tags should be removed when jobs are complete. 

Cascading effects Check valve Clogged (of filter) Consensus standard Conservation vent Dike, berm Discharge valve Division (in electrical area classification) Downspout Expansion joint Explosion proof Faucet... 

Determine tool Joint outside diameter. Tool Joint box should have sufficient OD and tool Joint pin sufficient ID to withstand the same torsional loading as the pipe body. When tool Joints are eccentrically worn, determine the minimum shoulder width acceptable for tool Joint class in Table 4-101. Check the inside and outside surfaces for presence of cracks, notches and severe pitting. 

Check slip areas for longitudinal and transverse cracks and sharp notches. Check tool Joints for wear, galls, nicks, washes, fins, fatigue cracks at root of threads, or other items that would affect the pressure holding capacity or stability of the Joint. 

Random check 10% of the Joints for manufacturer markings and date of tool Joint installation to determine if tool Joint has been reworked. 

Check for box swell and/or pin stretch. These are indications of over-torquing, and their presence gready affects the future performance of the Joint. 

Some of the ultrasonic systems include ultrasonic transmitters that can be placed inside plant piping or vessels. In this mode, ultrasonic monitors can be used to detect areas of sonic penetration along the container s surface. This ultrasonic transmission method is useful in quick checks of tank seams, hatches, seals, caulking, gaskets or building wall joints. 

Make periodic checks for leaks by applying soap solution to joints and seals. 

The flue gas exit stack should be checked for cold-end sulfuric acid attack, fouling front ash and expansion joint cracking. 

X 10 N and the value obtained by the simplest form, 1.45 X 10 " N m n = 918 and a = 0.31 nm for Equation 21.1). These comparisons imphed that the measurements were consistent with the theoretical predictions. The deviation between the rupture length of 260.9 nm and the fitted-contour length indicated that the polymer chain was not fully stretched at the rupture event. The reason for this was that the rupture event was a stochastic process and was dependent on many factors such as pulling speed, bond strength, and temperature. The vahdity of the freely jointed (FJC) model (dashed fine) was also checked ... 

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