Pressure leaks

Implement procedures for leak/pressure testing of jacket, coil or heat exchanger prior to operation... 

Site-erected pipework, once complete, must be pressure tested for safety and freedom from leaks. Pressures will be 1.3 times the... 

Test methods will logically include tensile testing to measure strength, and hydrostatic testing at a pressure with a liquid to test for leaks. Pressures not exceeding 300 mm Hg pressure (internal heart fluid pressure) could be employed for this purpose. 

Leak pressure The value of increasing inlet static pressure at which the first bubble occurs when an SRV is tested by means of air under the valve disc and a specified water seal on the outlet. 

Fig. 10.12 Schematic representation of two melting mechanisms observed by Janssen (24) with PP processed in a double-flighted 47-mm counterrotating TSE operating at low rotational speeds, (a) Melting when the die pressure was set at the low value of 50 psi, where chamber-to-chamber leak pressure backflows are negligible, (b) Melting under the high die pressure of 2700 psi, which enables leak backflows, which result in chamber solid bed compaction and introduce the possibility of dissipative mix melting. [Reprinted by permission from L. P. B. M. Janssen, Twin Screw Extrusion, Elsevier Scientific, Amsterdam, 1978.]...

The factors suggested for consideration are but the major ones, and not necessarily all of those. A separate check list should be made by the supervisor for each job. One final factor which should always be considered is the effects that grouting will have on measurable parameters, such as seepage, leaks, pressure, ground or structure movements, water levels, etc. Whenever it is possible to relate the effectiveness of the grouting operation... 

Sun Jianhua, The porous-leak-pressure barrier explosion of the automatic air-door that is used in the mine, China Mining Magazine, 2011.20(3) 105-106 China Coal Society, 2008, 33(8) 903-907(In Chinese). 

Finding gas leaks (pressure hazards) can be difficult. After a gas has leaked into the ocean of air around it, obvious symptoms of the leak (odor or a cloud) may disappear. Several methods of detecting gas leaks are ... 

Freeze, vacuum, batch (conduction) drying temperature serum, -9 to -12 °C plasma, -20 to -25 °C penicillin -28 to -32 °C size vacuum pump to remove the water vapor avoid air leaks pressure 10 to 200 Pa or 1/4 to 1/2 the vapor pressure at the temperature 7-8 h drying cycle 2800 kj/kg water sublimated. Continuous ... 

At the other power plants, the system is found at lower elevations of the main building. In the case of a coolant leak, pressure relief in the ALS relies on passive condensing devices, i.e. pipes submerged under water on two decks of the PSP. 

Steam Leaks from Steam Pipes (Visible) The most common causes of steam leaks come from holes in steam pipes and threaded pipe connections in a steam and condensate system. Steam flow through a leak can be calculated using an orihce equation, which is based on the diameter of the leak, pressure at the inlet of the orifice, and pressure at the outlet (atmosphere). 

In the case of a channel failure, the moderator acts as an energy-absorbing cushion, preventing failure of the calandria vessel. Even for beyond-design-basis severe core damage accidents, where a number of channels are postulated to fail, the calandria may leak (pressure relief rupture discs) but would retain its gross structural integrity. 

Leaks may be detected by special hydride detectors, chemically treated paper tapes that will change color when exposed to phosphine, detector tubes, and other detection devices. If leaks are detected, the main source of gas supply should be shut off. Evacuate or purge the system with inert gas to ensure that those repairing the leak cannot be exposed to phosphine. After repairing the leak, pressurize the system with an inert gas such as helium, and check to see that leaks have been corrected before introducing phosphine into the system. 

Not only does the secondary ion yield vary with the O2 leak pressure used, but so too does the sputter rate (a decrease in sputter rates is commonly observed)... 

Ghoniem GM, Roach MB, Lewis VH et al (1990) The value of leak pressure and bladder compliance in the urodynamic evaluation of meningomyelocele patients JUrol 144 1440-1442... 

---