Pressure drains

Locate leaks Apply soap solution to tape bleed holes and threaded connections depressure when tests are done. Block in N2 and check for loss of pressure. Check all connections. Same as in Step 1. Tag flanges to identify leaks tighten or repair leaks each time a system is pressurized, drain condensate at low-point bleeds. 

The turbine case pressure was increased by raising the pressure in the air-cooled surface condenser. This was accomplished by shutting off several of the air fans, which, in turn, increased the condensing temperature of the exhaust steam. But why would raising the turbine case pressure drain the turbine, anyway After all, increasing the surface condenser pressure also increased the pressure in the drum that the turbine case drained to. 

YES OXYGEN, positive end-expiratory pressure Drain vesicles—unroof large blisters and irrigate area with... 

The condenser is cooled by the circulating water system which typically incorporates three electrically driven pumps loss of one pump will call for a power reduction, but will not yield a turbine trip in the short term. The condensate is pumped forward to the dearator (or the feedwater tank) through low pressure heaters and a condensate cleanup system with ion exchange filters by means of three 50% condensate pumps. The drmnage from the heaters is pumped forward through the cleanup system by means of a dedicated low pressure drain pump. 

That analysis is continuing, investigating problems identified by the Peer Review (e.p., lack of pressurizer draining prior to vessel breach), evaluating the impact on the results of... 

As the accident continued, the water and steam mixture leaving the open PORV had been collecting in the Pressurizer drain tank. About 15 min into the accident, the rupture disc on the pressurizer drain tank, which was designed to limit tank overpressure, blew and allowed additional radioactive water from this tank to run down to the containment sump (Kemeny, 1979). The water was periodically pumped from the sump into a storage tank of the auxiliary building, adjacent to the containment. 

The foregoing discussion leads to the question of whether actual foams do, in fact, satisfy the conditions of zero resultant force on each side, border, and comer without developing local variations in pressure in the liquid interiors of the laminas. Such pressure variations would affect the nature of foam drainage (see below) and might also have the consequence that films within a foam structure would, on draining, more quickly reach a point of instability than do isolated plane films. 

As stated in the introduction to the previous chapter, adsorption is described phenomenologically in terms of an empirical adsorption function n = f(P, T) where n is the amount adsorbed. As a matter of experimental convenience, one usually determines the adsorption isotherm n = fr(P), in a detailed study, this is done for several temperatures. Figure XVII-1 displays some of the extensive data of Drain and Morrison [1]. It is fairly common in physical adsorption systems for the low-pressure data to suggest that a limiting adsorption is being reached, as in Fig. XVII-la, but for continued further adsorption to occur at pressures approaching the saturation or condensation pressure (which would be close to 1 atm for N2 at 75 K), as in Fig. XVII-Ih. 

Dissolve I ml. of benzaldehyde and 0-4 ml. of pure acetone in 10 ml. of methylated spirit contained in a conical flask or widemouthed bottle of about 50 ml. capacity. Dilute 2 ml. of 10% aqueous sodium hydroxide solution with 8 ml. of water, and add this dilute alkali solution to the former solution. Shake the mixture vigorously in the securely corked flask for about 10 minutes (releasing the pressure from time to time if necessary) and then allow to stand for 30 minutes, with occasional shaking finally cool in ice-water for a few minutes. During the shaking, the dibenzal -acetone separates at first as a fine emulsion which then rapidly forms pale yellow crystals. Filter at the pump, wash well with water to eliminate traces of alkali, and then drain thoroughly. Recrystallise from hot methylated or rectified spirit. The dibenzal-acetone is obtained as pale yellow crystals, m.p. 112 yield, o 6 g. 

In a 500 ml. Pyrex round-bottomed flask, provided with a reflux condenser, place a mixture of 40 g. of freshly-distUled phenylhydrazine (Section IV.89) and 14 g. of urea (previously dried for 3 hours at 100°). Immerse the flask in an oil bath at 155°. After about 10 minutes the urea commences to dissolve accompanied by foaming due to evolution of ammonia the gas evolution slackens after about 1 hour. Remove the flask from the oil bath after 135 minutes, allow it to cool for 3 minutes, and then add 250 ml. of rectified spirit to the hot golden-yellow oil some diphenylcarbazide will crystallise out. Heat under reflux for about 15 minutes to dissolve the diphenylcarbazide, filter through a hot water funnel or a pre-heated Buchner fuimel, and cool the alcoholic solution rapidly in a bath of ice and salt. After 30 minutes, filter the white crystals at the pump, drain well, and wash twice with a little ether. Dry upon filter paper in the air. The yield of diphenylcarbazide, m.p. 171 °, is 34 g. A further 7 g. may be obtained by concentrating the filtrate under reduced pressure. The compound may be recrystallised from alcohol or from glacial acetic acid. 

Fig. 4. Diagram of a hoUow-fiber ultrafilter filtration system where A corresponds to the retentate reservoir B, circulation pump C, pressure gauge at module inlet D, ultrafilter module E, permeate reservoir F, pressure gauge at module outlet G, value to control module outlet pressure and H, drain...

A variation of the same principle is the DDS-vacuum pressure filter which has a number of small disks mounted on a shaft which rotates discontinuously. The cake is formed on both sides of the disks when they are at the bottom position, dipped into the slurry. When the disks come out of the slurry and reach the top position, hydrauhcaHy driven pistons squee2e the cake and the extra Hquid then drains from both sides of the cake. The cake is removed by blowback with compressed air. 

In hquid service the lines must constantly slope downward toward the transmitter from the taps to prevent possible gas pockets. In gas service the lines should drain to prevent condensate accumulation or, if the condensate is used to transmit the pressure from the taps to transmitter, the condensate legs must be of equal height. 

Filtration installations include wrapping the trench of a pavement-edge drain system to prevent contamination of the underdrain placement behind retaining walls and bridge abutments to prevent contamination of the sand blanket placed against the stmcture to allow dissipation of pore pressures in order to avoid failure of the stmcture as silt fences to allow surface mnoff from a site while retaining the soil suspended in the mnoff and on earth slopes beneath larger stone or other overlay materials to prevent erosion of the slope as water escapes from the interior of the slope. 

The possible remedial and preventive actions are hot soaks and drains during cooldown to help remove soluble deposited material, chemical cleaning to remove corrosion products and reduce the pressure drop (see Metal surface treatments), and reduced corrosion product transport into OTSG using amines other than ammonia in feedwater (14). 

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