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Why This R-P&C Valve Suits the Power industry This cast steel R-P&C Gate Valve with pressure sealed bonnet provides continuous tightness when exposed to the varying con ditions of high pressure steam generation. The inside bonnet is forced against a metal sealing ring by pressure in the valve. A compensating wedge permits easy opening and closing by. either hand or electric power. This valve is always tight, yet easy, to operate. Cast steel construction is designed for pressures to 1500 lbs., temperatures to 1100s F. Sixes: Oates 2J>* to 14'; Globes 2^' to 8'. Full specifications are shown on page 144 of the No. 9 R-P&C Valve catalog. 234 f HYDRAULIC GOVERNORS i i ------------- - Mlv hu permitted the retel.ln, to gradually return to it, origin* tlon, in the eeme time the enjioe took, return to It, orijin.l ,PMd ,nJ bollsrms lo return to the vertical W Note that in this governor ibe tern porary apced droop <compmtiUotO / applied by changing the eflectlw length of the connection between tho speeder rod and pilot tsIvo. Chongbt connection length couses ipeed droop for the some reason that changing the compression of the speeder spring does. Powsa, March, p 73. Each method d causing speed droop changes tho engine speed at which the pilot valve tesla the control ports. Strictly speaking, only isochronous governors are true constant-speed governors. All mechanical governors, sod some hydraulic governors, have perma nent speed droop and arc "nonitoehronous" 'because engine steady speed is slightly different at different loads. But the speed change from full load to no load (speed regulation) la usually only 3 to B%. Since such governors hold engine steady speed substantially con stant, they too are classed as constantspeed governors. FEED PUMP Cttltfawrf trOM IU cast-iron plungers for high feedwater temperatures. Though east Iron corrodes foster, it's cheaper and easier to replace, and may cost less In the long ran. Commonest liquid-piston packing Is fibrous type of laminated layers of dock with a rubber or neoprene binder. It l> soft or rockhard, depending on euro of hinder. 1 find soft grade Is good for water lo 180 F. Rockhard Is used to 240 F. Preformed cupo of molded dodt and neoprene are easy to install, reauire no fitting. They are good up to 250 F. Suction Conditions. Perhaps most headaches with reciprocating tod pumps are from low suction pressures. Even at slow speeds these pumps most have enough suction pressure to over come friction and to lift suetion v*to sgelnst spring tension. Pressure needed fa called net positive suction htatt (npsh). This varies with each size sod pump type, with different eapstltloand with different sizes and type* lintjid valves and springs. let's sav pumn endneer advises 3-J" ns> npsh for your capacity. TTil* n,e*fl1! measure in suction line ar name m be at least 3.5 pat greater than Uqnm* vapor pressure at suction temperate*- You can provide npsh In many having water supply above pump * Pirhmtuth Pmutr Slclii* ii dttigntdfor an uhimatt ttai iftie units, tech if100,000 kihnuatt nemtplaU rafiaritj) More Kilowatts for a Growing Region The system-wide generating capacity of Virginia Electric and Power Company was increased to nearly 1,000,000 kilowatts early in 1953 and in 1954 it will be further augmented by an additional unit of the Portsmouth Power Station near Portsmouth, Virginia. The initial unit of this new station, a 100,000 kw preferred standard machine, is already "on the line". Stone & Webster Engineering Corporation was retained for the design and construction of the new facilities. STONE & WEBSTER ENGINEERING CORPORATION A SUBSIDIARY 0/ STONE & WEBSTER, INC. rown ' 'i t '?W' I-'--A li K? '