Document DGqavpwkG2V4aVnyQGNpX0zVa

HEADWORK PHIL SWAIN BRINGS ENGINEERING ------ . THEORY DOWN TO EARTH \ eroo eeoo eooo (SCOP) . (M3F) (690F) Abiolut* preiiura, pda VOLUME At protiure rliej, iq|. uroteS EtguJd water pet, (Ighlor, while taturettd steam 0t heavier. *t the critical preture (3206 Pda) both hev* the tome volume (0.0S03 cu ft per (b) nd, In fact, art the same thing ENTHALPY At prenure riset, the enthalpy (heot added above wotor at 32 F) riset for toturatecMfciuid water, but foils for satu rated steam until both become equal (903 8iu) at the critical pressure The ABC of Superpressure--2 Fimt, let's osview a few fundamentals: For each preseuro water boils at, there it a corresponding temperature called the saturation temperature. At. this corresponding pressure and temperature both the steam and the liquid water ere said to be saturated. Saturation pressure and temperature rise together, but not in proportion, until the critical point is reached ol 70S F and 3206 ptio (ib per eq in. absolute). Here (see curves), liquid and steam beeome exactly alike, so "liquid'* changes to ''vapor'* without adding hcot or in crease in volume. That's why critical boilers can moke steam without "boiling.'' Above 705 F, water cannot exist os a liquid no matter how high the pressure. At 60 F, one cubic foot of saturated water weighs 63*6 ib. At the critical point both the water and the steam will weigh 19.9 Ib. Afore information next month on critical pressure. 140 FIANT OFEtATIQN ANO MAINTENANCE SECTION powa we combat corrosion and searing ores In most industrial plants, metal-clad switchgear is under constant attack---inside and out. To pro tea against the effects of orciog, Westinghouse lines arc chutes with a true ceramic containing o high percentage of zircon, which has the highest melting poiat of aoy known material. Additional important factors io chute life that maintenance men appreciate: Westinghouse chutes will not absorb moisture, have dielectric properties comparable to porcelain. This switchgear employs the most effective method of arc extinction in use today. The arc is extinguished in split seconds and it is on the main contacts for only a fraction of this time. Result: less contact burning, less chute wear, less shock to the whole unit. Bondorixlng* best practical surface protection The best practical metal surface protection that we know of for switchgear is Bondcriiing. We Bonderize our metal enclosures after they're assembled so that every nook and cranny gets the full five-dip treatment. Then the enclosures ore paioted twice ood the paint sticki as though It is part of the metal. In Westinghouse outdoor switchgear there's no worry about corrosion on the undersurfaces, either. After assembly, we spray them with a heavy layer of rubberized coating. When you're planning switchgear installa tions, call in Westinghouse. And write now for your copy of booklet B-5306. Westinghouse Electric Corp., P.O. Box 868, Pittsburgh 30, Pa. .Moaio-C you can be SURE...if irS Westinghouse NOVEMSEI 1933 141