EQUIPMENT Increased Tankage for Petroleum Remote tank g a g i n g and centralized control permit increased tank utilization at Esso tank farms C O L L E G E S T A T I O N , T E X . - M o s t re- gaging system used sonic transducers fineries now face a meed for increased a n d sonic stilling wells w h e r e b y t h e t a n k a g e for c r u d e , f e e d stocks, a n d fin- transducers project sonic waves through ished products. Considering construc- the liquid to its surface a n d b a c k to the tion costs to r u n $ 1 . 0 0 or more p e r bar- originating transducer. High viscosity r e l of capacity, ecorLomy dictates using of some stocks limited sonic measurall available tanlca_ge, said William ing's value. Knesby of Esso R e s e a r c h and EngineerA second level measuring device uses i n g to a recent Syroposium on Instru- an oscillator to g e n e r a t e a r a d i o frementation for t h e ^Process Industries. quency signal emitted from- a sensing A n d with refinery limits running far in element and an antenna w h i c h just excess of anticipated capacities or with touches t h e liquid surface. Contact l o w unit holdup tiroes, need is recog- with t h e surface b y the a n t e n n a indin i z e d for providing immediate inven- cates a n u n b a l a n c e to a controller that tory information to accounting and op- drives a servo motor raising or lowering erating units. A l l this will come the sensing element. Connected t h r o u g h improvements in r e m o t e tank through gears to t h e servo motor, high gaging and automatic control tech- accuracy foot a n d inch potentiometers niques, says K n e s b y directly indicate t h e level. L i q u i d temUntil recently, m o s t storage tanks perature is determined b y a resistance h a d w h a t is now considered a crude t y p e multielement averaging t h e r m o m m e a n s of determining level—a float with eter, and switched automatically in t h e cables, pulleys and weights, a n d gradu- gage. ations o n a tank's si
