Document 1QkQ49MrJ1oyXyjv6bRDX1Xrj

s KJOHICWDI Radioactivity, Magnetism Assure Edward Valve Soundness The technician above is using Cobalt*#), a radioactive isotope obtained from U. S. and Canadian Atomic Energy Commissions in the.radiographic examination of an Edward Fig. 4006Y cast steel valve. Using gamma-rays, the radiographic technique gives photographic evidence of the internal structure of metals, instantly reveals internal voids or weaknesses not capable of detection by any other method. Ovr nj,000 eepeffres m * Si wntci or* tSM hr refumut. HIM li fo/W hr loop upirhic*, utihi nggtfvn prevfcg iwUrhl momSwis oJfdworrfVi Radiographic inspection is an old story at Edward. In use since 1928, Edward has built up a file of over 203,000 radiographic negatives attesting to the soundness of valves already in service. And the backlog of experience gained in applying and interpreting radiographic methods over the years assures Edward customers of the greatest possible measure of protection from this technique. Radiography is only one of many methods, some old, some new, used in thoroughly inspecting all materials that make up Edward Valves. A new testing procedure is illustrated at right--a magnetic- electronic device which tests bar stock entering the Edward plant, assuring 100% soundness and uniformity in the materials used for stems, studs, and other vital valve components. By measuring variations in electrical and magnetic characteristics, this unit reveals any deviations in hardness, chemical analysis, or grade, and any internal cracks or structural differences. It can even tell whether two bars came from the same or different "heats." Inspection procedures like these illustrate the determination at Edward to quickly adopt every modern technological develop ment which permits further verification of the superiority of our materials, manufacturing methods or designs. These continual, checks have helped to build the reputation for dependability in service which is our most valuable asset--and one which we arc Mupaeifc-EIerlrwafe SiWd checks every fork hr * sportster sbev* detects afi (i*<h or veid* ft oV *h*mrcf toogpoiflipo or Mono! tfnvtero. determined to protect at all costs. Valves, Inc. iProrMl Another c HOW TO CUT HTENANCE COSTS roper Valve Packing the ere***1 single hem of valve maintenance today i# the ^replacement of packing. In good, modern valve design* *riil causes of maintenance have been largely eliminated, . ,| the major regular maintenance item requited. HfTj1Simple rules will allow the plant operator to drastieaOy r^proi on packing maintenances TiO SHOULD FfT PERFECTLY. Too much packing yilVe operation difficult; too little packing aoon results in Voiced non working csrelully with coil packinitg cian get -*Tj * percentase of eases. However, the use of pprreeftormed *fricie cuti 1to0 exactly ntul tmhe pjacck>inugv chamb...e.r..,..i.n..s.aurpee*rafecj t and1 a-*t a fraction off the lime aend trouble. different TYPES OF PACKINO ARE BETTER - qME. Packing in a valve chamber is subjected to two v oppoiingrequirementt. First, it must be soft enough to be iqueeted lightly against (he valve stem ano packing cham ber for a perfect seal. Second, it must not be so soft that it is ex truded from the ends of the packing chamber when line or gland pres sure is applied. A combination of two different type* of pack ing ring* best meets these opposing require ments. The outer rings adjacent to junk ring and gland should be re inforced for additional, stiffness, while the cen ter rings should be of a softer variety for maxi mum scaling effect. 3. PACKINGS SHOULD BE LUBRI CATED. For easier valve operation, pack ing materiala'ahould built-in lubricant--generally Graphite or Mica, Of these ipbite is much more satisfactory in providing easier valve o. |CH STEM PITTING. Packing should be specially treated to iau elcctrolytk corrosion of stainless steel valve stems. In Ion. if valves are to be subjected to hydrostatic tuts or will tttd lor s long period before installation, the packing should terprooled to prevent ebsorption of moisture and subsequent Ion, or packing deterioration. CK-DESIGN OF VALVE. Valve design plays a vcry'imporpart in determining packing life. Designs which provide an nre backseat, and remove the packing from high temperature tretch packing life. Correct proportions in the packing her are also important--avoid design* that call for ealrcmely picking rings, since these tend to reduce packing life, ior* esn avoid packing problems by following one rule which mpUince^with all those listed above--to use Edward^EVaj- "'lung norc siiksut* iuuu--* vhe same general composition with, (or additk~.~ --_____, jacket of asbestos strands reinforced by metil wires. All sets ally treated to eliminate stem pitting and waterproofed to `.corrosion. They can be installed in a minimum of time and sda the longest possible Service life, ksr Bulletin 12-R for complete information. t#WARO VALVES, Inc., Subsidiary of ROCKWELL MANUFACTURING COMPANY ;J220 W. 144th STREET EAST CHICAGO. INDIANA *JMAMD AMOlR HOP tllO-UMI * BLOW-OFF NON-ftlTURN "SCR OATI OA0I AND INSTRUMENT SCtllP STRAINERS corrftMMT tvo. ww*o V*.vee. *. `IcchnijraTups Pressure Drop in Steel Valves 2 Inches and Smaller In valves 7 in. snd smaller, pressure drop is important for two principal reasons. First, obviously, from the standpoint of need foss -- which may be unimportant in some instances, but have a serious economic signif icance In other applications. Second, pressure lots is due primarily to turbulence within the valve, which la also the principal cause of wear-producing vibration and. erosion. Pressure loss in a valve therefore aervet as e good index of ita service life, other factor* being equal. The chart below, based on tests in the Edward laboratories, shows the pretture drop characteristic* of various types of valves, with sn elbow {tiling included for purposes of comparison. These are given in terma ol. pressure drop coefficient and pressure drop in equivalent pipe diameters, fn calculating these latter value* the pressure drop coefficient of f--.02 for itandard weight pipe was used. , I l^ n;v 1 11; I ` ;*V J> I. Typical 90* Stein Gtob* Volv*. II. IntOiMd tins, screwed In seal globe nhe. Edward Rg. 444, 440, dS S. HI. tncOned stem. Integral seat globe vole*. Edward Fig. 3X14, 931. 946. IV. Typical unoO got* vote*. boat dlorseter 70 per cent of pip* dloret'er. V. Angle step rebt. fdwerd fig. 443, 449,949, VI. Elbow, screwed or sockel welding end. The user can readily calculate the cquivalent'length ol pipe from the standpoint of pressure drop for certain email valve type* wih this chart. For example, a I In. inclined stem globe valve with integral seat will have pressure drop equivalent to 120 la. or 10 fl. of 1 in, pipe, end the 2 in. size of the same valve will have a pressure drop equivalent to 240 in. or 20 ft. of 2 in. pipe. .The superiority of inclined stem construction lor globe vatves in this size range is obvious--note that the integral seat Y-type globe valve has a pressure lots 17% lets then tne 90* stem type globe valve. Hie pressure loss characteristics of Y-typo globe valves compare quite favorably with gate valves. The tighter hut off obtained, ability to throttle' and Other tdvan' tages realized with these globe valves, make desirable their use in many applications. i.V5 IS