Oct. 1, 1946. 2,408,637 E. HART DOUBLE CASING HIGH PRESSURE PUMP Filed Julyäl',- »1944 ' A2 sheets-Sheet 1. ...mi ~_ »NVEN‘TOR y ATTQRNEY Octyl, 1946. _ E, HAR-l1 2,408,637' ' DOUBLE CASING HIGH PRESSÚRÈ PUMP I NN Filed July 5l, 1944 2 Sheets-Shee‘kf 2 mYm ||| ml âmwM-KlZ] k_ MNZ. .Y INVENTQR 1 EDWARD HART BW if@ ' ATTORNEY 2,408,637 Patented Oct. 1, 1.946 f UNITED « >_s'l‘irrs’s PATENT formes Edward Hart, San Marino, Calif., assignor to A. 0.`-~ Smith Corporation, Milwaukee, Wis., a corpo ration of NewYork Applieatión July 31, 1944, Serial No. 547,423',> " f2 claims. » (ci. loss-10s) rvaway vand sectioned showing the. right hand .end This invention relates to kdouble casing high pressure pumps of the multi-stage rotary >iin „ peller type wherein the vpump housing `for the of the pump; and y impellers is of cast construction embodying pas endofthepuinp~` ~ w. . . Fig- 2 is a similar section throughthe left'hand ' The pump comprises* a' cast lpump housing I having a rotaryV shaft 2 extending longitudinally axially thereof. The left hand end of housing I is bolted to- the cover plate 3. and the right >hand sages and volutes giving. a high efliciency to the pump,.and wherein an .outer c_as_ing surrounds thepump housing and is adapted tocontainfluíd >under pressure to support the pump housing end has a slip joint sealed by the annular ring against tension stresses resulting from the com pression of the fluid therein. 'I‘he fluid in the 10 5 and centering the housing in a separator piece forming the inner Wall of a ysuction chamber in casing is usually pumped :Iluid which is under the endr housing 4. End housings >tare .bolted _the same pressure as the ñuid being dischar-ged to cover plate 3 and housing 4, respectively, and contain bearings for the ends of the pumpshaft . Heretofore, the outer ca‘sings for such pumps have been of cast or similar construction requir 15 2. The shaft extends through the end of one kof >the housings 6 to be driven> by any suitable ing heavy walls to withstand »the high internal from the pump. ~ ' „ . _ , fluid pressures. Where corrosion was likely, plications; . means.. . , . . . . TheA housing I containsV the impellersA-.l seh either the metal of the casing throughout its cured on .the shaft 2' in volute >chambers 8.1111 ¿the thickness had to be` of an expensive corrosion resistant alloy, or else an added weight of some 20 housing. As manyimpellers ‘I may belemploy'ed as> desired Within “the limits of` proper' shaft alloy sheet liner >.had to be inserted therein and alignment and support, the pump illustrated properly vsealed against leakageiof 4fluid behind having ten impellers and being a ten-stage.~ pump. the same. Such pumps were expensive and heavy The inlet for the pump is` provided in en’d'hous in Weight, detracting from ytheir commercial ap 26 ing 4 Where the lateral intake 9 supplies fluid to a throated circumferential chamber I0 lead Y . The object of the present invention is to great- y ly reduce the cost of such pumps and to lighten ’ ing. to the first stage impeller Il. From impeller I I the fluid is directed through passages in hous the'iweight‘o‘f‘ theV same so that they may be em ing I to successive stages until it is ñnally'vdis ployed'more readily in competition with other charged through the central port I2 in the side types of pumps. 30 of the pump housing. ' According to the invention the outer casing In construction, the end housing 4 has a cir is composed of a number of relatively thin layers cular flange I3 thereon for Welding to the end of metal superimposed and welded along one or Vof the outer cylindrical casing I4 by thearc de more longitudinal seams and Welded to end ilange posit I5. The cover plate 3 is bolted to an end members or closures for supporting the pump 35 ñange member I6r Welded to the opposite end therein. Where corrosion is encountered, the of the casing I 4 by the arc deposit I 1. Welds inner layer is constructed of suitable corrosion I5 and I'I serve to secure _the members longi resistant alloy While the remainder may be of tudinally and the bolted end plate 3 and liange ' ' less costly steel, all of the layers being'utilized for the retentionv ofthe pressure fluid. Expensive casting operations yfor the casing 40 I6 provi-de for assembly of the pump. In .accordance with the invention, the casing I4 is constructed of a plurality of layers of rolled plate formed into superimposed cylindrical lay are eliminated, and due to the higher quality ers to provide a multi-layer construction in which of rolled stock of relatively. thin plates, the total wall thickness and Weight of the casing is con 45 each layer is in uniform pressure engagement With its adjacent layervor layers. _ sidera-bly reduced. The layers are fabricated ‘ In constructing the casing, the first layer I8 is in tight contact to effectuniform stress distri ñrst formed by rolling or pressing a i‘lat plate bution therein, While the flexibility of the sev to cylindrical shape and the longitudinal seam is eral layers provides, a structure more kfree from' fabrication stresses and more reliable in the con 50 welded, as by an arc deposit I9. Subsequent layers 20' are similarly formed and then applied ñning of the pressure ñuid. . either successively or at one time and tightened The accompanying drawings illustrate an em upon the inner layer by tension bands and then bodiment of the invention. Welded along the longitudinal seams 2I. As In the drawings: Figure 1 is a side elevation with parts broken 55 many _subsequent layers may be applied as may be 4. 3 necessary to provide a cylinder capable of with standing the fluid pressures involved, having re gard to the thickness of the layers and the strength of the metal. The drawings show four layers 20. In practice the layers should range between one-eighth and one-half inch in thickness in order that they be assured of proper quality of steel. The relatively thin plates are readily formed and applied without danger of internal 10 head secured to said flange, aligned bearings carried by said heads for a pump shaft, a pump enclosed in said casing and having a rotary shaft extending therethrough and mounted in said end bearings, a plurality of impellers mounted on said shaft and operative in series to provide a high pressure discharge for the vpumped fluid, said vpump being supported at its ends only by said end heads and being continuously and radially spaced stresses from fabrication, and the shop equipment , for constructing the casing from such layers-is simple and inexpensive. Furthermore, the rela‘tively thin layers provide a structure which is welded to said casing at one end and a flange welded to the casing at the other end, an end ' from said outer casing to provide a closed cham Iber therebetween for substantially the full length y of the pump, and a lateral discharge outlet welded highly flexible to stresses and which effects »a‘ 15 to saidfcasing.substantially centrally thereof in ready and uniform ‘distribution of the working alignment with the discharge port of the pump y _and connecting »with the space between said pump The inner layer I8 may be of non-corrosiveandfcasing to dispose fluid in Said space under alloy of a composition known to be resistant to circumferential and longitudinal pressure pro attack from the fluid being pumped, and is welded 20 tecting the pump against internal fluid pressures into the structure in a manner adapting it to duringoperation of the pump. take its share of stress under working loads, 2. In a double casing high pressure pump of along with the other layers.A the class described,l an outer cylindrical casing The casing I4 has a central discharge outlet i2 >constructed of a plurality of superimposed layers disposed in alignment with the loutlet port I2 of 25 of rolled metal plate welded in close pressure en the pump housing I. The space or chamber 2t gagement with one another for withstanding high between housing I and casing III serves to- retain internal fluid pressures, anLend head providing an pumped fluid under pressure from said outlet I2 inlet to said pump for fluid to be pumped welded and to thereby surround the pump housing I dur yto the end ofthe casing and another end head ing operation with fluid under pressure. .30 >removably secured to the casing, a pump enclosed By reason of the protection of housing I by in said casing and havinga rotary shaft extend the external vfluid pressure the housing can be ing-therethrough and mounted in said end heads, thinner and much lighter in weight, thereby mak~ a plurality of impellers mounted on said shaft and ing the casting of it less expensive and its han operative in series to provide a high pressure dis dling during machining and fabrication of the charge `for the pumped fluid, said pump being pump less difficult. supported only by said endV heads and being con The outer casing withstands both the longi tinuously and radially spaced from said outer cas tudinal and circumferential pressure of the fluid, ing throughout substantially the full length of the thereby relieving the pump housing of all ten pump, and means comprising a discharge outlet sion stress during operation of the- pump. l40 disposed substantially centrally of the casing and The invention may have various embodiments connecting with the space between said purnp and within the scope of the accompanying claims. casing to provide fluid between the pump and I claim: casing under a circumferential and longitudinal 1. In a double casing high pressure pump of pressure equal to the pressure of the fluid at the class described, an outer cylindrical casing » 45 said discharge to protect the pump against in constructed of a plurality of superimposed layers ternal fluid pressures during operation of -the stresses throughout the same. of rolled metal plate welded in close pressure en gagement with one another for withstanding high internal fluid pressures, a lateral intake head pump. EDWARD HART.