GB1353554A - Centrifugal pumps - Google Patents

Abstract

1353554 Making pump casings SIGMA VYSKUMNY USTAV CERPACICH ZARIZENI POTRUBI A ARMATUR ODSTEPNY ZAVOD 12 Nov 1971 [14 Nov 1970] 52774/71 Heading B3A [Also in Division F1] A centrifugal pump casing is constructed from at least two welded together sections 11, 12 which are generally shaped as complementary segments of a sphere or ellipsoid, and which have pre-formed or welded on members 13, 15, 16 which define at least one suction port, one discharge port and one further opening for connection of the driving mechanism. The inner working surfaces of the casing are provided with a layer of corrosion resistant material. Hemispherical sections, e.g. pressed from sheets of stainless or low-alloy steel, are supported on and spot welded to ring elements 51 to form a spherical casing. Openings 14, 20, 21 are provided and members 13, 15, 16, which are forged from material similar to that of sections 11, 12, are welded to the sections around the openings to provide the connection opening, inlet and outlet respectively. Alternatively members 13, 15, 16 may be preformed on the sections. The sections are welded together and the ring elements removed. The inner surfaces may then be provided with corrosion resistant layer 17 of oustenitic material which is sprayed or welded on. A pump (Fig. 1, not shown) comprises impeller (203) secured on shaft (202) by a nut (204) and inserted into the casing through the connection opening, a diffuser (201), and a pipe (205) which extends between the inlet and the front of the impeller.