GB1464116A - Pump support - Google Patents

Abstract

1464116 Machine supports; hydraulic dampers COMBUSTION ENG Inc 19 Aug 1974 [22 Aug 1973] 36429/74 Headings F2X and F2S A support arrangement for a pump, in particular the coolant pump of a nuclear power plant, which permits movement of the pump owing to thermal effects and can withstand sudden shock loading, includes four vertical posts 26 beneath the pump 20 pivotally attached at their upper ends to the pump 20 and at their lower ends to a stationary structure (not shown) which is designed to withstand earthquake tremors, and four horizontal posts 28, 30 pivotally attached at one of their ends to the pump 20 and at their opposite ends to the stationary structure. Vertical posts 26 and horizontal posts 28 are pivotally attached to a downwardly extending skirt 24 integral with the pump motor housing 23 and horizontal posts 30 are pivotally attached to the pump motor housing 23. The thermal movement of the pump 20, due to the reactor vessel (10) (Fig. 1, not shown) becoming hot as the plant is initially started, is generally in a radial direction of the vessel (10) and thus the pump 20 will move substantially in the direction of arrow 22, and the four horizontal posts 28, 30 extend in a direction transverse of the arrow 22. A pair of snubbers 32 extending in the direction of arrow 22 are pivotally attached to both the motor housing 23 and the stationary structure. The pivotal attachments may comprise spherical bearings (34) (Fig. 3, not shown). As shown in Fig. 4, each snubber 32 comprises a cylinder 46 containing a piston 42, the rod 40 of which is pivotally attached to the motor housing 23 while the cylinder 36 is pivotally attached by a rod 44 with the stationary structure. Hydraulic lines 58, 60 connected to the opposite ends of the cylinder 46 are also in fluid communication with a chamber 48. A pair of valves 50, 52 are biased away from their respective valve seats 53, 55 by means of a spring 54. The system is completely filled with a liquid. Thus, when the pump 20 is subjected to slow movement caused by thermal growth, liquid can flow from one side of piston 42 to the other through chamber 48. In the event the pump 20 is subjected to abrupt forces, as from an earthquake, tending to move the piston 42 one way or the other, the sudden surge of pressure in pipe 58 or 60 will cause valve 50 or 52 immediately to close by overcoming the force of spring 54. In either event, the snubber 32 becomes a rigid supporting member. If the earth tremors exert forces on the pump 20 in vertical directions or other horizontal directions, either the vertical posts 26 or the horizontal posts 28, 30 serve to hold the pump 20 securely in place. A reservoir 56 in communication with the chamber 48 serves to compensate for the difference in volume on the respective sides of piston 42 because of the presence of rod 40.