Junya KAWABATA
Business Development Division, Fluid Machinery and Systems Company
The model GSD close-coupled pump that applies the European standard EN733 to the pump section and the international standard IEC60034 to the motor section and connects them with a rigid coupling has been released. This product has met or exceeded the standards required by the pump efficiency regulations in each major country, and, since it does not require the centering work of the coupling, it is easy to handle as a part of the Model GS series. It is a product that can be widely distributed in each country.
Keywords: Close-coupled, Rigid coupling, Pump efficiency regulation
In 2015, EBARA Corporation (hereafter EBARA) launched the Model GS series high-efficiency pumps, which are long-coupled end-top centrifugal pumps for the global market, complying with European standard EN733. Since then, the Model GS series has continued to expand its product lineup to meet a variety of applications, from beverage to industrial use. The Model GS series pumps feature high efficiency and easy maintenance. In addition, to meet customer needs in the market for a more compact close-coupled pump that requires no centering work, EBARA developed the Model GSD close-coupled pump (Figure 1), which uses the main components of the GS series and has the pump section and the flange motor connected with a rigid coupling, and released it in April 2020.
Fig. 1 Model GSD close-coupled pump
This paper will provide an overview and introduce features of the Model GSD close-coupled pump.
The specifications of this product are shown in the table, and the selection charts are shown in Figures 2 and 3.
| Capacities | To 700 m3/min | ||
| Heads | To 150 m | ||
| Liquid temperature | －10 to 120 ℃ | ||
| Max.working pressure | 1.6 MPa | ||
| Construction | Casing | End suction top discharge | |
| Impeller | Closed, single suction type hydraulically balanced | ||
| Shaft seal | Rubber bellows mechanical seal (EN12756) | ||
| Materials | Casing | Cast iron | |
| Impeller | Cast iron or Bronze | ||
| Shaft | SUS420J2Q (Wetted part) | ||
| Applicable pump standard | EN733 | ||
| Applicable flange standard | EN PN16 (EN1092-2) | ||
| Rotation | Clockwise viewed from drive end | ||
| Paintings | Outer surface | Primer coating | Cationic electro-deposition painting |
| Final coating | Alkyd resin based enamel | ||
| Inner surface | Primer coating | Cationic electro-deposition painting | |
| Final coating | Non painting | ||
Fig. 2 Selection chart (4 poles)
Fig. 3 Selection chart (2 poles)
Fig. 4 Structural drawing
The casing, casing cover, and impeller of the Model GSD pump are the same as those of the GS series. Other main components are the shaft, bracket, and motor. The flange motor and pump are coupled with a bracket. The structural features are shown below. (1) The casing with end suction and feet allows inspection and replacement of the rotor without removal of the piping. (Back pull out design) (2) Since this is a close-coupled pump with a rigid coupling, no centering work is needed, and its compactness allows more installation space.
The casing and impeller are the same as those of the GS series, which was developed to minimize internal losses by using the latest technologies, such as computational fluid dynamics (CFD) analysis and the three-dimensional inverse method. As a result, this pump achieves the highest pump efficiency and easily meets pump efficiency regulations in enforce in Europe, China, and the United States. As shown in the CFD analysis results in Figure 5, the pump interior is designed to minimize losses, such as flow separation.
Fig. 5 CFD analysis results (example)
This pump is designed to meet the replacement demands of the global market, because the dimensions of the pump casing comply with European standard EN733, and an EN1092-2 PN16 flange is used.
Since the mechanical seal is EN12756 compliant, the pump can be selected depending on the availability of the mechanical seal in each region. The motor complies with European standard IEC60072-1, Japanese standard JIS-C-4213, and AS/NZ standard 1359.5 to meet major market requirements.
The pump section is designed to avoid the risk of human contact with the rotating parts, in accordance with the European Machinery Directive. In addition, it is possible to select CAC902, a lead-free material, for copper alloy parts, such as impellers and liner rings, to comply with European standard EN50581 (RoHS2).
In addition, a bracket protector is provided to ensure safety and prevent the human body from coming into contact with the rotating parts. The protector can be removed for maintenance or motor replacement to secure sufficient workspace. This allows motor replacement without disassembling the pump section.
With the addition of the Model GSD close-coupled pump to its lineup, the GS series is expected to be more widely used as its ability to meet the various needs of the global market broadens. In the future, there is an urgent need to comply with other major standards. For example, the development of motors conforming to NEMA standards for the North American market. Finally, I would like to express my deep gratitude to all the parties involved in the development of the GS series.