Issue No. 260・261〔New Products & New Techniques〕

High Efficiency GS Series Model GSD Close-Coupled Pump

Author

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

1. Introduction

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.

2.Specifications and construction

2-1. Specifications

The specifications of this product are shown in the table, and the selection charts are shown in Figures 2 and 3.

Table. Product specifications
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)

2-2 Structure

Figure 4 shows the product structure.

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.

3. Product features

3-1 High efficiency

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)

3-2 Compliant to international standards

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.

3-3 Safety

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.

4. Future development

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.