Discussion of “Effect of Pipe Size and Location on Water-Main Head Loss in Water Distribution Systems” by Saeed Hashemi, Yves Filion, Vanessa Speight, and Andrew Long

ABSTRACT The design of water distribution systems includes, above all, the determination of the pipe size that meets the requirements of the system and brings reduced annual costs of installation and operation. Among the existing methodologies for the economic pipe diameter determination, Bresse’s equation is still common among designers. This work aims to analyze the efficiency of Bresse’s equation, the MBPW and the MLVPC, comparing them with the MREC. We recommend that the designers do not use the MBPW and the MLVPC. When referring to water distribution systems of small size, it is possible to use the equation of Bresse, as long as it is used with a proper value for its coefficient k. For HDPE, we propose k = 1.17 or k = 1.18. For PVC DEFOFO and GFRP, we suggest the range of 1.19 to 1.23 and 1.29 to 1.32, respectively. Regarding the water distribution systems of bigger dimensions, we recommend the use of MREC as the methodology for the economic pipe diameter determination, due to the impossibility of finding an appropriate value for the Bresse’s equation coefficient.

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Development of Practical Design Approaches for Water Distribution Systems

Applied Sciences ◽

10.3390/app9235117 ◽

2019 ◽

Vol 9 (23) ◽

pp. 5117

Author(s):

Young Hwan Choi ◽

Ho Min Lee ◽

Jiho Choi ◽

Do Guen Yoo ◽

Joong Hoon Kim

Keyword(s):

Optimal Design ◽

Distribution Systems ◽

Water Distribution ◽

Design Method ◽

Water Distribution Systems ◽

Computation Time ◽

Practical Design ◽

Previous Design ◽

Design Factors ◽

Pipe Size

The optimal design of water distribution systems (WDSs) should be economical, consider practical field applicability, and satisfy hydraulic constraints such as nodal pressure and flow velocity. However, the general optimal design of a WDSs approach using a metaheuristic algorithm was difficult to apply for achieving pipe size continuity at the confluence point. Although some studies developed the design approaches considering the pipe continuity, these approaches took many simulation times. For these reasons, this study improves the existing pipe continuity search method by reducing the computation time and enhancing the ability to handle pipe size continuity at complex joints that have more than three nodes. In addition to more practical WDSs designs, the approach considers various system design factors simultaneously in a multi-objective framework. To verify the proposed approach, the three well-known WDSs to apply WDS design problems are applied, and the results are compared with the previous design method, which used a pipe continuity research algorithm. This study can reduce the computation time by 87% and shows an ability to handle complex joints. Finally, the application of this practical design technique, which considers pipe continuity and multiple design factors, can reduce the gap between the theoretical design and the real world because it considers construction conditions and abnormal situations.

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