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Design of Soil Vapor Extraction Systems
Published in Jimmy H.C. Wong, Chin Hong Lim, Greg L. Nolen, Design of Remediation Systems, 2020
Jimmy H.C. Wong, Chin Hong Lim, Greg L. Nolen
Where the vapor abatement system requires supplementary fuel, natural gas, if available, is usually provided. Natural gas supplied to most residences and small businesses comes at a low pressure, approximately 0.3 psi or 8 in. WC. Typically, a thermal oxidizer requires a medium pressure of approximately 2 psi. The design engineer’s first duty is to inquire with the local gas company if the required pressure is available at the specific location. Piping from the service meter to the unit will have to be included in the system. The size and material for the piping is specified in the Uniform Plumbing Code (UPC; 1994), Chapter 12: Fuel Gas Piping.
Conventional Waste Disposal Systems
Published in Richard J. Perkins, Onsite Wastewater Disposal, 1989
Gravel must be added to support the sides of the trench and to provide space to hold the slugs of wastewater that come from the septic tank. Minimum depth of fill with gravel is 6 in. below the distribution pipe according to the Manual of Septic Tank Practice and 12 in. according to the Uniform Plumbing Code. Again, lacking any requirements, you should decide whether to go with more gravel for a longer trench life or less gravel for a less expensive system. In general, the extra gravel is cost-effective.
A novel dynamic hydrant flushing framework facilitated by categorizing contamination events
Published in Urban Water Journal, 2020
Mohammad Ali Khaksar Fasaee, Mohammad Reza Nikoo, Parnian Hashempour Bakhtiari, Shahryar Monghasemi, Mojtaba Sadegh
Upon sensor activation, the contamination events must be flushed from the WDS in the shortest time to minimize the impact. Flushing the system, however, should follow certain guidelines. The water pressure at the discharging hydrant should be, for instance, at least 20 psi in order to ensure consistent performance of the hydrants (Uniform plumbing code 2006). For this reason, a small demand (1 gpm) is applied to the potential hydrant nodes and the EPANET simulation model is executed to measure the nodes’ pressure. Nodes with pressure less than the allowed limit will be omitted as non-eligible and the simulation repeats until the remaining nodes satisfy the pressure limit. This preprocessing procedure can also reduce the optimization decision variables, which in turn contributes to lowering the computational time.