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Pipe Database Design Program
Pipe Database Algorithms
The Pipe Database contains arrays of nominal pipe sizes, their actual outer diameters and the minimum wall thicknesses based on Pipe Schedules 10, 30, 40, 80, 120,160 and Pipe Standard Dimension Ratios 17, 21, 26,32.5, and 41. From this information an array of available pipe sizes can be constructed given the Pipe Specification, which is the Pipe Schedule or SDR selected in the Master Program. There are a few programs written to return inner and outer diameters of pipes for certain inputs.
The pipe database was updated to limit which pipe sizes in the pipe database were used. For instance, although we found information from manufacturers about 3 inch pipes they are uncommon and are unlikely to be available for use in Honduras. In the future the pipes available for use could be chosen by the user instead of us.
The pipe database also includes many functions that differ only in their ability to return a single column array for inner diameters or a double column array with inner diameters and nominal pipe sizes. Most team members chose to use only those that returned a single column since there was preexisting code that required an available pipe size array of this size. Once an inner diameter is chosen, another function was written to find the nominal pipe size. In the future the use of these two types of functions can be evaluated and those that are not needed can be removed.
Pipe Sizes
A pipe design function was created so that all pipes could be designed quickly and corrected. In order to find the proper diameter the program iteratively solves for the flow that can fit through a pipe of a given diameter with the given head loss until a large enough diameter is found in the pipe database.
The inputs of this function are the maximum flow of the plant (Q plant ), the pipe specification of available dimensions (PipeSpecification), the maximum head loss ( h lmax), the sum of all the individual head loss coefficients of elbows, tees, valves, expansions and contractions (K sum) and the length of the pipe (L pipe).
The Q plant , and L pipe are assumed design values.
The PipeSpecification calls the Pipe Database, please refer to the Pipe Database section.
K sum values equal to the number of elbows, tees, valves, expansions and contractions multiplied by their corresponding K ~ values~. All corresponding K values are given in the Basis of Design tab.
h lmax values calculated using the following set of equations.
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Re = Reynolds Number, to determine if flow is turbulent or laminar
Q = Flow Rate
D = Pipe Diameter
ν = Kinematic viscosity of water
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f = Friction factor, equation for either turbulent or laminar flow
ε = Roughness factor of PVC
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h = Major head loss
The outputs of this function are nominal pipe diameters. The pipe diameter is referenced from the pipe database.
Description
Arrays: The pipe database needs to store the many parameters of the pipes available to build the plants.
- Pipesizes: This array holds the nominal pipe size, in inches, and actual average outer diameter.
- MinWallThicknesses: This array holds the values for the wall thicknesses for each different PipeSpecification and nominal pipe size.
- Pipe Fittings: This array holds the nominal pipe size, in inches, the elbow radius, tee length, socket depth, cap diameter, and cap height for each size of pipe. It is used to get information to draw tees, crosses, elbows, and caps in the plant.
Functions
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