Articles

Modeling a Strainer

A strainer is a device installed in a piping system which provides a means for mechanically removing foreign particles from a flowing fluid. Most strained particles are in the size range between 40 micron and 1 inch, and are typically removed by using a perforated, mesh, or wedge wire straining element. For some processes, the particles are undesirable and the purpose of straining these particulates is to protect downstream mechanical equipment such as pumps, heat exchangers, control valves, flow meters and spray nozzles from the detrimental effects of flow debris. It also serves to prevent this debris from ending up in the final product in some manufacturing cases. Other processes may require straining because the particles, not the process fluids, are the desired product.
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Understanding the Distinction Between Total, Static and Dynamic Pressure

When discussing a piping system, the term "pressure" is often used to describe a key fluid property that plays an important role in the operation of equipment like pumps, control valves, tanks and vessels and other devices. However, like many terms used in engineering, there are nuances in meaning that must be taken into account to avoid miscommunication, confusion and costly mistakes. Quite often, key qualifiers that distinguish between total pressure, static pressure and dynamic pressure are not used. Sometimes the distinction is important, just as the difference between mass flow rate and volumetric flow rate must be made to be concise when discussing flow rate.
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ESI Develops Crude Oil Fluid Parameters to Aid in Hydraulic Analysis

To assist our customers in the design, evaluation and troubleshooting of crude oil piping systems, Engineered Software, Inc. has developed some representative crude oil fluid parameters. Since crudes are generally described as being light, medium or heavy, using an industry recognized term to define the different representative fluids along this vector makes the most sense. The American Petroleum Institute (API) has defined API gravity as the indicator of crude “heaviness” and it is a function of the fluid’s density relative to water. The higher the API gravity (measured in degrees), the less dense the fluid. Most pumpable crudes fall in the range of 15 to 45 API degrees, so providing parameters for representative fluids in 5 API degree steps across this range was deemed to be of sufficient granularity.
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Three Ways to Accurately Model Tee Fittings Using PIPE-FLO®

Users often inquire about the correct way to account for the losses through a Tee fitting. PIPE-FLO® Professional utilizes the fitting methods described in the Crane Technical Paper 410: Flow of Fluids Through Valves, Fittings and Pipes. The TP-410 provides just two L/D values for Tees that are used to calculate the K resistance values; 20 for Flow Thru Run and 60 for Flow Thru Branch. The TP-410 offers no further information about how to apply these values, as that is all of the information needed to solve for a single flow path. However, confusion comes about when trying to determine how to incorporate these values into a PIPE-FLO® model where we are solving multiple paths simultaneously. For some applications, the losses through Tees are insignificant and for other applications the TP-410 method may be too general, and more geometry specific methods are desirable. Ultimately, the choice of method is based in the engineering judgement of the user, but we will cover several options to model these Tees in PIPE-FLO®.
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Accurately Modeling Pulp and Paper Piping Systems With the PIPE-FLO® Stock Module

Accurately modeling a pulp and paper slurry piping system can be difficult without the proper tools and equations. This difficulty is caused because slurries do not act in the same manner that water in pipelines does. This phenomenon is known as Drag Reduction. In the upcoming release of PIPE-FLO® Professional, users can accurately model stock fluid using the method described below.
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PUMP-FLO® Connect Optimizes Pump Selection with New Multiple Operating Points & SRC Feature

With PUMP-FLO® Connect, users have the option of specifying additional operating points and system resistance curves to be displayed in the pump’s graph windows. This includes operating points with different static and total heads, or even with different flows. Data inserted in the operating points interface is entirely up to the user. While these points are not used as criteria for pump selection, the standard warning messages will apply if these points are outside of the pump’s limits.
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When Should You Use the HSS vs the HX 2-Pipe Device?

Both of the new devices added in PIPE-FLO® Professional version 15 can model real-world processes that facilitate sensible heat transfer in flowing fluids. The heat source/sink device is used to model heat transferred into or out of a single fluid, whereas the heat exchanger 2-pipe device is used to model sensible heat transfer between two fluids. Both devices model the hydraulic performance of only one side of a heat exchanger.
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