Design of piping systems: Steam & Condensate

Install a water separator after the boiler to dry steam, and install float or thermodynamic steam traps at user points and risers to drain condensate into the condensate network.

Install filters before each steam trap, regulating valve, and reducing valve, using perforated (0.8–1.6 mm) or mesh (100 mesh) inserts, and mount horizontally to prevent condensate buildup and water hammer.

Explore how air vents and vacuum breakers keep steam free of air, prevent vacuum, and improve heat transfer and efficiency by ensuring reliable condensate removal.

Regulating valves are externally controlled with pneumatic actuators, using pressure or temperature feedback to modulate flow; include globe, ball, and butterfly types with on/off and modulating modes.

Explore how pressure reducers automatically regulate outlet pressure despite varying inlet pressure, using direct acting and pilot acting types with internal or external sensing.

Learn how pressure reduction of steam from 6 bar to 3 bar creates superheated or desaturated steam, and how drying, water content, and energy balance affect temperature.

Size a steam collector from the boiler output, cap velocity at 10 m/s, and use a steam trap to drain condensate and isolate the collector, with top drainage.

Size up pipes using a pressure drop calculation with Dusty Whaleback formula and Duffy Weisbach equation, including fittings and bends, using Moody diagram or VBA to estimate friction factor.

Size condensate pipes by considering rising and draining segments around the condensate head, ensuring condensate from user points drains into the head with proper design velocities and steam-trap selection.

Size condensate lines from steam lines by calculating steam consumption with an Excel sheet or empirical design, and set condensate trap trip heights using 200 mm max or half diameter.

Size condensate headers so the header surface is at least the sum of all branch sections, then place branches from the top to prevent flooding, back pressure, and water hammer.

Estimate the heat exchanger's installed power from water flow, cp 4.2 kJ/kgK, and a 15-70 °C temperature rise, then size the exchanger using U 2.5 kW/m²K and the log mean temperature difference with margins to achieve a 963 kW design power for steam and condensate.

Calculate heat exchanger power and steam flow by dividing by latent heat to obtain steam mass, then apply velocity design to select a pipe size and account for pressure variations.

Calculate pressure variations in a heat exchanger from steam and water temperatures at 100% and 10% duties. Use latent heat and the saturated steam–water relationship to infer pressures.

Evaluate lines after the control valve for steam and condensate; justify a 60 m/s velocity and 4-inch line to minimize condensation and suit a short run to the heat exchanger.

Compare control valve types—equal percentage, fast opening, and linear—and select from catalogs to meet Cv and rangeability. Consider parallel valves to widen the range while avoiding hunting and overlap.

Condensate sizing teaches calculating steam drop pressure using elevation pressure and a worst-case five-meter water column to select a 1 1/2 inch ft 14 schedule 40 condensate line.

This lecture covers condensate line sizing after the steam trip, balancing max flow and duty with cost-effective pipe sizes, and cooling condensate with a section after the steam trap.

Calculate heat exchanger stalling due to condensate flooding by comparing upstream and downstream pressures, identify the start point when they equal, and apply vacuum breakers, float traps, or condensate pumps.

Explore an Excel calculation sheet that sizes heat exchangers, with green input cells and sample data: 963 kW, 3 to 4 inch pipes, and varying duty.

Analyze failure flow in piping systems to size a safety valve, considering two failures: faulty pressure control valve and supply pressure drop, and identify critical versus non-critical flow.

Explore safety preliminary selection for steam systems by reading PSV capacity tables, choosing valves with or without lifting devices, and selecting a 20 size based on operating pressure.

Size vent lines downstream of the PSV to manage pressure drop, using sectional calculations with friction factor and pipe diameter, and install boot screens to prevent condensate buildup.

design a direct injection heating system using steam and condensate, calculating required power and steam flow. Then size the control valve and injection nozzles with temperature feedback.

Assess direct injection in steam systems by validating mass flow and design acceptability, then size upstream and downstream control valves to finalize an integrated piping network with automatic drainage.

Reach the end of the course on design of piping systems and prepare for future topics as you apply lessons to your plant, advancing as a process or project engineer.