A complete engineering resource for mechanical systems design professionals. Covers plumbing design per the IPC, domestic water and sanitary drainage pipe sizing, hydronic heating system design, fire sprinkler hydraulics per NFPA 13, compressed air and medical gas systems per NFPA 99, and mechanical equipment room layout.
Built for mechanical engineers, plumbing designers, fire protection engineers, and PE Mechanical exam candidates. Covers the plumbing, hydronic, and fire suppression calculations tested on the PE Mechanical exam and used in construction document production.
Interactive Darcy-Weisbach pipe flow simulator. Select pipe material (copper Type L/K, Schedule 40/80 steel, PVC, CPVC), nominal diameter, flow rate, and run length. The simulator calculates Reynolds number, Moody friction factor (laminar, transition, or turbulent regime), and friction head loss per 100 ft. Add fittings (elbows, tees, gate/globe/ball valves, reducers) via K-factor method to compute total minor losses. A real-time comparison table shows pressure drop and velocity across all standard pipe sizes simultaneously — so you can instantly see which size hits your target velocity (2–4 fps recommended) and stays within your pressure budget.
Step-through NFPA 13 hydraulic calculation for a branch-line sprinkler system using the density/area method. Configure hazard occupancy (Light, OH-1, OH-2, EH-1, EH-2), design area, density (gpm/sq ft), system pressure, and pipe material. The simulator walks through the most-remote-area hydraulic calc: starts at the most demanding sprinkler, applies K-factor flow at each head (Q = K√P), accumulates flow and pressure loss along the branch line and cross main using the Hazen-Williams equation, adds hose stream allowance per occupancy, and plots the final system demand point (GPM @ PSI) against a water supply curve. Pass/fail verdict against available system pressure.
Simulate a closed-loop hydronic heating system end-to-end. Configure boiler output (BTUH), supply and return water temperatures (ΔT), and terminal unit type (fin-tube baseboard, fan coil, radiant panel). The simulator calculates system flow rate (GPM = BTUH ÷ (500 × ΔT)), sizes the circulating pump (TDH from pipe losses and fittings), and sizes the expansion tank per ASME. An animated loop diagram shows water temperature dropping from supply (hot/red) to return (cool/blue) as it releases heat at each terminal unit. Real-time checks flag minimum velocity (0.5 fps), maximum velocity (4 fps), and pump operating point against a simplified system curve.
Interactive steam distribution simulator covering low-pressure (≤15 psi), medium-pressure (15–100 psi), and high-pressure (100–300 psi) systems. Configure boiler output (lb/hr or BTUH), operating pressure, and a 4-branch distribution layout. The simulator sizes supply mains and branch pipes from ASME steam tables, calculates pressure drop and velocity at each segment, and checks steam velocity limits (4,000–6,000 fpm for supply, 1,500–2,500 fpm for wet return). An animated one-line diagram shows steam flowing from the boiler header through supply mains, through steam traps at each branch takeoff, and returning as condensate via gravity return or condensate pump. Steam trap type selection (float & thermostatic, thermodynamic, inverted bucket) with load calculation per branch.
Visualize hydraulic transients (water hammer) using the Joukowsky equation: ΔP = ρ·a·ΔV, where wave speed a varies by pipe material (copper ≈ 4,400 fps, steel ≈ 4,860 fps, PVC ≈ 1,400 fps, HDPE ≈ 1,200 fps). Configure pipe material, diameter, flow velocity, pipe length, and valve closure time. An animated SVG shows the pressure wave propagating from the closed valve back to the source. The simulator calculates peak surge pressure (psi), compares it to the pipe pressure rating, determines whether closure is "instantaneous" (t_close < 2L/a — the critical threshold), calculates the wave return period (2L/a), and recommends a pressure relief valve set pressure or surge arrester pre-charge pressure to protect the system.
Simulate domestic water demand for a multi-story building using the IPC Hunter's Curve probability method. Configure building type (office, hotel, hospital, multifamily residential), number of floors (up to 20), and fixture types and counts per floor. The simulator aggregates Water Supply Fixture Units (WSFU) floor-by-floor from the top down, converts to peak design GPM using Hunter's Curve, sizes the service entrance pipe, and calculates static pressure loss due to elevation (0.433 psi/ft of height). A results panel shows whether available street pressure (configurable from 40–120 psi) is sufficient to reach the top floor with required residual pressure, or whether a booster pump is needed — and if so, calculates required pump head (ft) and minimum pressure at the pump discharge.
IPC Table 604.3 pipe sizing from water supply fixture units (WSFU). Hunter's curve GPM estimate, velocity check, and recommended pipe diameter.
Tally WSFU and DFU for 12 fixture types. Running totals for sizing water supply and drainage systems per IPC.
Brake horsepower from GPM, TDH, SG, and pump efficiency. Selects next standard NEMA motor size. Pipe velocity check included.
LMTD method for shell & tube, plate, gasketed plate, and brazed plate HX. Outputs LMTD, required area, and U-value range.
Capacity lookup table for low, medium, and high pressure steam. Selects pipe size from lb/hr demand per ASME/industry tables.
Darcy-Weisbach pressure drop for compressed air. Comparison table across pipe sizes with pass/fail velocity check.
ASME expansion tank sizing for closed hydronic systems. Expansion factor, system volume, and next standard tank size.
NFPA 13 density/area method for 6 hazard classes. Total demand GPM, hose allowance, and residual pressure requirement.
Convert between HP, kW, and torque at any RPM. Quick-select common motor speeds. Motor sizing with 10% service factor.
Reynolds number and velocity check for 6 meter types: turbine, vortex, magnetic, ultrasonic, orifice plate, and Coriolis.
Mechanical engineers are licensed through the PE system. This overview covers the FE Mechanical and the three NCEES PE Mechanical depth exams — Machine Design & Materials, Thermal & Fluids Systems, and HVAC & Refrigeration — and how to choose between them.
FE Mechanical prep: thermodynamics, fluids, heat transfer, mechanics of materials, dynamics and machine design.
PE Mechanical: Machine Design & Materials prep: stress, fatigue, materials, fasteners, bearings/gears and vibration.
PE Mechanical: Thermal & Fluids prep: cycles, fluid mechanics, heat transfer, pumps/turbomachinery and piping.
PE Mechanical: HVAC & Refrigeration prep: psychrometrics, loads, air/hydronic distribution and refrigeration.
Interactive 13-section PE Mechanical exam reference covering thermodynamics, fluid mechanics, heat transfer, machine elements, dynamics, materials, HVAC, pressure vessels, and turbomachinery.