▶ Demo
🎓 Engineering Learning Studio

Plumbing Engineering StudioUPC / IPC · Domestic Water · DWV Drainage · Fixture Units · Backflow Prevention

A complete learning environment for plumbing design professionals — from domestic water and DWV design tools and 3D building walkthroughs to interactive simulators, code references, and engineering calculation worksheets.

UPC / IPCDomestic WaterDWV DrainageFixture UnitsBackflow PreventionGrease Interceptors
Start here
📖Studio Overview🗺️Interactive System Map
🎓

Applied Plumbing Engineering Professional Program

25

Applied Plumbing Engineering Professional Program

Premium Content

Design real domestic water, DWV, venting, storm drainage, and specialty plumbing systems — fixture units, pipe sizing, hot water systems, backflow prevention, medical gas, and plumbing codes (UPC/IPC). 17 core modules, 5 complete real-project design packages (multi-family residential, hospital medical gas, commercial office restroom core, restaurant grease waste, high-rise domestic water riser), a 12-template documentation kit, and a certificate of completion. One-time purchase, no account required.

Explore the Full Curriculum →
📚

Knowledge Articles

20
🛢️
Hydromechanical vs. Gravity Grease Interceptors: Which One Applies
7 min read
📐
The PDI G-101 Drainage-Load Factor: Why It Is 0.75, Not 1.0
6 min read
The 25% Rule: Why Grease Interceptors Need Pumping Before They Are Full
6 min read
🍽️
Meals Served vs. Fixture Count: Two Different Ways to Size the Same Problem
6 min read
⚖️
FOG Ordinances: Why Municipalities Regulate Grease So Strictly
6 min read
🚰
What Is Plumbing Engineering? A Complete Overview
8 min read
📋
IPC vs UPC: Navigating Plumbing Codes
12 min read
🚿
Sanitary Drainage, Traps, and Venting Systems
14 min read
💧
Domestic Water Supply System Design
14 min read
🌡️
Water Heater Selection and Sizing
13 min read
🍳
Grease Interceptor Design and Sizing
10 min read
🔒
Backflow Prevention and Cross-Connection Control
11 min read
🌧️
Storm Drainage Systems: Roof, Site, and Siphonic Design
11 min read
🏥
Medical Gas Systems Design per NFPA 99
13 min read
🪣
Private Water Wells & Septic System Design
13 min read
♻️
Greywater & Rainwater Reuse Systems
12 min read
🧪
Plumbing System Testing, Disinfection & Commissioning
12 min read
🗺️
Plumbing System Design: A Complete Workflow Guide
9 min read
🏢
Apartment Plumbing Design: A Multi-Family Sample Project
10 min read
🚰
Plumbing Terminology Glossary: 55 Essential Terms Explained
13 min read

Frequently Asked Questions

How do you become a master plumber?

You generally complete a ~4–5 year apprenticeship (~7,500–8,000 hours plus classroom), pass the Journeyman Plumber exam, gain several years of licensed journeyman experience, then pass the Master Plumber exam. Requirements vary by state and locality.

Are plumbing license exams open book?

Most journeyman and master plumbing exams are open-book using the adopted plumbing code (UPC or IPC) and state amendments. They are computer-based and time-pressured, so fast code lookup matters.

What certification do I need to install medical gas piping?

Medical gas installation requires ASSE 6010 (installer) certification, with inspection/verification covered by ASSE 6020/6030; the work follows NFPA 99 and requires brazing qualification. It is a specialty layered on a plumbing/pipefitting background.

What is a backflow tester certification?

A Backflow Prevention Assembly Tester certification (commonly ASSE 5110) certifies you to test and certify backflow-prevention assemblies. It involves an approved course plus written and hands-on practical exams, and is often required to perform tests for water utilities.

💡

Concept Explainers

12
💥
Water Hammer — Why Stopping Flow Can Sound Like a Gunshot
Concept Explainer

A solenoid or check valve slams shut in milliseconds and a fast-moving column of water has nowhere to go. Illustrated look at the pressure spike that results, and why an air-chamber arrestor tames it.

Hydraulic ShockJoukowsky EffectPressure Surge
Explain This →
🔄
Backsiphonage vs. Backpressure — Two Opposite Ways Backflow Happens
Concept Explainer

A vacuum pulling contaminated water backward is not the same failure as a boiler pushing it backward — and a device that stops one often does nothing against the other. Illustrated side-by-side of both mechanisms.

Cross-ConnectionBackflow PreventionRPZ vs. AVB
Explain This →
⛰️
Gravity vs. Pressure Sewer Systems — Why Some Neighborhoods Need a Pump at Every House
Concept Explainer

One relies on nothing but a continuously sloping pipe; the other puts a grinder pump on every lot. Illustrated look at why terrain — not one method being 'better' — decides which sewer system a neighborhood gets.

Gravity SewerGrinder PumpLow-Pressure Sewer
Explain This →
🚰
Air Gap vs. Mechanical Backflow Preventer — The Only Truly Fail-Safe Cross-Connection Control
Concept Explainer

An air gap has nothing that can fail because it isn't connected to anything at all; an RPZ assembly stays in-line under pressure but depends on springs, seals, and discs staying in good working condition. Illustrated look at both prevention approaches and why codes require each at different hazard levels.

Air GapRPZ AssemblyCross-Connection Control
Explain This →
🌬️
Individual, Common & Wet Venting — Three Different Ways to Keep a Trap Seal From Being Siphoned Away
Concept Explainer

Every trap can lose its water seal to the vacuum created by its own draining fixture. Illustrated look at the three code-recognized venting methods that stop that from happening — and why they aren't interchangeable design choices.

Trap SealWet VentDWV Venting
Explain This →
🌧️
Combined vs. Separate Sewer Systems — Why Mixing Storm and Sanitary Flow Causes Real Overflow Problems
Concept Explainer

One pipe carrying both sewage and rain runoff works fine in dry weather — until a heavy storm pushes the combined volume past capacity and the system is forced to overflow untreated into a river. Illustrated look at why separate sanitary and storm sewers don't have this failure mode at all.

Combined Sewer OverflowCSOStorm vs. Sanitary
Explain This →
💧
Hard vs. Soft Water — Why Softening Trades One Mineral Problem for a Sodium Tradeoff
Concept Explainer

Hard water's dissolved calcium and magnesium cause real scale buildup and soap-effectiveness problems — but ion-exchange softening fixes that by adding sodium, a genuine chemical tradeoff, not a free upgrade. Illustrated look at both, and why many installs bypass softening for an exterior spigot.

Ion ExchangeWater HardnessSoftener Bypass
Explain This →
🕳️
Direct vs. Indirect Waste Connections
Concept Explainer

Why some fixtures and equipment must never be directly piped to the drain system — an air gap makes drainage-system backup contamination physically impossible, regardless of downstream blockage severity.

Indirect WasteAir GapContamination Prevention
Explain This →
🏢
Vent Stack vs. Stack Vent
Concept Explainer

Same two words, reversed — but a stack vent is just the soil stack itself extended through the roof, while a vent stack is a genuinely separate, dedicated pipe running alongside it. Illustrated side-by-side of both configurations and why taller systems need the dedicated pipe.

Stack VentingRelief VentDWV System
Explain This →
📈
Fixture Units vs. Flow Rate (GPM) — Why a WSFU Isn't a Literal Flow Rate
Concept Explainer

A Water Supply Fixture Unit is a demand-probability weight, not a GPM figure — which is exactly why converting a building's total WSFU count into design GPM needs Hunter's Curve, not a fixed multiplier. Illustrated look at the nonlinear curve and why doubling WSFU never doubles the required flow.

WSFUHunter's CurveDemand Flow
Explain This →
🧰
PEX vs. Copper vs. CPVC — Choosing a Water Supply Pipe Material
Concept Explainer

Three genuinely different jointing methods — crimp/expansion, sweat-solder, and solvent-weld — and three genuinely different limit curves. Illustrated look at why the 'right' pipe material is a per-run decision, not a universal winner.

PEXCopperCPVC
Explain This →
🔥
Tankless vs. Tank Water Heaters — On-Demand Heat Exchange vs. Stored Volume
Concept Explainer

'Endless hot water' is real, right up until simultaneous fixture demand exceeds the unit's flow-rate ceiling. Illustrated look at why a tankless heater and a tank heater run out of two completely different resources.

Tankless GPMFirst Hour RatingRecovery Rate
Explain This →
📜

Plumbing License & Certification Exam Prep

9/9 Live
LIVE
Exam Prep Overview — Plumbing Systems

Plumbing is a licensed trade with specialty certifications layered on top. This overview covers the journeyman → master → contractor license ladder, plus medical-gas, backflow-tester and plumbing-design credentials.

OverviewRequirementsExam Strategies
Premium Content
Journeyman Plumber License — Practice Exam

Journeyman Plumber prep: plumbing code (UPC/IPC), DWV & venting, water-supply sizing, fixtures and gas piping.

UPC/IPCDWVCode Lookup
🔒 View
Premium Content
Journeyman Plumber License — Extended Practice Exam

Your state licensing exam is open-book but timed, so speed and code fluency both matter. This adds 150 more original questions on UPC/IPC code lookup, DWV and venting, water-supply sizing, fixtures and gas piping to sharpen both. Finish the exam and get an instant pass/fail score, a topic-by-topic breakdown showing exactly which code areas need more review, and a full question-by-question review with a written explanation for every question — including the ones you missed. Instant online access after purchase, good for 90 days.

150 New QuestionsCode-Area BreakdownFull Answer Review
🔒 View
Premium Content
Master Plumber License — Practice Exam

Master Plumber prep: advanced code application, system design/sizing, plan review and cross-connection control.

MasterSystem DesignPlan Review
🔒 View
Premium Content
Master Plumber License — Extended Practice Exam

Master-level exams push further into design and supervision, so this adds 150 more original questions on advanced code application, system design and sizing, plan review, and cross-connection control. When you finish, you get an instant pass/fail score, a topic-by-topic breakdown showing exactly which areas need more study before your state exam, and a full question-by-question review with a written explanation for every question — including the ones you missed. Instant online access after purchase, good for 90 days.

150 New QuestionsTopic BreakdownFull Answer Review
🔒 View
Premium Content
Plumbing Contractor License — Practice Exam

Plumbing Contractor prep: the trade exam plus business & law — estimating, contracts, liens and bonding.

ContractorBusiness & LawPermits
🔒 View
Premium Content
Medical Gas Installer / Inspector (ASSE 6010 / 6020) — Practice Exam

Medical Gas (ASSE 6010/6020) prep: NFPA 99 med-gas piping, brazing, verification, zone valves and purity testing.

ASSE 6010NFPA 99Medical Gas
🔒 View
Premium Content
Backflow Prevention Assembly Tester (ASSE 5110) — Practice Exam

Backflow Tester (ASSE 5110) prep: cross-connection control, assembly types (RP/DC/PVB) and field test procedures.

ASSE 5110BackflowCross-Connection
🔒 View
Premium Content
Certified in Plumbing Design (CPD) / PE Mechanical — Practice Exam

CPD / PE Mechanical prep: plumbing-system design — water supply/drainage, fixture units, storm and gas systems.

ASPE CPDPEPlumbing Design
🔒 View
🎮

Simulators

4
Plumbing Demand Flow SimulatorPremium Content

Simulate domestic water demand for a multi-story building using the IPC Hunter's Curve probability method. Configure building type, number of floors, and fixture types and counts per floor. The simulator aggregates WSFU floor-by-floor, converts to peak design GPM, sizes the service entrance pipe, and calculates static pressure loss due to elevation. A results panel shows whether available street pressure is sufficient or whether a booster pump is needed.

Hunter's CurveWSFUIPCBooster Pump
🔒 View
Grease Interceptor Sizing SimulatorPremium Content

PDI G-101 hydromechanical grease interceptor sizing and gravity interceptor (GGI) volume calculator. Input fixture flow rates, grease retention factor, and pumping frequency to size the right interceptor for a commercial kitchen.

PDI G-101FOGHGIGGI
🔒 View
Backflow Preventer Selection GuidePremium Content

Interactive decision tree for selecting the correct backflow prevention device (air gap, RPZ, DCVA, PVB, SCVB) based on hazard degree (high vs. low), backflow type (back-pressure vs. back-siphonage), and application type.

RPZDCVACross-ConnectionBackflow
🔒 View
Building Plumbing 3D VisualizerPremium Content

Interactive 3D walkthrough of a 2-story building’s plumbing systems. Explore cold/hot water supply, DWV drainage, the main stack, vent stack roof penetration, fixtures, traps, and cleanouts, with IPC references and an animated water-flow trace from source to fixture and fixture to sewer.

3D InteractiveSupply & DWVIPCVent StackFlow Animation
🔒 View
🧮

Engineering Calculations

3
Fixture Unit Counter (WSFU & DFU)Premium Content

Tally Water Supply Fixture Units and Drainage Fixture Units for 12 fixture types per IPC tables.

WSFUDFUIPC
🔒 View
Pipe Sizing Calculator (IPC)Premium Content

Size cold and hot water supply pipes from WSFU using Hunter's Curve demand flow and velocity limits.

IPCHunter's CurveGPM
🔒 View
Sprinkler HydraulicsPremium Content

NFPA 13 density/area method for 6 hazard classes. Total demand GPM, hose allowance, and residual pressure.

NFPA 13GPMDensity/Area
🔒 View
📖

Interactive Readers

2
🔧
Plumbing Systems Design Reference
Premium Content
11 sections · Interactive Reader

Interactive 11-section plumbing reference covering water supply sizing (Hunter's method), sanitary drainage (IPC/UPC), vent systems (trap-to-vent distances), water heaters (legionella prevention), backflow prevention (RPZ/DCVA), roof drainage, medical gas (NFPA 99), and fuel gas (NFPA 54/IFGC). First 3 free to preview.

Hunter's MethodSanitary DrainageBackflow RPZNFPA 99 Med Gas
🔒 View
🚰
Plumbing Systems — Illustrated Guide
Premium Content
23 sections · Interactive Reader

Interactive 23-section illustrated guide covering WSFU pipe sizing and Hunter's Curve, DWV and roof drainage design, hot water recirculation and storage sizing, commercial and multi-story riser design, and facility-specific plumbing plans through inspection and commissioning. First 3 free to preview.

WSFU SizingDWV DesignHot Water RecircCommercial Risers
🔒 View