Plumbing System Design - Complete Professional Course

<h3>Learning Objectives</h3><ul><li>Understand the history and purpose of plumbing codes</li><li>Differentiate between IPC, UPC, and NSPC</li><li>Navigate code books and find applicable sections</li></ul><h3>1.1 History of Plumbing Codes</h3><p>Plumbing codes developed in response to public health crises in the late 19th century. Cholera and typhoid outbreaks traced to contaminated water supplies drove the creation of standardized plumbing practices.</p><h3>1.2 Major Model Plumbing Codes</h3><h4>International Plumbing Code (IPC)</h4><p>Published by ICC, adopted in approximately 35 states. Uses Water Supply Fixture Units (WSFU) and Drainage Fixture Units (DFU). Updated on 3-year cycle.</p><h4>Uniform Plumbing Code (UPC)</h4><p>Published by IAPMO, adopted primarily in western states. Uses Fixture Unit values that differ slightly from IPC. Strong adoption in California, Arizona, Nevada.</p><h4>National Standard Plumbing Code (NSPC)</h4><p>Published by PHCC, limited adoption primarily in New Jersey and some eastern states.</p><h3>1.3 Code Structure</h3><p>Typical chapters: (1) Administration, (2) Definitions, (3) General Regulations, (4) Fixtures, (5) Water Heaters, (6) Water Supply, (7) Sanitary Drainage, (8) Indirect Waste, (9) Vents, (10) Traps/Interceptors, (11) Storm Drainage, (12) Special Piping, (13) Referenced Standards.</p><h3>1.4 Referenced Standards</h3><ul><li>ASME A112 series: Plumbing fixture standards</li><li>ASSE 1000 series: Backflow prevention devices</li><li>ASTM: Pipe and fitting materials</li><li>AWWA: Water supply standards</li><li>NSF/ANSI 61: Drinking water components</li></ul>

<h3>Learning Objectives</h3><ul><li>Understand water pressure concepts and measurement</li><li>Calculate flow rates and velocities</li><li>Apply pressure loss calculations to plumbing systems</li></ul><h3>2.1 Pressure Fundamentals</h3><h4>Static Pressure</h4><p>P = 0.433 x h, where P = pressure (psi), h = height (feet). Example: 100 ft elevation = 43.3 psi.</p><h4>Code Requirements (IPC)</h4><ul><li>Minimum: 8 psi at highest fixture (IPC 604.5)</li><li>Maximum: 80 psi at any fixture (IPC 604.8)</li><li>PRV required when static exceeds 80 psi</li></ul><h3>2.2 Flow and Velocity</h3><p>Continuity: Q = A x V. Velocity: V = Q / (2.448 x d^2).</p><h4>Velocity Limits</h4><table border="1"><tr><th>Condition</th><th>Max Velocity</th></tr><tr><td>Cold water</td><td>8 fps</td></tr><tr><td>Hot water</td><td>5 fps</td></tr><tr><td>Noise-sensitive</td><td>4 fps</td></tr></table><h3>2.3 Friction Loss - Hazen-Williams</h3><p>hf = 10.44 x L x Q^1.85 / (C^1.85 x d^4.87)</p><h4>C Values</h4><table border="1"><tr><th>Material</th><th>C</th></tr><tr><td>Copper/PEX/CPVC</td><td>140-150</td></tr><tr><td>Galvanized (new)</td><td>120</td></tr><tr><td>Cast iron</td><td>130</td></tr></table><h3>2.4 Equivalent Length</h3><table border="1"><tr><th>Fitting</th><th>Eq. Length (diameters)</th></tr><tr><td>90-deg elbow</td><td>30</td></tr><tr><td>45-deg elbow</td><td>16</td></tr><tr><td>Tee (branch)</td><td>60</td></tr><tr><td>Gate valve</td><td>8</td></tr><tr><td>Globe valve</td><td>340</td></tr></table>

<h3>Learning Objectives</h3><ul><li>Apply Water Supply Fixture Units (WSFU) for pipe sizing</li><li>Apply Drainage Fixture Units (DFU) for waste sizing</li><li>Understand probability of simultaneous use</li></ul><h3>3.1 Fixture Unit System</h3><p>Developed by Dr. Roy B. Hunter at NBS in the 1920s-1940s. Based on probability - not all fixtures operate simultaneously. A fixture unit is a probability factor, not a flow rate.</p><h3>3.2 Water Supply Fixture Units (IPC 2021)</h3><table border="1"><tr><th>Fixture</th><th>Cold</th><th>Hot</th><th>Total</th></tr><tr><td>Bathtub</td><td>1.0</td><td>1.0</td><td>1.4</td></tr><tr><td>Lavatory</td><td>0.5</td><td>0.5</td><td>0.7</td></tr><tr><td>Shower</td><td>1.0</td><td>1.0</td><td>1.4</td></tr><tr><td>WC (tank)</td><td>2.2</td><td>-</td><td>2.2</td></tr><tr><td>WC (flush valve)</td><td>5.0</td><td>-</td><td>5.0</td></tr><tr><td>Urinal (FV)</td><td>3.0</td><td>-</td><td>3.0</td></tr><tr><td>Kitchen sink</td><td>1.0</td><td>1.0</td><td>1.4</td></tr></table><h3>3.3 Drainage Fixture Units (IPC 2021)</h3><table border="1"><tr><th>Fixture</th><th>DFU</th><th>Min Trap</th></tr><tr><td>Bathtub</td><td>2</td><td>1-1/2 in</td></tr><tr><td>Lavatory</td><td>1</td><td>1-1/4 in</td></tr><tr><td>Shower</td><td>2</td><td>2 in</td></tr><tr><td>WC (1.6 gpf)</td><td>3</td><td>3 in</td></tr><tr><td>Kitchen sink</td><td>2</td><td>1-1/2 in</td></tr><tr><td>Floor drain 2 in</td><td>2</td><td>2 in</td></tr></table><h3>3.4 WSFU to GPM Conversion</h3><table border="1"><tr><th>WSFU</th><th>GPM</th></tr><tr><td>5</td><td>8</td></tr><tr><td>10</td><td>12</td></tr><tr><td>50</td><td>29</td></tr><tr><td>100</td><td>43</td></tr><tr><td>500</td><td>115</td></tr></table>

<h3>Learning Objectives</h3><ul><li>Size water service and distribution piping</li><li>Apply the IPC sizing methodology</li><li>Select appropriate pipe materials</li></ul><h3>4.1 Pipe Materials</h3><table border="1"><tr><th>Material</th><th>Type</th><th>Application</th></tr><tr><td>Copper</td><td>K, L, M</td><td>All distribution</td></tr><tr><td>CPVC</td><td>SDR-11</td><td>Hot/cold</td></tr><tr><td>PEX</td><td>A, B, C</td><td>Residential</td></tr><tr><td>Ductile Iron</td><td>Class 150+</td><td>Underground</td></tr></table><p>Copper types: K=heaviest (underground), L=standard interior, M=lightest.</p><h3>4.2 IPC Sizing Procedure</h3><p><strong>Step 1:</strong> Available = Supply - Static - Meter - PRV - Min Fixture</p><p><strong>Step 2:</strong> Friction Rate = Available / Developed Length x 100</p><p><strong>Step 3:</strong> Size from tables at calculated friction rate</p><h3>4.3 Meter Sizing</h3><table border="1"><tr><th>Size</th><th>Max GPM</th><th>Loss (psi)</th></tr><tr><td>5/8 in</td><td>20</td><td>11</td></tr><tr><td>3/4 in</td><td>30</td><td>14</td></tr><tr><td>1 in</td><td>50</td><td>11</td></tr><tr><td>1-1/2 in</td><td>100</td><td>9</td></tr><tr><td>2 in</td><td>160</td><td>9</td></tr></table><h3>4.4 Minimum Sizes (IPC 610.3)</h3><table border="1"><tr><th>Fixture</th><th>Min</th></tr><tr><td>Lavatory</td><td>3/8 in</td></tr><tr><td>Shower</td><td>1/2 in</td></tr><tr><td>WC (tank)</td><td>3/8 in</td></tr><tr><td>WC (FV)</td><td>1 in</td></tr><tr><td>Urinal (FV)</td><td>3/4 in</td></tr></table>

<h3>Learning Objectives</h3><ul><li>Calculate hot water demand</li><li>Select and size water heaters</li><li>Design recirculation systems</li></ul><h3>5.1 Demand Calculation (ASHRAE)</h3><table border="1"><tr><th>Building</th><th>GPH</th></tr><tr><td>Residence</td><td>25-30/person</td></tr><tr><td>Apartment</td><td>20/unit</td></tr><tr><td>Office</td><td>1/person</td></tr><tr><td>Hotel</td><td>15-20/room</td></tr><tr><td>Restaurant</td><td>2-3/meal</td></tr><tr><td>Hospital</td><td>30-40/bed</td></tr></table><h3>5.2 Water Heater Sizing</h3><p>Recovery = Input BTU / (8.33 x Rise x Eff)</p><p>Tankless BTU = GPM x 8.33 x Rise x 60 / Eff</p><h3>5.3 Recirculation (IPC 607.2)</h3><p>Required when: developed length > 50 ft OR pipe volume > 0.5 gal</p><p>Pump sizing: Q = Heat Loss / (500 x Delta-T)</p><h4>System Types</h4><ul><li>Continuous: 24/7 operation</li><li>Timer: Scheduled operation</li><li>Demand: User-activated</li><li>Temperature: Aquastat-controlled</li></ul><h3>5.4 Temperature Requirements</h3><table border="1"><tr><th>Use</th><th>Temp</th></tr><tr><td>Public lavatory</td><td>110F max</td></tr><tr><td>Shower/bath</td><td>120F max</td></tr><tr><td>Commercial kitchen</td><td>180F</td></tr><tr><td>Legionella storage</td><td>140F min</td></tr></table><p>ASSE 1016/1070: TMV required when storage > safe delivery temp.</p>

<h3>Learning Objectives</h3><ul><li>Understand backflow causes</li><li>Identify cross-connections</li><li>Select backflow devices</li></ul><h3>6.1 Backflow Types</h3><ul><li><strong>Backpressure:</strong> Downstream pressure exceeds supply</li><li><strong>Backsiphonage:</strong> Negative pressure creates suction</li></ul><h3>6.2 Hazard Levels</h3><table border="1"><tr><th>Level</th><th>Description</th></tr><tr><td>Low (Pollutant)</td><td>Non-toxic, affects aesthetics</td></tr><tr><td>High (Contaminant)</td><td>Could cause illness/death</td></tr></table><h3>6.3 Prevention Devices</h3><h4>Air Gap (AG)</h4><p>Physical separation 2x diameter, min 1 in. Highest protection.</p><h4>RPZ (ASSE 1013)</h4><p>Two checks + relief valve. High hazard. Install 12 in above floor. Annual testing.</p><h4>DCVA (ASSE 1015)</h4><p>Two checks in series. Low hazard only. Fire sprinkler, irrigation.</p><h4>PVB (ASSE 1020)</h4><p>Backsiphonage only. 12 in above highest outlet. Irrigation.</p><h3>6.4 Selection Guide</h3><table border="1"><tr><th>Application</th><th>Device</th></tr><tr><td>Boiler makeup</td><td>RPZ/Air Gap</td></tr><tr><td>Fire sprinkler</td><td>DCVA</td></tr><tr><td>Sprinkler w/antifreeze</td><td>RPZ</td></tr><tr><td>Irrigation (chem)</td><td>RPZ</td></tr><tr><td>Cooling tower</td><td>RPZ/Air Gap</td></tr><tr><td>Laboratory</td><td>Air Gap/RPZ</td></tr></table>

<h3>Learning Objectives</h3><ul><li>Understand gravity drainage</li><li>Identify DWV components</li><li>Apply slope requirements</li></ul><h3>7.1 Gravity Principles</h3><ul><li>Continuous downward slope to sewer</li><li>Adequate diameter for capacity</li><li>Proper venting for pressure</li><li>Trap seals prevent gas entry</li></ul><h3>7.2 Components</h3><ul><li><strong>Building Drain:</strong> Lowest horizontal collector</li><li><strong>Building Sewer:</strong> To public sewer</li><li><strong>Soil Pipe:</strong> Carries fecal matter</li><li><strong>Waste Pipe:</strong> Non-fecal discharge</li><li><strong>Stack:</strong> Vertical soil/waste/vent pipe</li></ul><h3>7.3 Slope Requirements (IPC)</h3><table border="1"><tr><th>Size</th><th>Min Slope</th></tr><tr><td>2-1/2 in or less</td><td>1/4 in/ft</td></tr><tr><td>3-6 in</td><td>1/8 in/ft</td></tr><tr><td>8 in+</td><td>1/16 in/ft</td></tr></table><h3>7.4 Materials</h3><table border="1"><tr><th>Material</th><th>Use</th></tr><tr><td>Cast Iron</td><td>Commercial, high-rise</td></tr><tr><td>PVC DWV</td><td>Residential</td></tr><tr><td>ABS</td><td>Where permitted</td></tr><tr><td>Copper DWV</td><td>Exposed</td></tr></table><h3>7.5 Traps (IPC 708)</h3><p>Seal: 2-4 in depth. P-trap standard. S-trap prohibited.</p><h4>Trap Arm Length</h4><table border="1"><tr><th>Trap</th><th>Max</th></tr><tr><td>1-1/4 in</td><td>2.5 ft</td></tr><tr><td>1-1/2 in</td><td>3.5 ft</td></tr><tr><td>2 in</td><td>5 ft</td></tr><tr><td>3 in</td><td>6 ft</td></tr></table><h3>7.6 Cleanouts</h3><ul><li>Base of each stack</li><li>Direction changes > 45 deg</li><li>Every 100 ft in building drain</li><li>At building drain/sewer connection</li></ul>

<h3>Learning Objectives</h3><ul><li>Size building drains using DFU</li><li>Size horizontal branches</li><li>Size stacks for multi-story</li></ul><h3>8.1 Horizontal Branches (IPC 710.1)</h3><table border="1"><tr><th>Size</th><th>Max DFU (1/4 in)</th><th>Max DFU (1/8 in)</th></tr><tr><td>1-1/2 in</td><td>3</td><td>-</td></tr><tr><td>2 in</td><td>6</td><td>-</td></tr><tr><td>3 in</td><td>20*</td><td>36</td></tr><tr><td>4 in</td><td>160</td><td>180</td></tr><tr><td>6 in</td><td>620</td><td>700</td></tr></table><p>*Max 2 WC on 3 in branch</p><h3>8.2 Stacks and Building Drains</h3><table border="1"><tr><th>Size</th><th>DFU/Story</th><th>Total Stack</th><th>Bldg Drain</th></tr><tr><td>2 in</td><td>6</td><td>10</td><td>21</td></tr><tr><td>3 in</td><td>20*</td><td>48*</td><td>42**</td></tr><tr><td>4 in</td><td>90</td><td>240</td><td>216</td></tr><tr><td>6 in</td><td>350</td><td>960</td><td>840</td></tr></table><p>*Max 2 WC/story, **Max 6 WC total</p><h3>8.3 Stack Offsets</h3><p>Horizontal offset: size as building drain. May need relief venting.</p><h3>8.4 Example: 5-Story Office</h3><p>Per floor: 4 WC + 2 UR + 6 Lav + sinks = 28 DFU. Total: 140 DFU.</p><p>Stack: 4 in (240 max). Building drain: 4 in at 1/8 in slope (180 max).</p>

<h3>Learning Objectives</h3><ul><li>Understand venting purpose</li><li>Apply vent types</li><li>Size vents per IPC</li></ul><h3>9.1 Purpose of Venting</h3><ol><li>Maintain trap seals</li><li>Allow air circulation for flow</li><li>Dissipate sewer gases</li></ol><h4>Trap Seal Loss</h4><ul><li>Self-siphonage: Own discharge creates suction</li><li>Induced siphonage: Shared drain negative pressure</li><li>Backpressure: Positive pressure pushes out</li><li>Evaporation: Non-use</li></ul><h3>9.2 Vent Types</h3><ul><li><strong>Individual:</strong> One vent per trap</li><li><strong>Common:</strong> Two back-to-back fixtures</li><li><strong>Wet Vent:</strong> Drain + vent (IPC 912)</li><li><strong>Circuit:</strong> Branch for floor outlets</li><li><strong>Stack Vent:</strong> Extension of stack</li><li><strong>AAV:</strong> One-way valve (ASSE 1051)</li></ul><h3>9.3 Individual Vent Sizing</h3><table border="1"><tr><th>Drain</th><th>Min Vent</th></tr><tr><td>1-1/4 in</td><td>1-1/4 in</td></tr><tr><td>1-1/2 in</td><td>1-1/4 in</td></tr><tr><td>2 in</td><td>1-1/2 in</td></tr><tr><td>3 in</td><td>2 in</td></tr><tr><td>4 in</td><td>2 in</td></tr></table><h3>9.4 Vent Stack Sizing</h3><table border="1"><tr><th>Stack</th><th>DFU</th><th>Vent</th><th>Max Length</th></tr><tr><td>2 in</td><td>12</td><td>1-1/2 in</td><td>75 ft</td></tr><tr><td>3 in</td><td>42</td><td>2 in</td><td>90 ft</td></tr><tr><td>4 in</td><td>216</td><td>3 in</td><td>100 ft</td></tr></table><h3>9.5 Installation</h3><ul><li>Slope upward 1/4 in/ft min</li><li>Connect above drain centerline</li><li>Terminate 6 in above roof</li><li>10 ft from windows/intakes</li></ul>

<h3>Learning Objectives</h3><ul><li>Calculate roof drainage</li><li>Size drains, leaders, mains</li><li>Understand secondary drainage</li></ul><h3>10.1 Rainfall Rates (100-yr, 1-hr)</h3><table border="1"><tr><th>Location</th><th>in/hr</th></tr><tr><td>Seattle</td><td>1.0</td></tr><tr><td>Denver</td><td>2.5</td></tr><tr><td>Chicago</td><td>3.0</td></tr><tr><td>New York</td><td>3.5</td></tr><tr><td>Houston</td><td>4.5</td></tr><tr><td>Miami</td><td>5.0</td></tr></table><h3>10.2 Flow Rate</h3><p>Q = (A x R) / 96.23, where Q=gpm, A=SF, R=in/hr</p><h3>10.3 Drain/Leader Sizing (at 1 in/hr)</h3><table border="1"><tr><th>Size</th><th>Max SF</th><th>GPM</th></tr><tr><td>2 in</td><td>720</td><td>23</td></tr><tr><td>3 in</td><td>1,610</td><td>67</td></tr><tr><td>4 in</td><td>3,460</td><td>144</td></tr><tr><td>6 in</td><td>10,200</td><td>424</td></tr><tr><td>8 in</td><td>22,000</td><td>913</td></tr></table><p>Adjust: Capacity = Table / Rainfall Rate</p><h3>10.4 Secondary Drainage (IPC 1107)</h3><ul><li>Required when parapet allows ponding</li><li>Handle 100% of primary capacity</li><li>Discharge visibly</li><li>Set 2 in above primary inlet</li></ul><h3>10.5 Example: 40,000 SF Warehouse, Chicago</h3><p>Flow = 40,000 x 3 / 96.23 = 1,247 gpm</p><p>6 in drains: 10,200/3 = 3,400 SF each. Need 12 drains.</p><p>Main: 10 in handles 41,400/3 = 13,800 SF.</p>

<h3>Learning Objectives</h3><ul><li>Understand gas piping materials</li><li>Calculate gas demand</li><li>Size using longest length method</li></ul><h3>11.1 Gas Properties</h3><h4>Natural Gas</h4><ul><li>Heating: 1,000 BTU/CF</li><li>SG: 0.60 (lighter than air)</li><li>Supply: 7 in WC residential, 2 psi commercial</li></ul><h4>Propane</h4><ul><li>Heating: 2,500 BTU/CF</li><li>SG: 1.52 (heavier than air)</li></ul><h3>11.2 Materials (IFGC 403)</h3><table border="1"><tr><th>Material</th><th>Use</th></tr><tr><td>Black Steel</td><td>Above/below grade</td></tr><tr><td>CSST</td><td>Above grade, bonded</td></tr><tr><td>PE</td><td>Below grade only</td></tr></table><h3>11.3 Demand Calculation</h3><p>CFH = BTU/hr / 1,000 (nat gas) or /2,500 (propane)</p><h4>Appliance Inputs</h4><table border="1"><tr><th>Appliance</th><th>BTU/hr</th></tr><tr><td>Furnace</td><td>60-120K</td></tr><tr><td>Water heater</td><td>36-40K</td></tr><tr><td>Range (res)</td><td>65K</td></tr><tr><td>Range (comm)</td><td>180K</td></tr><tr><td>RTU heating</td><td>100-400K</td></tr></table><h3>11.4 Longest Length Method</h3><ol><li>Total demand for building</li><li>Longest run meter to farthest appliance</li><li>Use this length for ALL sections</li><li>Size each section for its demand</li></ol><h4>Steel Pipe Capacity (CFH)</h4><table border="1"><tr><th>Size</th><th>50 ft</th><th>100 ft</th><th>200 ft</th></tr><tr><td>1/2 in</td><td>88</td><td>62</td><td>43</td></tr><tr><td>3/4 in</td><td>175</td><td>123</td><td>86</td></tr><tr><td>1 in</td><td>345</td><td>243</td><td>170</td></tr><tr><td>1-1/2 in</td><td>1,100</td><td>773</td><td>541</td></tr><tr><td>2 in</td><td>2,100</td><td>1,480</td><td>1,040</td></tr></table><h3>11.5 Installation</h3><ul><li>Drip legs: 3 in min, before appliances</li><li>Shutoffs: meter, building entrance, each appliance</li></ul>

<h3>Learning Objectives</h3><ul><li>Understand medical gas systems</li><li>Apply NFPA 99 requirements</li><li>Select fixtures per code</li><li>Calculate fixture counts</li></ul><h3>12.1 Medical Gases (NFPA 99)</h3><table border="1"><tr><th>System</th><th>Pressure</th></tr><tr><td>Oxygen</td><td>50-55 psig</td></tr><tr><td>Medical Air</td><td>50-55 psig</td></tr><tr><td>Nitrous Oxide</td><td>50-55 psig</td></tr><tr><td>Nitrogen</td><td>160-180 psig</td></tr><tr><td>Vacuum</td><td>15-19 in Hg</td></tr></table><h4>Categories</h4><ul><li>Cat 1: Life support (OR, ICU)</li><li>Cat 2: Injury potential</li><li>Cat 3: Discomfort only</li></ul><h3>12.2 Water Conservation</h3><table border="1"><tr><th>Fixture</th><th>Max</th><th>WaterSense</th></tr><tr><td>WC</td><td>1.6 gpf</td><td>1.28 gpf</td></tr><tr><td>Urinal</td><td>1.0 gpf</td><td>0.5 gpf</td></tr><tr><td>Lav (public)</td><td>0.5 gpm</td><td>0.5 gpm</td></tr><tr><td>Showerhead</td><td>2.5 gpm</td><td>2.0 gpm</td></tr></table><h3>12.3 ADA Requirements</h3><ul><li>Lavatory: 34 in max rim, knee clearance</li><li>WC: 17-19 in seat, grab bars</li><li>Urinal: 17 in max rim</li><li>Drinking fountain: high-low combo</li></ul><h3>12.4 Fixture Counts (IPC 403.1)</h3><h4>Assembly</h4><p>WC: M 1/125, F 1/65. Lav: 1/200. DF: 1/500.</p><h4>Business</h4><p>WC: 1/25 (1-50), 1/50 (over). Lav: 1/40. DF: 1/100.</p><h4>Educational</h4><p>WC: 1/50. Lav: 1/50. DF: 1/100.</p><h3>12.5 Key Principles</h3><ol><li>Code compliance first - verify local amendments</li><li>Pressure management determines design</li><li>Fixture units prevent oversizing</li><li>Proper slope and venting essential</li><li>Backflow prevention protects health</li></ol><h4>Common Errors</h4><ul><li>Undersizing using straight-line distance</li><li>Ignoring fitting pressure losses</li><li>Improper vent sizing</li><li>Missing backflow protection</li><li>Inadequate storm drainage</li></ul>