National Plumbing Code Chapter 14 — Quality & Weights of Materials
NPC 2000
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Chapter 14 · Quality & Weights of Materials · Referenced Standards
⚖️ Quality & Weights of Materials

Quality & Weights of Plumbing Materials

Chapter 14 sets the material-quality baseline for the whole code: every pipe, fitting, trap, fixture, and device must be defect-free, factory-marked, and meet listed weights and dimensions. It defines IPS sizing, lead weights/thicknesses, copper tubing types and their color-stripe identification (K/L/M/DWV), and the dimensional tables for ferrules, bushings, closet rings, cleanouts, and drainage valves.

🏷️ Factory Marking Required 🟢 Copper Stripe Codes 📋 Ferrule & Bushing Tables 🚽 4 Bolts per Water Closet
§ 1401

Material Quality & Marking

Defect-free, listed, and factory-marked — no field markings

§ 1402

IPS Sizing & Lead Weights

Standard pipe dimensions and minimum lead weights/thicknesses

Iron Pipe Size (IPS): all iron, steel, brass, and copper pipe shall conform to standard IPS dimensions and the appropriate structural weights.
Lead ApplicationMinimum WeightMinimum Thickness
Safe pans19.56 kg/m²1.6 mm
Flashings / vent terminals14.63 kg/m²1.2 mm
Lead bends & traps3.2 mm (wall)
§ 1403

Copper Tubing & Stripe Codes

Type requirements by use and the color-stripe identification system

🎨
Identification — §1403
Hard-drawn copper carries a continuous, indelible color stripe ≥6.4 mm wide
Copper TypeStripe ColorTypical Use
Type K GreenHeaviest wall — underground / high pressure
Type L BlueWater supply (minimum for supply piping)
Type M RedAbove-ground water (per exception)
Type DWV YellowDrain, waste & vent
§ 1404

Caulking Ferrules & Soldering Bushings

Tables 14-1 and 14-2 — required dimensions and minimum weights

Table 14-1 — Caulking Ferrules (red cast brass, bronze, or copper)

Pipe SizeInside DiameterLengthMin Weight Each
51 mm (2″)57.2 mm114.3 mm0.454 kg
76 mm (3″)82.6 mm114.3 mm0.790 kg
102 mm (4″)108.0 mm114.3 mm1.132 kg

Table 14-2 — Soldering Bushings (bronze, copper, or heavy cast red brass)

Pipe SizeMin Weight EachPipe SizeMin Weight Each
32 mm (1¼″)0.168 kg63 mm (2½″)0.622 kg
38 mm (1½″)0.224 kg76 mm (3″)0.908 kg
51 mm (2″)0.392 kg102 mm (4″)1.586 kg
§ 1405

Closet Rings & Anchorage

Water-closet flange dimensions and the 4-bolt rule

RequirementSpecification
Closet ring (flange) diameter≈ 178 mm
Flange & groove face (with soil pipe)38 mm wide — to seat the wax ball / gasket
Caulked-on flange thickness≥ 6.4 mm thick · 51 mm overall depth
WC base anchorageDouble pair of bolts = exactly 4 bolts per water closet, corrosion-resistant brass or copper, into the concrete floor
§ 1406

Cleanouts, Drainage Fittings & Valves

Material and configuration requirements

Valve Line SizeRequired Body Material
≤ 51 mm (2″)All brass or bronze
< 102 mm (under 4″)Cast brass or bronze body
≥ 102 mm (4″+)Cast-iron body
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