2 Inch Pipe Calculator & Complete Guide
Calculate flow rates, capacity, and sizing for 2 inch pipes. Complete guide to 2" pipe specifications for water supply and drainage applications with flow capacity data.
2 inch pipe serves dual purposes in plumbing systems: as a larger water supply line for commercial applications and as a standard size for drainage and waste systems. Understanding 2" pipe flow capacity and drainage applications is essential for both water supply and DWV system design.
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Calculate the appropriate pipe diameter for your plumbing system based on flow requirements.
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Flow Capacity by Material
Copper (Type L)
1.985" ID, commercial supply
PEX
1.935" ID, flexible installation
PVC (Drainage)
2.067" ID, DWV applications
2" Pipe Flow Capacity by Material
Maximum recommended flow rates (GPM) for 2" pipe. Note: For drainage applications, flow is gravity-driven and typically lower than pressure systems.
| Material | Inside Diameter | C-Value | Max Flow @ 6 ft/s (GPM) | Primary Use |
|---|---|---|---|---|
| Copper (Type L) | 1.985" | 140 | 55.4 | Commercial water supply |
| PEX | 1.935" | 150 | 54.1 | Large flexible supply |
| PVC (Drainage) | 2.067" | 150 | 60.4 | Shower/tub drains, DWV |
Common Uses
2" pipe is commonly used in the following applications:
- Commercial water supply
- Shower and tub drains
- Branch drainage lines
- Large fixture connections
- Main drainage branches
Applications
- Commercial water supply
- Shower drain lines
- Bathtub drain lines
- Large fixture drainage
- Branch DWV lines
- Main drainage branches
- Sump pump discharge
- Irrigation main lines
Frequently Asked Questions
What is the flow rate for 2 inch pipe?
For water supply: Copper = 55.4 GPM, PEX = 54.1 GPM at 6 ft/s velocity. For drainage (PVC): 60.4 GPM capacity, though actual flow is gravity-driven and typically 2-5 GPM for residential applications.
Is 2 inch pipe required for shower drains?
Yes, most codes require minimum 2" pipe for shower and bathtub drains. This ensures adequate flow capacity and prevents clogs. Use our Drainage Slope Calculator to determine proper slope for 2" drain lines.
Can 2 inch pipe be used for water supply?
Yes, 2" pipe is commonly used for commercial water supply applications where high flow capacity is needed. For residential applications, 2" is typically overkill unless serving very large homes or multiple units.
What's the minimum slope for 2 inch drain pipe?
Minimum slope for 2" drain pipe is 1/4" per foot (2% grade) per IPC/UPC codes. This provides self-cleaning velocity. Use our Drainage Slope Calculator to determine exact slope requirements for your installation.
Code Compliance
2" pipe is approved for both water supply and drainage per IPC and UPC codes. Minimum size for shower/tub drains is 2" per most codes. Always verify local code requirements for your specific application.
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