Plumbing System Training

The water supply side of plumbing involves all the components and materials that bring potable (drinkable) water into a building and distribute it to various fixtures. A basic understanding of these elements is essential for construction professionals facilitate effective communication with plumbing contractors.

I. Piping Materials

Identifying the types of pipes used is essential, as they dictate the joining methods, applications, and limitations.

• Copper:

  • Appearance: Typically a reddish-brown color, but can turn green (patina) over time.

  • Types:

    • Type K: Thickest wall, used for underground and heavy-duty applications.

    • Type L: Medium wall, commonly used for interior water supply.

    • Type M: Thinnest wall, used for low-pressure applications.

  • Joining Method: Soldering (heating and applying solder) or compression fittings.

  • Applications: Hot and cold water distribution.

PEX (Cross-Linked Polyethylene):

• Appearance: Flexible plastic tubing, often colored (red for hot, blue for cold, white for general).

• Types: PEX-A, PEX-B, PEX-C (differ in manufacturing process, affecting flexibility and joining).

• Joining Method: Crimp rings, expansion fittings, or push-fit connectors.

• Applications: Hot and cold water distribution, especially in "home-run" systems.

CPVC (Chlorinated Polyvinyl Chloride):

• Appearance: Rigid plastic pipe, typically cream or light yellow.

• Joining Method: Solvent cementing (using primer and cement).

• Applications: Hot and cold water distribution.

• Note: This is an extremely brittle material that becomes more brittle with time. Exercise extreme caution when working around this material as it cracks & splits easily.

Galvanized Steel:

• Appearance: Silver-gray, rigid steel pipe.

• Joining Method: Threaded connections.

• Applications: Older water supply systems (less common in new construction due to corrosion issues).

• Note: Galvanized coating is installed prior to threads being cut, the installer cutting the threads would remove the galvanized coating revealing regular steel that's prone to rust. This material rusts & breaks down on the interior side.  This material when left without water in it will develop pinhole leaks leading to water damage when the water is turned back on. Such as situations such as long periods during fire reconstruction projects.

Polyethylene (PE):

• Appearance: Black, flexible pipe.

• Joining Method: Mechanical fittings, heat fusion.

• Applications: Primarily for underground cold water service lines (from the meter to the building), or well supply.

II. Valves

Valves control the flow of water. Knowing their types and functions is vital for system operation and maintenance.

• Main Shut-Off Valve:

  • Appearance: Usually a large valve located where the water service enters the building.

  • Function: To turn off the entire water supply to the building.

  • Types:

    • Ball Valve: Quarter-turn handle.

    • Gate Valve: Multi-turn wheel handle. (well known for the stem to break on older units. Stem can break either with the valve open, or closed)

Individual Shut-Off Valves:

• Appearance: Smaller valves located near fixtures (sinks, toilets).

• Function: To isolate water supply to individual fixtures for repairs.

• Types:

  • Angle Stop Valve.

  • Straight Stop Valve.

Check Valve:

• Function: A valve with an arrow indicating the direction of flow. 

Vacuum Breaker:

• Function: prevents water flow from returning back into the main water lines due to a drop in pressure inside.

Backflow Preventer: 

• Function: To prevent backflow (water flowing in the wrong direction).

Does the same as the check valve, but will work with a loss of pressure at the street side, to prevent water from draining back into the main water lines.

Pressure Reducing Valve (PRV):

• Appearance: Bell-shaped device, often with an adjustment screw.

• Function: To regulate incoming water pressure to a safe level.

III. Fittings

Fittings connect pipes and change their direction.

• Couplings:

  • Function: Join two straight lengths of pipe.

  • Types:

    • Standard Coupling

    • Reducing Coupling (connects pipes of different sizes).

Elbows:

• Function: Change the direction of a pipe.

• Angles: 90-degree, 45-degree, etc.

Tees:

• Function: Create a branch line from a main line.

Adapters:

• Function: Connect different types of pipes

  • Connects different materials (e.g., copper to PEX).

  • Connects different attachment types (eg., male or female connections)

IV. Other Essential Components

• Water Meter:

  • Appearance: A device that measures water consumption, usually located where the water service enters the property.

  • Function: To track water usage for billing.

• Backflow Preventer:

  • Function: Prevents contaminated water from flowing back into the potable water supply. Several types (see Valves section).

• Expansion Tank:

  • Appearance: A tank connected to the hot water line.

  • Function: Absorbs the expansion of water as it's heated, preventing pressure buildup.

The drain, waste, and vent (DWV) system is a critical part of any building's plumbing, responsible for safely removing wastewater and sewage while also providing proper ventilation to prevent sewer gases from entering the building. A good understanding of DWV system components and materials is essential for construction professionals.

I. Piping Materials

• PVC (Polyvinyl Chloride):

  • Appearance: Rigid white or gray plastic pipe.

  • Joining Method: Solvent cementing (primer and cement).

  • Applications: Drain, waste, and vent lines.

• ABS (Acrylonitrile Butadiene Styrene):

  • Appearance: Rigid black plastic pipe.

  • Joining Method: Solvent cementing (primer and cement).

  • Applications: Drain, waste, and vent lines (check local codes, as PVC is more common in some areas).

Cast Iron:

• Appearance: Dark gray, heavy, and rigid pipe.

• Joining Method:

  • Hub and Spigot: Molten lead and oakum.

  • No-Hub: Mechanical couplings (band clamps).

• Applications: Drain and waste lines, especially for larger buildings, underground, and where noise reduction is needed.

Copper:

• Appearance: Reddish-brown, rigid pipe.

• Joining Method: Soldering.

• Applications: Can be used for drain lines in some situations, but less common due to cost.

Clay: 

• Appearance: Earthen material, often orange or brown. 

• Joining Method: Bell and spigot. 

•  Applications: Historically used for underground sewer lines. 

II. DWV System Components

• Traps:

  • Appearance: U-shaped or P-shaped section of pipe.

  • Function: Holds a small amount of water to prevent sewer gases from entering the building.

  • Types:

    • P-trap: Common under sinks and lavatories.

    • S-trap: Currently prohibited for use, due to the syphoning caused that clears the water from the trap.

    • Drum-trap: Currently still legal for use, but most plumbers will not install or replace due to their clogging, and difficulty clearing.

DWV systems use various fittings to connect pipes and change direction.

• Elbows:

  • Function: Change pipe direction (90-degree, 45-degree, etc.).

  • Types: Long sweep, short sweep

• Tees:

  • Function: Create a branch line.

  • Types:

    • Sanitary Tee: For vertical to horizontal drainage.

    • Wye: Used for drain connections

• Couplings:

  • Function: Join two pipes.

    • Typically solvent glued with PVC or ABS

    • They're available in:

      • Reducer Couplings: Changes from a smaller pipe to a larger pipe

      • Straight Coupling: From 2 pipes of the same size.

      • Bushing Coupling: Allows connection of a smaller pipe to a larger fitting by slipping into the fitting.

• Adapters: 

  • Function: Connect different pipe materials

    • mechanical connection with bands

    • forced interference fit with rubber gaskets.

• Cleanouts:

  • Appearance: A fitting with a removable plug.

  • Function: Provides access to the drain line for cleaning out clogs.

  • Location: Typically found at changes in direction, where vertical and horizontal pipes meet, and at the end of runs.

Clean Out Caps: 

• May be found in various locations:

  • buried outdoors, just below the surface of the grass.

  • Parking lots in asphalt.

  • Indoors with a decorative cap.

• Vents:

  • Function: Allow air into the DWV system to:

    • Prevent vacuum that would slow drainage.

    • Allow sewer gases to vent outside the building.

  • Types:

    • Main Vent (Stack Vent): Vertical pipe extending through the roof.

    • Branch Vent: Connects to a drain line and then to the main vent.

    • Individual Vent: Connects to a single trap.

    • Air Admittance Valve (AAV):

      • Appearance: A one-way valve that allows air into the drain system.

      • Function: Alternative to traditional venting, allows air in, prevents sewer gas escape.

• Soil Stack:

  • Appearance: A vertical pipe that carries both waste and water from fixtures and connects to the building drain.

  • Function: The main vertical drain pipe in a building.

• Waste Stack:

  • Appearance: A vertical pipe that carries wastewater, not toilet water.

  • Function: Carries wastewater from fixtures to the building drain.

• Building Drain:

  • Appearance: The lowest horizontal piping of the drainage system that receives discharge from waste and soil stacks and conveys it to the building sewer.

  • Function: Carries wastewater from the building to the building sewer.

• Building Sewer:

  • Appearance: The pipe from the end of the building drain to the public sewer or septic tank.

  • Function: Carries wastewater from the building drain to the point of disposal.

The Problem with Polybutylene Piping:

• Polybutylene (PB) pipes were widely used in residential construction from the late 1970s to the mid-1990s.  

• These pipes, including those sold under the brand name "Qest," were initially popular due to their low cost and ease of installation.

• However, it was discovered that PB pipes are prone to premature failure, often due to reactions with chlorine and other chemicals found in municipal water supplies.  

• These failures can lead to significant water damage, mold growth, and costly repairs.  

Class-Action Lawsuits:

• Due to the widespread failures of PB piping, numerous class-action lawsuits were filed against manufacturers.

• One of the most significant cases was Cox v. Shell Oil Company (1995).

  • This lawsuit resulted in a substantial settlement, establishing a fund to help homeowners replace their defective PB piping systems.  

• Another lawsuit was Spencer v. DuPont (1995). This addressed defective fittings used with the PB pipes.

• It is important to understand that the time frame to file claims for those lawsuits has long since passed.

Key Takeaways:

• Although the production and installation of PB pipes ceased in the mid-1990s, many homes still contain this material.

• Homeowners with PB piping are strongly advised to replace it to avoid potential water damage.  

• The presence of PB piping can also affect property values and insurance coverage.  

What Homeowners Should Do:

• If you suspect your home has PB piping, consult a licensed plumber to assess the situation.

• Replacing PB piping with modern materials like PEX or CPVC is the safest long-term solution.

What Homeowners Should Do After Water Damage involving PB pipe:

• Potential for Subrogation in PB Cases:

  • While the major class-action lawsuits have concluded, there might be limited situations where subrogation is possible.

  • The insurance company will review the specifics of the case, the age of the pipes, and any relevant documentation to determine if pursuing subrogation is viable.

  • However, because of the age of the product, and the previous class action lawsuits, it is unlikely that a insurance company would be able to successfully subrogate against the long gone manufacturers.

• Insurance Company's Decision: The decision to subrogate rests with the insurance company. They will weigh the costs and benefits of pursuing legal action.