Plastic Pipe Fittings Overview

Plastic Pipe Fittings

• Available in all sizes and plastic types
• Same names as those for steel pipe
• Do not mix pipe and fittings of different types of plastic

Repairing Plastic Pipe

• Usually repaired by cutting out the defective section and replacing it
• Use matching type of plastic and solvent cement

Adapters

• Connect different types of pipe or tubing
• Examples include elbows, tees, and couplings in various combinations of male or female fittings

Push-on Pipe Fittings

• Designed to be installed without any special tool
• Quick, leak-proof connection
• Used in potable water, hydronic hot water heating systems, and condensate drain lines
• Can be removed and reused

Crimp-on Pipe Fittings

• Use special installation tool to crimp the fitting around the pipe
• Used in potable water, hydronic hot water heating systems, and condensate drain lines
• If fitting needs to be removed it will often have to be cut out
• May not be reused

Pipe Thread

• Tapering causes the threads to bind and seal during tightening
• Pipe compound (dope) or Teflon tape is used to ensure a leakproof seal
• Check with local building authorities for requirements.

Tools Used with Steel Pipe

• Cutting and threading steel pipe requires specialized tools such as:
  • Pipe vise
  • Pipe cutter
  • Pipe reamer
  • Pipe wrench
  • Pipe die

### Pipe Vise

• Used to securely hold steel pipe in position for cutting and threading
• Two basic types - chain and yoke
• Some are equipped with an electric motor to rotate the pipe

### Pipe Cutter

• Clamps around the pipe
• Wheel blade cuts around the pipe
• Heavy-duty use for cutting steel pipe
• Different sizes for different diameter pipe

Pipe Reamer

• Used to remove the inside burr from cut ends
• Secure pipe in a vise
• Match reamer size to pipe size
• Can be done on black and galvanized pipe

### Pipe Wrench

• Designed for holding and turning steel pipe and fittings
• Jaw and chain types leave marks
• Strap-type leaves no marks
• Pipe wrenches are often used in pairs

Pipe Die

• Used to cut threads on the outside of steel pipe
• Each die is accurately sized to fit a particular size of steel pipe

### Fittings for Steel Pipe

• Components used to join sections of pipe
• Made of annealed cast iron, called malleable fittings
• Fittings are threaded
• Sized according to the nominal size (ID) of the pipe being used

### Types ofPipe Fittings

• Elbows:

  • Change the direction of a pipe run
  • Available in all sizes
  • 90° or 45° angles

• Couplings:

  • Connect two lengths of pipe in a straight line
  • Short fitting with female threads at each end
  • Reducers are available

• Tees:

  • Used to create a branch from an existing line
  • Available in almost any combination of sizes

• Reducing bushings:

  • Male threads on outside, female threads on inside
  • Used to reduce the size of female opening

• Caps and plugs:

  • Used to seal openings
  • Caps have female threads
  • Plugs have male threads

• Unions:

  • Type of coupling
  • Must be used to complete final pipe run

### Nipples

• Short lengths of pipe threaded on each end
• Used to connect fittings that are close together

Repairing Steel Pipe

• Leaks are usually caused by loose connections or corrosion of the pipe
• Loose connections can be tightened
• Rusting or damaged sections must be replaced

Rigid Plastic Pipe

• Usage has increased in recent years
• An acceptable and inexpensive means of transferring many types of liquids
• Often replaces steel pipe in numerous applications
• Check local building codes and authorities for usage and application

Advantages of Rigid Plastic Pipe

• Resistant to corrosive liquids
• Does not rot
• Resists growth of bacteria, algae, and fungi
• Provides maximum flow rates
• Tough and strong
• Easier to handle, join, and install than metal
• Less expensive than metal

Types of Plastic Pipe

• ABS (black pipe)

  • Used only for drain, waste, and vent piping

• PVC (white pipe)

  • Used for cold water supply, drain lines, and some venting

• CPVC (off-white, cream, tan, or grey pipe)

  • Used for hot and cold water lines or drains

### Plastic Pipe Sizes

• Pipes and fittings are manufactured to conform to nominal pipe sizing of steel pipe
• Inside (flow) diameter changes slightly with the schedule number
• Schedule 80 has a thicker wall
• Available in 20-foot lengths

### Solvent-Welding

• A process where plastic pipe is joined chemically, also called cementing
• Follow instructions carefully and resist shortcuts to avoid joint failures
• Different solvent cement is required for each type of plastic pipe

Using Solvent Cement

• Purchased in one-pint metal containers with an application dauber
• Different solvent cement is required for each plastic type (ABS, CPVC, PVC)
• Always cover when not in use, do not use thinner
• Special care is needed when joining two different types of plastic pipe

### Solvent Cement Safety

• Solvent cements and primers are extremely flammable and emit dangerous vapors
• Avoid contact with eyes, skin, and clothing
• Close container after each use
• If comes in contact with skin or eyes, flush with water for at least 15 minutes and seek medical attention

### Pipe Preparation

• Proper preparation is important for a satisfactory joint
  • Pipe must be cut square
  • Burrs removed
  • Ends beveled to ensure joint will be properly solvent-welded and leakproof

Primer Skin Contact

• Apply primer using a tool, like a dauber or brush
• Do not use a rag

Making Plastic Pipe Joints

• Applying cement:

  • Apply a generous coating around the outside surface of the pipe
  • Then apply an even layer around the inside of the socket (not too much)

• Joining pipe and fitting:

  • Insert the pipe to the full socket depth
  • Rotate one-quarter turn
  • Hold together firmly for 20 to 30 seconds