Sewer - Force Main

Introduction

After more than 30 years of use in M&I sewer applications, polyethylene (PE) pipe is a proven solution. Independent testing of PE in sewer service for 25 years showed no significant changes in the material’s physical or chemical properties. The inherent properties of HDPE accommodate all the desired performance characteristics needed for these demanding applications:
  • Forced Sewer Mains
  • Pipeline Rehabilitation or Trenchless Pipeline Replacement
  • Combined Storm and Sanitary Sewer Lines
  • Sludge Lines
  • Intake and Outfall Lines
  • Culvert Relining
  • Digester Lines
  • Laterals
  • Complete Systems (Open and Closed)
  • Vacuum

Distinct Advantages

PE pipe provides several important benefits when used in sewer applications. These benefits include:
  1. Inflow and Infiltration (I & I) is totally eliminated, therefore minimizing the I & I in wet weather conditions on gravity flow systems.
  2. Total corrosion resistance.
  3. Cost-effective installation.

Sewer and Wastewater Application

There are several distinct advantages of PE pipe that provide important benefits for sewer and wastewater applications. These benefits are listed below.
  1. Heat Fused Joints – Benefits
    • HDPE pipe’s fused joints do not leak, eliminating infiltration and inflow problems experienced with alternate pipe joints.
    • HDPE pipe can be heat fused together to form a joint that is as strong or stronger than the pipe itself and is leak-free. This eliminates the potential leak points every 10-20 feet as found with PVC and Ductile Iron bell-and-spigot connections.
    • The Life Cycle Cost of HDPE pipe differs from other pipe materials because the “allowable water leakage” is zero rather than typical leakage rates of 10 to 20% for PVC and Ductile Iron.
    • HDPE pipe fused joints are self-restraining and do not require costly thrust restraints or thrust blocks.
  1. Chemical Resistant – Benefits
    • PE is highly resistant to the wet, hydrogen sulfide gas and the low concentration acid found in a sanitary sewer.
    • PE pipe will not corrode, tuberculate or support biological growth
    • To review information on PE’s resistance to various chemicals. (TR-19/2000)
    • Superior chemical resistance to aggressive soils.
  1. Abrasion Resistant – Benefit
    • PE is abrasion resistant and is well suited for the solids environment in sewer applications.
  1. Construction Advantages – Benefits
    • The combination of flexibility and leak-free joints allow for unique and cost-effective types of installation methods that the rigid PVC and Ductile Iron pipes can’t use with bell-and-spigot connections. These alternate installation methods (Horizontal Directional Drilling, Pipe Bursting, Sliplining, Plow and Plant, Submerged or Floating Pipe, etc.) can save considerable time and money in most applications.
    • Polyethylene pipe is produced in straight lengths up to 50 feet long and coiled in diameters up through 6 inches. Coiled lengths over 1,000 feet are available (depending on size) providing low cost installations.
    • Polyethylene is about one-eighth the density of steel and does not require the use of heavy lifting equipment for installation.
  1. Flexible and Fatigue Resistant – Benefits
    • HDPE pipe can be bent to a radius 25 times the nominal pipe diameter (Example: 12 inches of HDPE can be cold formed in the field to a 25-foot radius). This can eliminate many fittings required for directional changes in a piping system where fittings and thrust blocks or restraints are required with alternate materials.
    • The flexibility of HDPE pressure pipe makes it well suited for dynamic soils including areas prone to earthquake.
    • HDPE pressure pipe can accept repetitive pressure surges that significantly exceed the static pressure rating of the pipe.
  1. Cost Effective, Long Term and Permanent – Benefits
    • Polyethylene pipe installations are cost effective and have long-term cost advantages due to the pipe’s physical properties, leak-free joints and reduced maintenance costs.
    • The polyethylene pipe industry conservatively estimates the service life for HDPE pipe to be 50-100 years. This relates to savings in replacement costs for generations to come.
  1. Handling – Benefits
    • It is much easier to handle and install HDPE pipe vs. the heavier, rigid metallic or concrete pipe segments, allowing for huge cost advantages in the construction process.
    • Polyethylene pipe is better able to structurally withstand an impact than PVC pipe, especially in cold weather installations where other pipes are more prone to cracks and breaks.
  1. Hazen Williams C Factor is 150 and doesn’t change over time – Benefit
    • HDPE pipe has a smooth ID that does not corrode or tuberculate and maintains its flow capability over time.
    • The C Factor of Ductile Iron pipe is dramatically reduced over time due to corrosion and/or tuberculation.
Corroded Pipe

According to the Federal Highway Administration, utilities spend $36 billion annually on corrosion protection of pipes. Is your municipality contributing to these expenditures? If the answer is yes, then specify HDPE pipe. It does not corrode or tuberculate, long life-cycle reduces your maintenance budget, and infiltration into the pipe and exfiltration into the environment is non-existent.