Sufficient space for horizontal directional drilling machine (HDD) and support vehicle, preferably in line with existing replacement section, a horizontal distance commensurate with a turning radius not less than that recommended by the manufacturer, from the point of entrance of the borehead to the point of completion of the installed pipe plus 10 feet. Offsetting may be accomplished using the same radius constraints as physical surroundings dictate.

One insertion pit location approximately 30 feet (the actual length varies with depth) in length for each "run" of replacement pipe. Insertion pits may be located over manholes scheduled for replacement thereby reducing excavation costs.

Determination of maximum length per installation section by review of machine capacity and/or selection, consideration given to type of in-place pipe, replacement pipe size, sub-surface conditions, relief locations, and retrieval capacity.

INSPECTION OF EXISTING SYSTEMS

Perform television inspection of existing system. Review tape and determine extent of line damage, location of steel or cast iron repairs, extent of grade variance, size and location of service laterals. See also Sample Specifications and Installation Guide.

• Trenching and backfill minimized
  
  
• Surface structure demolition and restoration minimized or eliminated
  
  
• Minor "sags" require no prior repair
  
  
• Substantial Elimination of Bedding Materials
  
  
• Existing utilities exposed to damage by an open cut installation will remain undisturbed.
  
  
• Business losses minimized
  
  
• Safety Hazards greatly reduced
  
  
• Negative public reaction reduced
  
  
• Traffic interference reduced
  
  
• "Unit" installation reduces worker errors.

• HDPE, SDR(xx), fusion welded. SDR determined by engineer
  
  
• Restrained Joint PVC, SDR (xx), such as CertaLok™, Yelomine™, CertaLok C900, manufactured by Certain Teed Corporation or Aquamine™, manufactured by Aquamine, LLC.
  
  
• Fusible PVC by Underground Solutions, Inc
  
  
• Restrained Joint Ductile Iron manufactured by US Pipe, American Cast Iron Pipe, and Griffin Pipe Products.
  
  
• The types listed are the preferred materials for this type of installation, each having distinct chemical and physical characteristics that together provide adequate selection for excellent project performance

• Standard saddles and fittings for PVC and restrained joint ductile iron (Various manufacturers)
  
  
• Inserta Tee™ for HDPE and PVC (Inserta Fittings Company)
  
  
• Electrofusion saddles and fittings (Manufactured by Central Plastics & Friatec)
  
  
• Fusion fittings and saddles (Manufactured by Driscopipe, Central and others)