Pipeline to Pipeline spacing

The minimum spacing for underground pipelines may depend on a number if issues.
Excavation for visual inspection:
- The minimum distance between the outside diameter of two adjacent pipes should be shovel width = 12" (300mm)

Inspection via electronic "Pig":
- Contact the Pig suppliers to find out if there is a minimum distance criteria between two adjacent pipelines

Installation Contractor/method criteria
- Consult with the Installation Contractor to determine if the installation method will require a specific minimum spacing

Client preference:
- Question the Client to determine if they have any specific preferences

Good Engineering judgement:
- Question people with experience who have done this before

Material of construction for the piping will also be a consideration.

HDPE, for example, will require more room for growth / expansion than carbon steel.