Generate Envelope File - PDS - Help

Plant Design System (PDS) Equipment Modeling (PD_EQP)


This command generates an interference envelope file from the current design file. The system gives the envelope file the same filename as your design file but with the .env extension for the types of envelopes switched on and writes those files to the same directory that contains the equipment models. By default, all types are on. (Refer to the PDS Piping Design User's Guide for information on running interference detection.)


  • Physical — Defines the actual equipment including components such as nozzles, supports, etc.

  • Maintenance (hard/soft) — Defines the space required to access equipment for repairs and maintenance. For example, when repairing tubing in a heat exchanger there must be enough space between the heat exchanger and the next piece of equipment to allow you to pull the tubing out of the shell.

  • Access (hard/soft) — Defines the areas of space for personnel access including thru-ladders, catwalks, etc.

  • Safety (hard/soft) — Defines the safety clearances around equipment and/or creates envelopes on safety equipment. For example, a safety envelope can define an area around a high temperature vessel.

  • Construction (hard/soft) — Defines an area around a component in a specified discipline. When two components are closer than the allowable tolerance (defined in the Project Administrator [PD_PROJ]), a clash is flagged.

  • Light Steel — Defines envelopes around equipment defined as light steel, such as ladders, platforms, handrails.

  • Attached Graphics — Defines envelopes generated on semi-intelligent graphics such as an MCE graphic attached to a tank.

  • Insulation — Defines an area occupying insulation space around a piece of equipment.

    It is recommended that you generate envelope files (.env files) with the envelope generating facility in PD_Clash. This is because the .env file will be out of date when you exit the equipment file and as a result, will have to be generated by PD_Clash anyway.