3D Pointsets (PTSET)

A PTSET is a collection of P-point elements. P-points are used in the design process to position and orientate Piping Components, and to define their connectivity to each other. P-points may also be used in PARAGON to define the position and orientation of the 3D Geomset primitives which make up Piping Components, Joints and Fittings. (Profiles do not use P-points.)

A P-point has a 3D position and a direction, and is identified by a number. Each PTSET includes a special P-point, P-point zero (P0), whose position is the component origin and whose direction is the Z axis direction of the Component. It has no other attributes. P0 is created automatically by PARAGON; you cannot change it in any way.

The numbering of the P-points of Piping Components must follow certain conventions - see Piping Components in PARAGON for a summary of these, and the Isodraft Reference Manual for fuller details. There are no special conventions for numbering the P-points of Joints and Fittings.

A P-point has a connection type attribute, which is used only when the P-point belongs to a Piping Component. The connection type attribute can be used to specify how a Piping Component is connected to another at the position of the P-point, for example by a butt weld or socket weld.

A P-point has a bore attribute, which is used only when the P-point belongs to a Piping Component. It can be used to specify the bore of the pipe at that point.

PDMS’s data consistency checks (refer to the Design Reference Manual) can be used to check that the connection type attributes of Piping Components are compatible with the corresponding attributes of the Components to which they are connected. The compatibility of connection types is defined in a Connection Compatibility Table (CCTAB) - see Connection Compatibility Tables for further information.

Use of the REPRESENTATION command affects how P-points are drawn by PARAGON; see P-point and P-line Representation for further information.

A PTSET has the following attributes:

• DESC - a textual description of the Pointset

• GTYP - the generic type of the item for which the Pointset is used

• SKEY - the Symbol Key to which the Pointset relates (refer to the Isodraft Reference Manual)

• PURP - the purpose of the Pointset

A PTSET may contain one or more of the three types of P-point element:

• Axial P-point - PTAXI

• Cartesian P-point - PTCAR

• Mixed P-point - PTMIX