Variable Length Tube (and Rod) Attributes

Model Reference Manual

Piping, Ducting and Cable Trays : Standard Component Attributes : Variable Length Tube (and Rod) Attributes

Straight lengths of Tube (ducting, trays and rod) between Components are not defined as elements in the hierarchy. Instead, they are extruded from the Leave p-point of a Component to the Arrive p-point of the next. Their geometric cross-section details are stored in the Catalogue and are pointed at from the Upstream Component via its LSTU attribute. At the Head of a Branch, there is no Upstream Component; therefore a special Branch attribute exists to allow Tube from the Head to the first Component to be specified (HSTU).

Generally, the user need not be concerned about specifying Tube between Components, as it is automatically determined during the Component Selection process described elsewhere. If short fixed-length stubs of Tube are required, it is usually appropriate to create a Component FTUB element to make sure that this minimum length is adhered to. Similarly, where Tube changes direction, a Component must be inserted (usually a BEND), as variable length Tube is always straight.


Examples:
LSTU /SPEC502/100L (At Branch Component)	The Tube between the Leave p-point of this Component and the Arrive of the Next (or Tail) is specified by the named Specification Component.
HST /SPEC502/100L (At Branch)	As above, but between the Head and Arrive of First Component (or Tail).
LSR /HS20/2.5 (At Hanger Component)	As first example.
HSR /HS20/2.5 (At Hanger Component)	As second example.

Note:

These attributes are usually set automatically when the CHOOSE (or SELECT) command is used.

Command Syntax:

>--+-- LSTube --.
   |            |
   |-- HSTube --|
   |            |
   |-- LSRod ---|
   |            |
   ‘-- HSRod ---+-- name ----.
                |            |
                ‘-- NULREF --+-->