WASTAGE AREA

Function:

Defines wastage areas which can be given different wastage factors for cut pipe lengths.

Description:

When cut pipe lengths are calculated, Isodraft can include extra material to allow for wastage during cutting and fabrication. A complete Plant can be split up into a maximum of ten wastage areas, numbered 0 to 9, and each wastage area can be allocated a wastage factor.

• Default values for the wastage factors for areas 1‑9 are all 1.

• The wastage factor for area 0 is fixed at 1 (that is, no wastage allowance).

Isodraft uses the wastage factors to modify the cut pipe lengths as follows:

• In the DESIGN database, the EREC attribute for a pipe branch can be set to an integer, which corresponds to the wastage area for all tube in the Branch. EREC=10 is treated as area 0, EREC=11 is treated as area 1, and so on.

• Each tube item may have, included in its Specification, a standard wastage allowance (PWAS) in the form of an added percentage.

• When calculating a cut pipe length, Isodraft multiplies the standard wastage allowance (PWAS) for the appropriate type of tube by the wastage factor for the area in which the length occurs (determined by the EREC for the branch).

• The corrected percentage allowance thus calculated is then added to the nominal length of the pipe to give the cut length which is plotted on the drawing.

  Note: A cut pipe list is only output if the user has given the CUTTINGLIST command.

Examples:

Consider a length of pipe connecting two components whose separation measured along the pipe centreline is 1000mm. Assume that the tube specification has PWAS set to 10; that is, a 10% allowance is preset. Assume that the pipe length forms part of a branch for which the EREC attribute has been set to 3. Assume that the wastage factor for wastage area 3 has been set to 1.2 by using the command.

WASTAGE AREA 3 1.2

Then the wastage allowance calculated by Isodraft will be (1000 x 10% x 1.2) mm, that is, 120mm, and the cut pipe length given on the isometric will be 1120mm.

Command Syntax:

.-------------<----------.

/ |

>--- WASTage ---*--- ARea integer value ---+--->

Restrictions:

Isodraft only includes a wastage allowance if WASTAGE AREA has been set. The default is for no allowance, even if PWAS has been set.

Querying:

Q WASTage shows value for the area number queried

Q WASTage integer

Q OPTIONS