CUTBACK

Function:

Allows the user to make sure, there is sufficient length between a pulled bend and the end of the pipe to be gripped by the bending machine, and that a pipe with a threaded end is long enough to be gripped by the threading machine.

Description:

This command adds length to a cut pipe, where necessary, which will be cut back after the fabrication work is finished. Additional length will be added to cut pipes when either of the following conditions is met:

• The length between a pulled bend and the end of the pipe is insufficient to allow the bending machine to grip the pipe.

• The length of a pipe that is to have a threaded end is insufficient to be gripped by the threading machine.

The software checks the distance between the p-arrive or p-leave of the pulled bend and the start or end of the pipe (or the length of the pipe to be threaded). If this distance is found to be less than the minimum grip length, the length of pipe required to give this length is added to the total length of the cut pipe.

Note: If two adjacent bends are closer than the minimum grip length, then a warning message is written into the message file.

The ATEXTs 186 (CUT START) and 187 (CUT END) are output to the remarks column of the Cutting List’ on the isometric, or to the ‘Special Req.’ column of the ‘Cut Pipe List File’, when appropriate.

The minimum grip length required to handle these pipes successfully depends on a number of factors, such as bore size, pipe material, or type of machine. To handle these varying factors, AVEVA E3D Design rules are used.

Examples:

CUTBack 150 ON ALL BEND WITH (SPREF EQ/name)

This associates the minimum grip length with catalogue data.

CUTB 2 INCH ON ALL BENDS WITH (ABOR GE 100 AND ABOR LT 200)

This sets a minimum grip length of 2 inches for all bends in pipes with bores between 100 and 200mm.

CUTB 200 ON ALL BEND

This syntax can be used as the last rule or a catch all to make sure that all bends have at least a 200mm grip length.

Note: At a bend, Isodraft will use the first rule it finds for which the expression is TRUE. Therefore, the order of the rules is important.

CUTBack 175 ON THREAD

This makes sure that any cut pipe with a threaded end is always at least 175mm in length.

Command Syntax:

>- CUTBack -+- value ‑ ON -+- ALL BEND -+- WITH - (logical expression) -.
            |              |            |                               |
            |              |            ‘-------------------------------|
            |              |                                            |
            |              ‘- THREADedends -----------------------------|
            |                                                           |
            ‘- NONE* ---------------------------------------------------+->

value is the minimum grip length. It may be input in mm or inches.

logical expression may be any logical PML expression, from the ‘PML 1 Expression Handler’. For more details, refer to PML Expressions. This syntax may be used repeatedly to build up an unlimited number of rules.

Querying:

Q CUTBack

Outputs a list of defined cutback rules or ‘none’ if no rules are defined.

Q CUTBack RULE COUNT

Outputs the number of cutback rules that have been defined.

Q CUTBack RULE <int>

Outputs the rule identified by the <int> number.