FALLINGLINES

Function:

Defines the maximum rate of fall allowed in a pipeline before it is shown as a skew on the isometric plot.

Description:

Amounts of fall less than the current fall limit are shown by a wedge-shaped symbol on the pipe, together with a note giving the rate of fall. The wedge-shaped symbols are known as fall arrows. Amounts of fall greater than the current limit are shown as boxed skews. You can change the limit, and the units in which it is expressed.

Figure 2:4. Different ways of showing falling lines.

The default accuracy to which Isodraft will report the fall is as follows:

• Degrees to the nearest half degree

• Ratio to the nearest 1 up to 30; to the nearest 5 above 30

• Percentage to the nearest 1%

• Grads to the nearest half grad

• Metric inclination to the nearest 10mm per meter

• Imperial inclination to the nearest 1/16" per foot

  Note:
  That if the slope is less than 1:500 (or its equivalent in degrees, etc) the fall note will not be output.

You can specify different accuracy values for reporting the fall using the ACCURACYLEVEL value command (where value can be zero, 1 or 2). The accuracies you can specify are:

value (for each representation)

0

1

2

degrees

default

0.1

0.01

ratio

default

1 always

1 always

percentage

default

0.1

0.01

grads

default

0.1

0.01

metric

default

1mm/m

0.1mm/m

imperial

default

1/16"/10’

1/16"/100’

If you set an accuracy level and then wish to go back to the default settings, you must give an appropriate ACCURACYLEVEL command with a value of zero.

If the fall units are specified but the value of the fall limit is omitted, the following default values will be used. These correspond to approximately the same slope:

FALL DEG

will default to

FALL DEG 5

that means, 5 degrees

FALL RAT

will default to

FALL RAT 11

that means, a ratio of 1:11

FALL PER

will default to

FALL PER 9

that means, a slope of 9%

FALL GRA

will default to

FALL GRA 5

that means, 5 grads

FALL MET

will default to

FALL MET 80

that means, 80mm per meter

FALL IMP

will default to

FALL IMP 1

that means, 1/16 inch per foot

The overall default setting, if no fall units or limit are specified, is FALL DEG 5.

Where a falling section includes an in-line component, such as a Valve or Reducer, the FALL message will appear only once, against the first section of the slope. Where a falling section incorporates a Tee, the FALL message will be shown twice, on both sides of the Tee.

Figure 2:5. Falls in sections of pipe containing components.

Examples:

FALL RATIO 20

Sets fall limit to 1:20

FALL RATIO

Resets fall limit to ratio default of 1:11.

FALL PERCENT 2

Sets fall limit to 2%.

FALL PERCENT

Resets fall limit to percentage default of 9%.

FALL OFF

All falls shown as boxed skews; fall symbol not used at all.

FALL 1.4 DEG

Sets fall limit to 1.5 degrees.

FALL RAT 1:40

Sets fall limit to 1:40.

FALL PER 2.7%

Sets fall limit to 3% (to nearest per cent).

FALL GRAD 1.6

Sets fall limit to 1.5 grad.

FALL MET 30

Sets fall limit to a metric incline of 30mm/m.

FALL IMP 5/16"

Sets fall limit to an imperial incline of 5/16" per ft.

FALL MET 30 ACC 1

Sets fall limit to a metric incline of 30mm/m with a reporting accuracy of 1mm per meter.

Related Commands:

ANGLEACCURACY FALLSKEWS SKEWBOX ZEROLENGTHSKEWS

Command Syntax:

>- FALLinglines -+- DEG --------.
                 |              |
                 |- RATio ------|
                 |              |
                 |- PERcentage -|
                 |              |
                 |- GRAds ------|
                 |              |
                 |- IMPerial ---|
                 |              |
                 |- METric -----+- value --.
                 |              |          |
                 |              |          |- ACCuracylevel value -.
                 |              |          |                       |
                 |              ‘----------+-----------------------|
                 |                                                 |
                 ‘- OFF -------------------------------------------+->

Querying:

Q FALLinglines

Q OPTions