Keyword *DIAM

This keyword is used to define the pipe directory used for dimensioning of one or more pipes. This keyword must come before the pipe keyword.

FORMAT:

*DIAM           <krit1 krit2 LIM “typ”

“typ1”  d1  v1  k1 

“typ2”  d2  v2  k2

.     .    .   .

“typ20” d20 v20  k20 >

 

Where:

krit1:            is the velocity criterion in m/s.

krit2:            is the gradient in Pa/m.

LIM:             is the pipe diameter in mm below which the velocity criterion

and above which the gradient are to be applied.

Typ:             The default pipe type is used for a possible flow route

through a ring connection. The dimension is used only when all pipes in a ring connection have unknown dimensions. In this case, the type will be specified as “typ” regardless of the dimensioning criterion. The possible flow route is indicated by * in the input data element of the printout.

typ1:            name of the pipe type (max. 8 characters enclosed in inverted commas)

d1:               the internal diameter for the pipe type (mm)

v1:               heat transfer coefficient (W/(°C × m))

k1:               roughness for the pipe type (mm)

This list may include up to 20 different pipe types. If fewer than 20 types are specified, the table must be ended with a “/” (slash).

Note that if e.g. the velocity criterion (1 m/s) is to be used for all diameters, krit1, krit2 and LIM must be 1.0, * and * respectively. Similarly, if the gradient criterion of 103 Pa/m is to be used for all diameters, krit1, krit2 and LIM must be *, 103.0 and * respectively.

Example:

*DIAM Velocity criterion   3.0   m/s

      Gradient criterion   1.0   Pa/m

      Limit                      75.0   mm

      Default pipe type  “N200”

      Type      I.Diam    v          k

      -----------------------------------

      “N050”     48.7     0.330      0.05

      “N100”     89.3     0.350      0.05

      “N125”    114.7     0.320      0.05

      “N150”    156.8     0.340      0.05

      “N200”    189.6     0.550      0.05

      “N250”    215.4     0.440      0.05

      “N300”    313.4     0.550      0.05

 /