NPSH Margin Table

The NPSH (Net Positive Suction Head) margin table is populated with values which are to be added to the calculated net positive suction head required (NPSHr) to control the "available" pumps in the selection process. The Selector also contains a user defined NPSH margin default  field in the conditions of service section. The Selector program uses the largest of the two values during the selection process.

To populate the NPSH margin table:

1. In the navigational tree, open the engineering data folder for the product line to edit.

2. Click on NPSH margin in the navigational tree. 

3. The data manager window will display the NPSH margin Table.

4. Enter a row rule.

5. Enter a column rule or rules.

6. Insert the numbers of columns needed to populate your data. Click here to see an example.

    

   

   NPSH Margin Table with two columns inserted

7. Select or manually enter rule criteria for the columns.

8. Enter data in the appropriate column-row cell relationship. See the below examples.

Important : Remember to assign the correct units of measure before entering data.

• Example 1 - NPSH Margin Table with pumps size and stages as the rule criteria.

   

  

  (Pump size and stages were selected from drop down selection boxes, the number of stages was manually entered).

  NPSH Margin Table with pump size and stages as rule criteria

  (pump size and stages were selected from drop down selection boxes, the number of stages were manually entered)

• Example 2 - NPSH Margin Table with pump size and max temperature as the rule criteria.

   

  

  (Pump size and max temperature were selected from drop down selection boxes, max temperature criteria was manually entered.)

  NSPH Margin Table with pump size, stages, and max temperature as rule criteria

  (pump size, stages, and max temperature wereselected from drop down selection boxes, temperature criteria and the number of stages were entered manually)

9. Click to save changes.