# Pressure Loss with Outlets

For estimating friction pressure losses or appropriate pipe sizes in pipelines with emitters (outlets) at regular intervals such as common in sprinkler or drip lines. Learn more about the units used on this page.

### Friction Loss from Laterals or Manifolds with Outlets

This calculates pressure loss due to friction in a pipe with regular equally spaced outlets, such as a sprinkler lateral, drip line, or a manifold.

Flow Rate In The Pipe:
Pipe Inside Diameter:
Number of Outlets:
Pipe Length:
Pipe Material:
Pressure Loss:

### Minimum Pipe Diameter Size

This calculates the minimum pipe size for a pipe with equally spaced outlets such as a sprinkler lateral or manifold given a maximum allowable pressure loss.

Flow Rate In The Pipe:
Maximum Allowable Pressure Loss:
Number of Outlets:
Pipe Length:
Pipe Material:
Minimum Pipe Diameter:

## The Equation

This calculator uses Christiansen's equation for a reduction coefficient F that is multiplied by the Hazen-Williams equation for pressure loss due to friction in a pipe with evenly spaced outlets. F is calculated as:

Where:

= Reduction Coefficient

= Number of outlets in the line

= Velocity or flow component of the headloss equation (1.852 in this case).

This is multiplied by the pressure loss (F X Ploss), where pressure loss is calculated by the Hazen-Williams formula:

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