curl --request POST \
  --url https://api.iotools.cloud/v1/tool/npsh-available-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "unitSystem": "si",
  "atmosphericPressure": "101.325",
  "vaporPressure": "2.339",
  "specificGravity": "1.0",
  "staticSuctionHead": "2",
  "frictionLossSuction": "1.2"
}
'

{
  "tool": "npsh-available-calculator",
  "tool_version": "1.0.2",
  "outputs": {
    "results": [
      {
        "metric": "Source pressure head (Ha)",
        "value": "10.332 m"
      },
      {
        "metric": "Vapor pressure head (Hvp)",
        "value": "0.239 m"
      },
      {
        "metric": "Static suction head (Hs)",
        "value": "2.000 m"
      },
      {
        "metric": "Suction friction loss (Hf)",
        "value": "1.200 m"
      },
      {
        "metric": "NPSH available (NPSHa)",
        "value": "10.894 m"
      }
    ],
    "summary": "NPSHa = 10.89 m (positive margin)"
  },
  "credits_used": 5,
  "credits_remaining": null
}