{
  "title": "Ridgeline P1 selected tube pressure-loss reference",
  "publisher": "Ridgeline Tubes Limited",
  "source_url": "https://ridgelinetubes.com/wp-content/uploads/2026/06/Ridgeline-Plumbing-P1-Data-Sheet.pdf",
  "source_revision": "Rev 2, July 2026",
  "source_page": 4,
  "source_sha256": "c0cc5c5c8096712d374b3b231bdccd9862a53bcbf9cc6a842682f580649f3892",
  "transcription_checked_on": "2026-09-27",
  "units": {
    "flow_l_min": "L/min",
    "pressure_loss_pa_m": "Pa/m",
    "velocity_m_s": "m/s"
  },
  "scope": "Selected published tube values, not a complete circuit calculation or a new independent test. Fluid, temperature and test/calculation conditions are not stated alongside the source table; confirm applicability before design use. No interpolation or extrapolation is supplied. R-28 is included as a reference comparison, not a heat-pump size recommendation.",
  "reference_page": "https://ridgelinetubes.com/technical-guides/pipework-for-air-source-heat-pumps/#published-tube-loss-reference",
  "rows": [
    {
      "size": "R-28",
      "flow_l_min": 10,
      "pressure_loss_pa_m": 225,
      "velocity_m_s": 0.4
    },
    {
      "size": "R-32-HP",
      "flow_l_min": 10,
      "pressure_loss_pa_m": 95,
      "velocity_m_s": 0.29
    },
    {
      "size": "R-35",
      "flow_l_min": 10,
      "pressure_loss_pa_m": 33,
      "velocity_m_s": 0.19
    },
    {
      "size": "R-28",
      "flow_l_min": 15,
      "pressure_loss_pa_m": 500,
      "velocity_m_s": 0.6
    },
    {
      "size": "R-32-HP",
      "flow_l_min": 15,
      "pressure_loss_pa_m": 211,
      "velocity_m_s": 0.44
    },
    {
      "size": "R-35",
      "flow_l_min": 15,
      "pressure_loss_pa_m": 73,
      "velocity_m_s": 0.29
    },
    {
      "size": "R-28",
      "flow_l_min": 20,
      "pressure_loss_pa_m": 885,
      "velocity_m_s": 0.8
    },
    {
      "size": "R-32-HP",
      "flow_l_min": 20,
      "pressure_loss_pa_m": 373,
      "velocity_m_s": 0.58
    },
    {
      "size": "R-35",
      "flow_l_min": 20,
      "pressure_loss_pa_m": 128,
      "velocity_m_s": 0.39
    },
    {
      "size": "R-28",
      "flow_l_min": 25,
      "pressure_loss_pa_m": 1378,
      "velocity_m_s": 1.0
    },
    {
      "size": "R-32-HP",
      "flow_l_min": 25,
      "pressure_loss_pa_m": 580,
      "velocity_m_s": 0.73
    },
    {
      "size": "R-35",
      "flow_l_min": 25,
      "pressure_loss_pa_m": 199,
      "velocity_m_s": 0.49
    },
    {
      "size": "R-28",
      "flow_l_min": 30,
      "pressure_loss_pa_m": 1981,
      "velocity_m_s": 1.2
    },
    {
      "size": "R-32-HP",
      "flow_l_min": 30,
      "pressure_loss_pa_m": 833,
      "velocity_m_s": 0.87
    },
    {
      "size": "R-35",
      "flow_l_min": 30,
      "pressure_loss_pa_m": 285,
      "velocity_m_s": 0.58
    }
  ],
  "reference_version": "1.0",
  "reference_published": "2026-09-27",
  "description": "Fifteen selected tube pressure-loss and velocity values for Ridgeline R-28, R-32 HP and R-35 at 10, 15, 20, 25 and 30 L/min, transcribed from the P1 Technical Data Sheet, Rev 2, July 2026, page 4. Selected published tube values, not a complete circuit calculation or a new independent test. Fluid, temperature and test/calculation conditions are not stated alongside the source table; confirm applicability before design use. No interpolation or extrapolation is supplied. R-28 is included as a reference comparison, not a heat-pump size recommendation."
}