Orifice Head Loss
Orifice head loss is the pressure drop or decrease in fluid pressure caused by the presence of an orifice plate in a pipeline. It occurs due to the reduction in the flow area of the pipeline caused by the orifice plate, which results in increased fluid velocity and turbulence. The amount of head loss depends on several factors such as the size and shape of the orifice plate, the Reynolds number of the fluid flow, and the viscosity of the fluid.
Horizontal Orifice and Nozzle Head Loss formula |
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| \(\large{ \Delta h = \frac{1}{2\;g} \; \left( 1 - \beta^4 \right) \; \left( \frac{ Q }{ C_d \; A_o \; Y } \right)^2 }\) | ||
| Symbol | English | Metric |
| \(\large{ \Delta h }\) = head loss | \(\large{ ft }\) | \(\large{ m }\) |
| \(\large{ g }\) = gravitational acceleration | \(\large{\frac{ft}{sec^2}}\) | \(\large{\frac{m}{s^2}}\) |
| \(\large{ \beta }\) (Greek symbol beta) = ratio of pipe inside diameter to orifice diameter | \(\large{ dimensionless }\) | |
| \(\large{ Q }\) = orifice flow rate | \(\large{\frac{ft^3}{sec}}\) | \(\large{\frac{m^3}{s}}\) |
| \(\large{ C_d }\) = orifice discharge coefficient | \(\large{ dimensionless }\) | |
| \(\large{ A_o }\) = orifice area | \(\large{ in^2 }\) | \(\large{ mm^2 }\) |
| \(\large{ Y }\) = expansion coefficient (Y = 1 for incompressible flow) | \(\large{ dimensionless }\) | |
Solve for: |
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\(\large{ Y = \frac{ C_{d,c} }{ C_{d,i} } }\) \(\large{ C_{d,c} }\) = discharge coefficient compressible fluid \(\large{ C_{d,i} }\) = discharge coefficient incompressible fluid \(\large{ \beta }\) (Greek symbol beta) = \(\frac{d_0}{d_u}\) \(\large{ d_o }\) = orifice or nozzle diameter \(\large{ d_u }\) = upstream pipe inside diameter from orifice or nozzle |
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Vertical Orifice and Nozzle Head Loss formula |
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| \(\large{ \Delta h = \frac{1}{2\;g} \; \left( 1 - \beta^4 \right) \; \left( \frac{ Q }{ C_d \; A_o \; Y } \right)^2 - \Delta y }\) | ||
| Symbol | English | Metric |
| \(\large{ \Delta h }\) = head loss | \(\large{ ft }\) | \(\large{ m }\) |
| \(\large{ ft }\) | \(\large{ m }\) | |
| \(\large{ g }\) = gravitational acceleration | \(\large{\frac{ft}{sec^2}}\) | \(\large{\frac{m}{s^2}}\) |
| \(\large{ \beta }\) (Greek symbol beta) = ratio of pipe inside diameter to orifice diameter | \(\large{ dimensionless }\) | |
| \(\large{ Q }\) = orifice flow rate | \(\large{\frac{ft^3}{sec}}\) | \(\large{\frac{m^3}{s}}\) |
| \(\large{ C_d }\) = orifice discharge coefficient | \(\large{ dimensionless }\) | |
| \(\large{ A_o }\) = orifice area | \(\large{ in^2 }\) | \(\large{ mm^2 }\) |
| \(\large{ \Delta y }\) = elevation change (\(\Delta y = y_1 - y_2\)) | \(\large{ dimensionless }\) | |
Solve for: |
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\(\large{ Y = \frac{ C_{d,c} }{ C_{d,i} } }\) \(\large{ C_{d,c} }\) = discharge coefficient compressible fluid \(\large{ C_{d,i} }\) = discharge coefficient incompressible fluid \(\large{ \beta }\) (Greek symbol beta) = \(\frac{d_0}{d_u}\) \(\large{ d_o }\) = orifice or nozzle diameter \(\large{ d_u }\) = upstream pipe inside diameter from orifice or nozzle |
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