Strainer selection:
Perfectt Engineers have observed that to keep the pressure drop within reasonable limits and to have effective straining it is necessary that the free straining area will be a least three times the pipe cross sectional area in the case of Y - Strainers and six times in the case of Basket type strainers.
Select the anticipated clogging % at the left of the chart. The example shows a basket 75% clogged. Then, follow that until the curve is intersected. From that point follow downward to the scale along the bottom to read the pressure drop multiplying factor, in this case 4. The resulting pressure drop across the basket at 75% clogged is four times as great as that for a clear basket.
Example: How much is the Pressure drop through a 12” Y” strainer for a flow of 1000 GPM of water at ambient temperature with 1/8” perforated basket which is 75% clogged? Find the pressure drop for a clean basket from the curve. At 1000 GPM it is 0.3 psi. As prescribed, the multiplying factor for a 75% clogged basket is 4. The pressure drop is then 03.psi x 4 = 1.2 psi.
Select the anticipated clogging % at the left of the chart. The example shows a basket 75% clogged. Then, follow that until the curve is intersected. From that point follow downward to the scale along the bottom to read the pressure drop multiplying factor, in this case 4. The resulting pressure drop across the basket at 75% clogged is four times as great as that for a clear basket.
Example : How much is the Pressure drop through a 12” Basket strainer for a flow of 2500 GPM of water at ambient temperature with 1/8” perforated basket which is 75% clogged? Find the pressure drop for a clean basket. At 2500 GPM of water the pressure drop is 0.2 psi. As described, the multiplying factor for a 75% clogged basket is 4. The pressure drop is then 02.psi x 4 = 1.8 psi. |