 # Engineering Bulletin

## Calculation of Pressure Loss in Corrugated Hoses

Corrugated metal hoses are used for conveying substances of different consistency (gaseous, liquid or solid). One of the important factors to consider in designing systems that implement metal hoses is the loss of pressure. Due to its profile, the pressure loss in corrugated hoses is significantly higher than in steel pipes,  almost 100% and about 20% to 25% higher for the stripwound hoses.

To calculate pressure loss in corrugated hoses, use the Pressure Loss graph below. For example: we need to calculate the pressure loss in corrugated hoses 85 feet long and 2″ in inner diameter (ID) which transfer water with flow rate of 1400 cubic feet per hour. By using calculator below we find that 1400 ft3/hour corresponds to 175 gal/min. Then we plot the 175 gpm on the X-axis of the chart below until we “hit” the line for 2″ hose ID, then by going over horizontally to the Y-axis, we find that Pressure Loss per foot of hose will be about 3.7 psi. So that the total pressure drop over the hose length will be 314.5 psi (3.7 x 85).

Keep in mind that if you transfer gaseous substance through the hose then you need to find the ratio of the density of gas over the density of water and adjust the pressure drop respectively. For example if you transfer natural gas (density = 0.050 lb/ft3) and knowing that water density = 62.4 lb/ft3 we can find out the pressure drop as the following: 3.7 x (0.050/62.4) = 0.0030 psi/ft or 0.255 psi for entire length of hose (85 x 0.003).