Pressure Drop In a Jetter Hose

In our article about choosing the right sewer jetter hose, we talked about how the diameter of your jetter hose can have a big impact on the effort needed to clean a drain. Larger diameter hoses are less flexible and move less easily through dirty sewer pipes. Too small a diameter can overload your pressure washer.

How do you choose the right diameter of sewer jetter hose? That depends on the GPM and PSI rating of your pressure washer and your required length of sewer jetter hose.

To choose the right diameter for a 100 foot sewer jetter hose:

1. Find the GPM column heading in the following table that’s equal to or greater than the flow rating of your pressure washer.
2. Look down the column until you see a pressure drop that’s well below half of your machine’s PSI pressure rating.
3. Find the corresponding hose diameter (ID) in the far-left column of the row.

Pressure Drop (PSI) Per 100 Foot of Jetter Hose

Jetter Hose ID	1.5 GPM	2.0 GPM	2.5 GPM	3.0 GPM	3.5 GPM	4.0 GPM	4.5 GPM	5.0 GPM
1/8″	2,360	3,988	6,001	8,397	11,175	14,333	17,870	21,786
3/16″	332	556	829	1,151	1,523	1,943	2,410	2,926
1/4″	83	139	207	286	377	479	593	718
5/16″	29	48	71	98	128	163	201	243
3/8″	12	20	29	41	54	68	84	101

© 2009-2014 by Clog Hog. Used by permission.

Note: you can find the pressure drop in 200 feet of line by doubling the PSI values in the table. For 50 feet of line, use half the PSI values.

To avoid overloading your pressure washer, choose a nozzle that produces no more than the PSI pressure rating of your machine, minus the pressure drop the hose, at your machine’s GPM flow rating. You should also account for the manufacturing tolerances of different grades of nozzles, as discussed in our article about choosing the right sewer jetter nozzle.

Before building a sewer jetter compare the cost of buying, shipping and assembling the components yourself to the price of a ready-to-use sewer jetting drain cleaner that’s custom-fitted for your pressure washer.