Dultmeier Sales: Flow Data - Water Through Hose

A technical page turned up in a Google search: Flow Data - Water Through Hose from Dultmeier Sales. One-page PDF. Some interesting facts. And it looks like it'll be useful if I can find it when I need it, and if I take a few minutes to figure it out.

Some of the interesting stuff:

Pressure loss is proportionate to length [of hose].

They include a table of pressure loss, too. And this:

Water pressure expressed as feet of head (height of a column, or difference in elevation) can be converted to psi by multiplying by .43.

Did not know that. (Won't remember it, either.) But it might come in handy when I run across a table that gives water pressure as "feet of head". I've seen it before.

And this:

Couplings of the insert type, attached with bands or clamps are restrictive. Pressure loss resulting from use of these couplings is approximately equal to 5% of the loss through 100’ of hose.

Using the table they provide(for 100' of hose) you can now figure the pressure loss from couplings. And this rings a bell for me.

When we decided to run a hose underground to our garden, I came across Installing an Underground Water Line and Remote Faucet from Lee Valley Tools. It encouraged me to go with my plan to bury the hose. So I did. In my heavy clay soil their "rock a spade handle back and forth" suggestion didn't work at all. But I got the digging all done in a day, enough to bury 223 feet of 3/4" hose.

One of their "points to keep in mind" was this:

Use a large-diameter hose and avoid the use of hose menders. The longer your hose, the greater the pressure drop is going to be between the faucet and the far end of the hose. The pressure drop is minimized by using large-diameter hose and by avoiding the use of restrictions such as hose menders.

It's a teaser. I went with their recommendation, obviously. But it stuck in my mind because I want to know what harm I'm doing to the flow by using a hose mender. Using the Dultmeier info sheet, maybe I can figure it out.