Corrugated Stainless Steel Pipe

[WorldPeace]

I noticed retailers recommending a corrugated stainless steel pipe connection to the water softener. Something like this:

Falcon Stainless Steel Flex Connectors, Buy Industrial & Commercial Water Softener Online

Stainless steel flex connectors make it easy for water softener installation. Another reason is hard pipe installations are more expensive, time consuming and often times difficult to maneuver. Flex connectors saves time and saves money!

www.isopurewater.com

I'm wondering about the pros and cons.

On the one hand:
- I've read that corrugated piping usually leads to trubulence, and pressure drops by 150%.

On the other hand:
- Over such a short length of piping, 150% of something small would be insignificant.
- Flexible piping would make it extremely convenient to connect and disconnect the water softener.

However, would you ever really need to disconnect it? When you need to replace the resin every 10-15 years?

But is there any appreciable water pressure drop to the entire house by using this flexible connection as opposed to a direct pex connection?

 

[Reach4]

I've read that corrugated piping usually leads to trubulence, and pressure drops by 150%.

That sounds 150% impossible to me.

Those connectors are bigger ID than most flex connectors, and they will have lower pressure drop.

Braided stainless steel connectors are really rubber/plastic tubes with the braid only a covering.

 

[Sponsor]

 

[Breplum]

No pressure drop...actually NONE. Un-measurable friction over short distances.

 

[John Gayewski]

Corrugated stainless steel tubing does have a much higher pressure drop than smooth piping. This is mostly measured and considered for gas piping where long runs of pipe and pressure drop can make a big difference at such low pressures within gas systems.

 

[MaxBlack]

...Braided stainless steel connectors are really rubber/plastic tubes with the braid only a covering.

This. Well, I haven't seen every hose on the planet but have always believed this.

 

[WorldPeace]

That sounds 150% impossible to me.

Those connectors are bigger ID than most flex connectors, and they will have lower pressure drop.

Braided stainless steel connectors are really rubber/plastic tubes with the braid only a covering.

I'm sorry if I wasn't clear. I was trying to say that the pressure drop in corrugated piping is 150% of the pressure drop in stainless steel. For example, if the pressure drop in 10 ft of a stainless steel pipe section is 5 PSI, then the pressure drop in the corrugated piping would be 7.5 PSI.

This is what was reported so I don't know what would actually happen here. From what people are saying here is that the pressure drop in such a short section would be negligible.

 

[Reach4]

I'm sorry if I wasn't clear. I was trying to say that the pressure drop in corrugated piping is 150% of the pressure drop in stainless steel. For example, if the pressure drop in 10 ft of a stainless steel pipe section is 5 PSI, then the pressure drop in the corrugated piping would be 7.5 PSI.

When you say "stainless steel pipe", what do you mean. Nobody uses actual stainless steel pipe to connect to a softener. If you mean the braided stainless steel connector lines, I expect the nominal 1 inch Falcon connector to have less drop than a typical nominal 1 inch braided connector line of the same length due to the actual ID difference. Your typical braided connector does not even specify the ID.

10 gpm through a home softener would be unusually high. A flexible connector line is normally not longer than 2 ft.

 

[WorldPeace]

When you say "stainless steel pipe", what do you mean. Nobody uses actual stainless steel pipe to connect to a softener. If you mean the braided stainless steel connector lines, I expect the nominal 1 inch Falcon connector to have less drop than a typical nominal 1 inch braided connector line of the same length due to the actual ID difference. Your typical braided connector does not even specify the ID.

10 gpm through a home softener would be unusually high. A flexible connector line is normally not longer than 2 ft.

I'm going off on my memory so I might be wrong but the research study used steel pipe (I added stainless). I think they meant piping that had smooth walls. I added stainless because I assumed that was the smoothest. (Although it's not relevant here, but my understanding that stainless steel is the best for domestic water but most people don't use it though because of the price.)

 

[Reach4]

I'm going off on my memory so I might be wrong but the research study used steel pipe (I added stainless). I think they meant piping that had smooth walls. I added stainless because I assumed that was the smoothest. (Although it's not relevant here, but my understanding that stainless steel is the best for domestic water but most people don't use it though because of the price.)

A better comparison would be copper. Another good comparison would be PEX, but it is probably not as flexible as you picture it if you have not worked with PEX. The ID of 1 inch PEX is 0.875 inch. But it is smooth. The cross sectional area of a 1 inch Falcon connector would be about 30% larger, which I suspect would make up for the corrugation aspect.

From https://www.hosemaster.com/technical-information-flexible-metal-products/pressure-drop/

Would you say this topic is more practical or academic to you? If practical, you worry too much about this. A 12 inch softener only takes 3.5 gpm during backwash.

 

[WorldPeace]

Would you say this topic is more practical or academic to you? If practical, you worry too much about this. A 12 inch softener only takes 3.5 gpm during backwash.

You're completely right. I worry too much in terms of practical usage. As you can tell, I'm sorta' a perfectionist (in a very bad way). I need to make sure everything is perfect or I can't let it go. I'm sorta' sick in the head. 2 of my friends are asking me to recommend a specific water softener setup, and I was afraid to steer them wrong. I didn't want to look stupid.

I installed my water softener myself, and I used Pex A to connect the water supply directly to the water softener because I was worried about the pressure drop. But it was a major pain in the ass because the water softener is heavy and not very mobile; it doesn't have a lot of give. I'd probably go for a flexible connection in hindsight given your chart (which shows that I was worried about nothing).

Based on your chart, if you assume a fluid velocity of about 10 GPM, then your chart indicates a pressure drop of .6 PSI (.4 PSI x 1.5 ft of piping) for the corrugated. And a pressure drop of .27 PSI (.18 x 1.5 ft of piping) for Pex.

This is a 122% difference in pressure drop between corrugated and flexible (which is similar to the 150% estimate for corrugated and rigid). But, in terms of overall pressure difference, I guess .33 PSI is pretty negligible for the sake of convenience during installation?

Even if we assume a maximum fluid velocity of say 15 GPM, the total pressure drop difference might be .6 PSI if all the fixtures were turned on at once.

I don't know if my calculations are correct but it looks like I was worried about nothing. .6 PSI is something but not much when you consider PSI can get to 40 PSI.

Thanks for the info!