Hose barb adapter?

[BeezFun]

The suction side of my system includes a plastic pressure switch that has a 7/8" non barbed connection diameter, but the other side of the hose has to attach to a 3/4" metal barbed fitting. So I either need a hose barb adapter with 7/8" on one end and 3/4" on the other, or a specially made stub of hose that has two different diameters like plumbers use to attach dishwasher drain lines or garbage disposal lines. Any suggestions on the best way to do this? I've included photo of plastic switch and metal barb.

 

[Harry in Ky]

How long is that section of hose? That will affect the options available.

 

[BeezFun]

How long is that section of hose? That will affect the options available.

About 10" on each side of the switch.

 

[Harry in Ky]

Finding a step down hose would be difficult at best. I would most likely try to fab an adapter to put between the two, one side 7/8 the other 3/4. Short hose splices on each end.

I just went through a similar problem a week or so ago. You have to scrounge around and find the right size scraps of "whatever" to work with. Light steel tubing, copper pipe, maybe aluminum. Something you can weld, solder, braze, etc. In your case light 3/4 tubing can probably be fit into 7/8 tube and sealed up. I prefer using steel and brazing, but it depends on what I can find that fits.

 

[BeezFun]

I found a solution using some braided PVC tubing that has 3/4" ID but is more flexible than hydraulic suction hose so it will fit over the 7/8" plastic switch. I joined it with a 3/4" x 3/4" barb coupling:



Here's the whole thing put together:



The best news is I found the source of the suction air leak. I constantly have to bleed air from the system and I thought it was one of the hoses because they're 20 years old and badly abraded in some spots. But the problem was actually a fitting that either vibrated loose or someone forgot to tighten. It was finger tight so is likely the source of the air. The screwdriver handle points to the fitting:

 

[Williy]

You mentioned PVC pipe. I had to purchase
2 10 ft pieces of thin wall 4 inch PVC and 4
couplings $85+ I can remember purchasing
same in 20 ft lengths less than $10.

willy

 

[dstig1]

Replace the brass hose barb with one that is the same size as the other part. Then the hose fits both...

 

[Vigo327]

So im not against using that braided pvc stuff in hydraulic return lines and actually just installed some.. but be aware it has the same heat issues as the pvc pipe does.. its pressure handling goes WAAAY down at 200+f. Hopefully your system doesnt get too hot and your filter doesnt cause much backpressure and its a totally moot point, but its something to be aware of on the list of reasons of why pvc hose is not found more often in hydraulic return sections. Im not against it, but.. its conditional.

 

[BeezFun]

So im not against using that braided pvc stuff in hydraulic return lines and actually just installed some.. but be aware it has the same heat issues as the pvc pipe does.. its pressure handling goes WAAAY down at 200+f. Hopefully your system doesnt get too hot and your filter doesnt cause much backpressure and its a totally moot point, but its something to be aware of on the list of reasons of why pvc hose is not found more often in hydraulic return sections. Im not against it, but.. its conditional.

That's a good point. The hose I have is only spec'd up to 170F now that I look it up. In this case I think there's no way the system could reach over some small pressure because of the design of that black plastic pressure/flow switch. It doesn't have barbed ends, it's just smooth plastic. Even with the clamps as tight as I could get them I can pull the hose off by hand with a little twisting. I also made sure the braided hose is supported internally by a hose barb so there's no chance of it collapsing during suction. I'm not sure how they got the heavy original hoses on that switch. I used a heat gun until "real" suction hose was so hot I thought it would melt and still couldn't get it on the switch. Maybe they have some way to stretch the end of the hose to open it up enough to slide it on the switch.

Anyway I've tested it for quite awhile now and it seems to be holding with no leaks. So I'm calling it good.