How attach 1.5" waste hose to PVC tube?

[rwidman]

It would not be wise to glue hose onto pipe. The hose will need to be replaced at some point.

Clamps are the best way to secure the hose to the pipe and still allow the hose to be replaced.

[dave777]

Originally Posted by fallingeggs

I had a very similar quest, but for a 1'' holding tank vent hose going to a 1'' PVC installed in the tank via a Uniseal.

I found this guy, which I think will work...

https://flexpvc.com/cart/agora.cgi?p...n&ppinc=detail

Mine (a 1" slip socket by 1" barb) hasn't arrive for me to verify, but it seems promising.


Sent from my iPhone using Cruisers Sailing Forum

This looks like a case of knowing the terminology. At that retailer "Slip & barb" lead me to find "Compression & socket" at Lowes. Inexpensive solution that I don't have to wait for mail order, and can dry fit in the store.

Thanks!

[peghall]

I stand corrected...thanks! And fittings are yet a third category! However, that raises a question (I'm not too old learn something yet!):

If pipe sizes are stated OD, then why wouldn't a 1.5" pipe be the right fit for a 1.5" hose? That it apparently wasn't is what prompted my comment, which drew a reply that 1.25" pipe has an OD of 1.66".... I'm confused!

[phydeaux]

Here's a quick solution from Forespar, who make Marelon plumbing



From Art Bandy…………………………….. Use #901014 female NPSM to 1-1/2" barb on the hose.
Then you can use a PVC slip/glue fit male threaded fitting on the PVC pipe.


Go to their catalog or www.[URL="http://www.forespar.com"]Forespar.com[/URL]

[peghall]

Originally Posted by rwidman

It would not be wise to glue hose onto pipe. The hose will need to be replaced at some point. Clamps are the best way to secure the hose to the pipe and still allow the hose to be replaced.

All sanitation system hoses, and/or any hoses connecting to a below-waterline thru-hull should be DOUBLE clamped, with screws on opposite sides of the hose.

[foufou]

in addition to the glue it solution which some do not like, there are no hub couplings of many sizes. these have a rubber sleeve with a stainless steel outer compression sleeve that has as many as 4 hose clamps that squeeze it all together. And these are available in different size at each end allowing more size combinations

[marlin driver]

Originally Posted by Pauls

Regards the OD of pipe, it does NOT depend on wall thickness. Pipe is specified by OD. Pipe wall thickness is specified by the schedule number, schedule 40 is the most common. Pipe ID varies with the wall thickness, but the OD remains constant.

Hose is just the opposite, it is specified by the ID, and the OD will vary with the wall thickness.

Pipe and hose are two different categories.

For the record, this isn't correct. Pipe is specified by ID. Hose is specified by ID. Tubing (metal tube, specifically) is specified by OD.

It makes sense because the relevant dimension for pipe and hose is the inside, since it's purpose is to move liquids or gas. Tubing is a structural material and the relevant dimension is OD and wall thickness.

[HopCar]

Both schedule 40 and 80 pipe have the same OD. 1-1/4 inch pipes are 1.66 OD.
Schedule 40 is 1.36 inches ID. Schedule 80 is 1.255 inches ID. It actually doesn't measure 1-1/4" anywhere.

This website will tell you both the ID and OD of pvc pipe.
Schedule 40 & 80 Pipe Dimensions

[marlin driver]

Originally Posted by HopCar

Both schedule 40 and 80 pipe have the same OD. 1-1/4 inch pipes are 1.66 OD.
Schedule 40 is 1.36 inches ID. Schedule 80 is 1.255 inches ID. It actually doesn't measure 1-1/4" anywhere.

This website will tell you both the ID and OD of pvc pipe.
Schedule 40 & 80 Pipe Dimensions

Good info and that also makes sense, so that the same fittings can join schedule 40 and schedule 80 of a given size, say 1 1/4". I would say 1.255 ID is pretty darn close to 1 1/4", but I guess that is a matter of opinion.

I guess my point is that 2" tubing and 2" hose is approximately 2" ID, while 2" tubing is approximately 2" OD.

Thanks for the info on how wall thickness affects ID of tubing.

[jr_spyder]

Here are exactly the the adapters you need:

https://www.plumbingsupply.com/pvc.html#barb

I redid all my sanitation hoses 4 years ago and used a combination of solid sched 40 PVC and Triton marine sanitation hose. Anywhere they joined I used these adapters. Both 1.5" for waste and 1" for vents. I like that they have both male and female types. All works great and has held up perfectly. I wouldn't try to piece together other random plumbing parts. Just get these.

This vendor was always quick to ship and got everything right.

Good luck,

JR

[HopCar]

Pipe sizes make no sense to me. The smaller sizes are quite a bit bigger ID than their nominal size, in the mid range they're pretty close to their nominal size, and from 14" and up the nominal size is actually their OD!

[ggray]

Hop, you are right, they don't make much sense, particularly the smaller sizes.

I understand that when the (nominal, remember) pipe sizes were established YEARS ago, someone over estimated the wall thickness needed for the smaller sizes, so when they realized that thinner would be sufficient, it resulted in a much larger ID than the nominal size.

But pipe sizes, though not close to exact, do refer to ID, not OD. Nevertheless, for a given pipe size regardless of schedule (as has been mentioned), all will all be the same.

[peghall]

I've never found anyone who can explain to me why a nominal 1.5" thread x 1.5" gray sched 80 tank fitting is actual 1.5" OD thread x 1.5" ID barb...resulting in a 1-5/8" OD hose barb that no one can get a 1.5" hose onto without heating the hose to point to tearing...or why this is only true of 1.5", no other sizes. Nor is it true of any other thread-barb fittings, only gray sched 80.

[ggray]

Peggie, I can't really follow your dimensions here, except for the last thing about the 1 5/8 barb. I have found some barbs to be bigger than what they should be, not sure why.

[peghall]

Peggie, I can't really follow your dimensions here...

I'll try to make them clearer: Fittings sizes should always be stated according to their OD... If they say it's 1.5 x 1.5, that SHOULD be the OD at both ends. Right?

So why is a nominal 1.5 x 1.5 thread-to barb (size clearly stamped into the fitting) actually 1.5" OD thread x 1.5" ID barb. That's only true of 1.5" gray sched 80 fittings, no other sizes or other materials. If you know why, you'll be first person I've found in 25 years who does.