LP hose inner diameter

undrh2o · 8th May 2007, 16:39

I'm putting together an order for my IDA conversion parts and I'm looking for the size of barb to 1/8 npt fittings I need for low pressure hoses. Does anybody know the inner diameter of low pressure hoses?

marekm · 8th May 2007, 17:17

Hi undrh2o,

This 7ft LP hose here Scubaroo Diving Supply - OxyCheq Australia has an internal diameter of 7.9mm

The 1/4" barb on the the McMaster Carr fitting had an outside diameter of 6.8mm. Thus your looking for a LP hose with an internal diameter of 6.8 or smaller.

The barb on the AP valves screw on 3/8"UNF LP hose fittings has a 8.6mm outer diameter, so it works well with this hose.

Cheers.
-Marek

undrh2o · 8th May 2007, 19:01

I think the reason that the McMaster parts you had didn't fit (44555K131) was that they are for Poly tube fittings not necessarily rubber hose.

Dave Sutton has mentioned in other posts that the 1/8 NPT fittings come in bags of 10 which corresponds to part numbers mentioned in an old thread of 5346K13 and 5346K41 which both are for a hose inner diameter of 1/4".

I'll check my hoses when I get home and see which will work best unless someone can confirm that these are the ones to use.

undrh2o · 9th May 2007, 00:19

Answering my own query

Marekm - not sure why your hose differs from mine but I just cut off the end of an old LP reg hose (octo length) and found the inner diameter to be .22" or 5.8mm on my digital calipers which makes those part numbers above correct for me at least.

Also the outer hose diameter is 1/2" or approx 13mm so for for the ear clamps should anyone else need them I think it's McMaster Carr part number 5435K13 for the SS single pinch or possibly the 5435k14 for slightly larger OD hose.

**Dave Sutton** · 9th May 2007, 04:27

1/4 inch is the ID of standard hose.

K13 crimps work best. Use soap to help them slide into place for the crimp.

1/4 inch "Push On" hose is the stuff to buy if you need hose.

Best,

Dave

marekm · 9th May 2007, 05:28

Quote: (Originally Posted by undrh2o)

not sure why your hose differs from mine

Probably because each scuba LP hose manufacturer had their own idea of what internal and external diameter is considered 'standard'.

-Marek

undrh2o · 9th May 2007, 11:51

Quote: (Originally Posted by Dave Sutton)

1/4 inch is the ID of standard hose.

K13 crimps work best. Use soap to help them slide into place for the crimp.

1/4 inch "Push On" hose is the stuff to buy if you need hose.

Best,

Dave

Does That mean I should be using the push on hose fittings listed on catalog page 254 - 255 instead of the part numbers above?

Is Buna-N O2 compatible?

Thanks

**Dave Sutton** · 9th May 2007, 13:30

Quote: (Originally Posted by undrh2o)

Does That mean I should be using the push on hose fittings listed on catalog page 254 - 255 instead of the part numbers above?

Is Buna-N O2 compatible?

Thanks

Uhh...... I *have* used the push-on fittings, and I liked them. Removes the need to crimp and makes a clean installation. I still use barbs though more than push on. Either can be used in the push-on hose. Basically, I ended up crimping the push-on hose fittings anyhow. Braces and Belt, I guess. They work fine without the crimp, but...... dunno.

1/4 is a VERY common ID for diving hose. It's a very rare exception that is different. I'd say 99% to 1% is a good ratio of 1/4 to "other".

Dave

undrh2o · 16th May 2007, 03:12

Quote: (Originally Posted by Dave Sutton)

1/4 is a VERY common ID for diving hose. It's a very rare exception that is different. I'd say 99% to 1% is a good ratio of 1/4 to "other".
Dave

I found this interesting - I just read that the new Dive Rite hurricane regs use a LP hose with a larger ID "for better air flow" not sure but seems like marketing BS to me

**Dave Sutton** · 16th May 2007, 13:33

Quote: (Originally Posted by undrh2o)

I found this interesting - I just read that the new Dive Rite hurricane regs use a LP hose with a larger ID "for better air flow" not sure but seems like marketing BS to me

It is. This has been trotted out by makers for years. Even Dacor tried to generate interest in it.... and failed.

What works, works. 1/4 ID works.

Dave

8th May 2007, 16:39	#1 (permalink)
undrh2o Chris Miller Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Inspiration Classic Other CCR Dolphin Home Build Join Date: Apr 2006 Location: Ottawa, Canada Posts: 206	LP hose inner diameter I'm putting together an order for my IDA conversion parts and I'm looking for the size of barb to 1/8 npt fittings I need for low pressure hoses. Does anybody know the inner diameter of low pressure hoses?
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8th May 2007, 17:17	#2 (permalink)
marekm Banned Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Oct 2006 Location: Brisbane, Australia Posts: 196	Re: LP hose inner diameter Hi undrh2o, This 7ft LP hose here Scubaroo Diving Supply - OxyCheq Australia has an internal diameter of 7.9mm The 1/4" barb on the the McMaster Carr fitting had an outside diameter of 6.8mm. Thus your looking for a LP hose with an internal diameter of 6.8 or smaller. The barb on the AP valves screw on 3/8"UNF LP hose fittings has a 8.6mm outer diameter, so it works well with this hose. Cheers. -Marek Last edited by marekm : 8th May 2007 at 17:23.
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8th May 2007, 19:01	#3 (permalink)
undrh2o Chris Miller Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Inspiration Classic Other CCR Dolphin Home Build Join Date: Apr 2006 Location: Ottawa, Canada Posts: 206	Re: LP hose inner diameter I think the reason that the McMaster parts you had didn't fit (44555K131) was that they are for Poly tube fittings not necessarily rubber hose. Dave Sutton has mentioned in other posts that the 1/8 NPT fittings come in bags of 10 which corresponds to part numbers mentioned in an old thread of 5346K13 and 5346K41 which both are for a hose inner diameter of 1/4". I'll check my hoses when I get home and see which will work best unless someone can confirm that these are the ones to use.
(Offline)

9th May 2007, 00:19	#4 (permalink)
undrh2o Chris Miller Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Inspiration Classic Other CCR Dolphin Home Build Join Date: Apr 2006 Location: Ottawa, Canada Posts: 206	Re: LP hose inner diameter Answering my own query Marekm - not sure why your hose differs from mine but I just cut off the end of an old LP reg hose (octo length) and found the inner diameter to be .22" or 5.8mm on my digital calipers which makes those part numbers above correct for me at least. Also the outer hose diameter is 1/2" or approx 13mm so for for the ear clamps should anyone else need them I think it's McMaster Carr part number 5435K13 for the SS single pinch or possibly the 5435k14 for slightly larger OD hose.
(Offline)

9th May 2007, 04:27	#5 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: LP hose inner diameter 1/4 inch is the ID of standard hose. K13 crimps work best. Use soap to help them slide into place for the crimp. 1/4 inch "Push On" hose is the stuff to buy if you need hose. Best, Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
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9th May 2007, 05:28	#6 (permalink)
marekm Banned Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Oct 2006 Location: Brisbane, Australia Posts: 196	Re: LP hose inner diameter Quote: (Originally Posted by undrh2o) not sure why your hose differs from mine Probably because each scuba LP hose manufacturer had their own idea of what internal and external diameter is considered 'standard'. -Marek
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9th May 2007, 11:51	#7 (permalink)
undrh2o Chris Miller Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Inspiration Classic Other CCR Dolphin Home Build Join Date: Apr 2006 Location: Ottawa, Canada Posts: 206	Re: LP hose inner diameter Quote: (Originally Posted by Dave Sutton) 1/4 inch is the ID of standard hose. K13 crimps work best. Use soap to help them slide into place for the crimp. 1/4 inch "Push On" hose is the stuff to buy if you need hose. Best, Dave Does That mean I should be using the push on hose fittings listed on catalog page 254 - 255 instead of the part numbers above? Is Buna-N O2 compatible? Thanks
(Offline)

9th May 2007, 13:30	#8 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: LP hose inner diameter Quote: (Originally Posted by undrh2o) Does That mean I should be using the push on hose fittings listed on catalog page 254 - 255 instead of the part numbers above? Is Buna-N O2 compatible? Thanks Uhh...... I have used the push-on fittings, and I liked them. Removes the need to crimp and makes a clean installation. I still use barbs though more than push on. Either can be used in the push-on hose. Basically, I ended up crimping the push-on hose fittings anyhow. Braces and Belt, I guess. They work fine without the crimp, but...... dunno. 1/4 is a VERY common ID for diving hose. It's a very rare exception that is different. I'd say 99% to 1% is a good ratio of 1/4 to "other". Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
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16th May 2007, 03:12	#9 (permalink)
undrh2o Chris Miller Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Inspiration Classic Other CCR Dolphin Home Build Join Date: Apr 2006 Location: Ottawa, Canada Posts: 206	Re: LP hose inner diameter Quote: (Originally Posted by Dave Sutton) 1/4 is a VERY common ID for diving hose. It's a very rare exception that is different. I'd say 99% to 1% is a good ratio of 1/4 to "other". Dave I found this interesting - I just read that the new Dive Rite hurricane regs use a LP hose with a larger ID "for better air flow" not sure but seems like marketing BS to me
(Offline)

16th May 2007, 13:33	#10 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: LP hose inner diameter Quote: (Originally Posted by undrh2o) I found this interesting - I just read that the new Dive Rite hurricane regs use a LP hose with a larger ID "for better air flow" not sure but seems like marketing BS to me It is. This has been trotted out by makers for years. Even Dacor tried to generate interest in it.... and failed. What works, works. 1/4 ID works. Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
(Offline)

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