Constant Pressure Spring Clamps

[skippydiesel]

You would think finding the following would be a no brainer. Think again - from weird sizing(SAAS) that does not relate to the OD of the hose, to just plain got no idea mate :

 

Constant Pressure Spring Clamps - you know the ones commonly found on low pressure fuel/air/vacuum lines (see below) to suit a silicone hose with a 9.5 mm OD

 

• 8mm ID resting (as in not being compressed/open or over a hose)
• Need a minimum of 12 ,would prefer about 24 units (spares for the shelf)

 

If you can recommend a reliable supplier (not SAAS) I would be very grateful

 

 

[ClintonB]

Wurth have screwless hose clamps with various sizes in 0.5mm increases as per picture, quality ones, tool is available for fitting and replacing.

ebay list budget ones everywhere in 100 packs for 20 bucks or so.

not sure of their airworthiness for lasting. 
cheers

clinton

[onetrack]

eBay always has this kind of stuff, and it's cheap, and is delivered to you as well.

 

https://www.ebay.com.au/itm/192582657284

 

 

Edited November 29, 2022 by onetrack
correct size ...

[skippydiesel]

Yes I ave seen the ebay stuff - even tried to get the ID from some suppliers - like pulling teeth.

 

Why is it so hard to get conformation of a specification (ID of resting band)? Even what I would call real stores (street address) seem to have issues with this. Check out SAAS their 5mm is really 10 mm, their 4 mm is about 6.5 mm and their 3 mm about 5mm - go figure!

[Blueadventures]

45 minutes ago, skippydiesel said:

Yes I ave seen the ebay stuff - even tried to get the ID from some suppliers - like pulling teeth.

 

Why is it so hard to get conformation of a specification (ID of resting band)? Even what I would call real stores (street address) seem to have issues with this. Check out SAAS their 5mm is really 10 mm, their 4 mm is about 6.5 mm and their 3 mm about 5mm - go figure!

You need to buy an assorted pack.  At worst will be a waste of money.  On plus side you will have sizes either size for other needs.

[spenaroo]

8mm is equal to 5/16 its the most common size fuel line used on motorcycles 
should be able to walk into a Bursons to get them. 

though these days everyone has swapped to the crimp style
 

[skippydiesel]

7 hours ago, spenaroo said:

8mm is equal to 5/16 its the most common size fuel line used on motorcycles 
should be able to walk into a Bursons to get them. 

though these days everyone has swapped to the crimp style
 

I don't really work in/recognise the devils measurements that should have been scrapped a trillion years ago.

 

My local Bursons don't have them (offered screw type).

 

Crimps are for too sophisticated and are not reusable or serviceable in the" field". Nor do they give constant pressure, over time, like the spring type. 

[Blueadventures]

26 minutes ago, skippydiesel said:

I don't really work in/recognise the devils measurements that should have been scrapped a trillion years ago.

 

My local Bursons don't have them (offered screw type).

 

Crimps are for too sophisticated and are not reusable or serviceable in the" field". Nor do they give constant pressure, over time, like the spring type. 

I feel sorry for you not being an adaptable all rounder:)

[kgwilson]

Norma Cobra hose clamps are the best IMO. They are made specifically for each size hose from 8mm to 38mm and are very low profile so don't catch on anything, German made SS and there are special pliers for clamping and unclamping though you can use ordinary pliers. I have them on all fuel fittings in my aircraft.

 

[skippydiesel]

27 minutes ago, kgwilson said:

Norma Cobra hose clamps are the best IMO. They are made specifically for each size hose from 8mm to 38mm and are very low profile so don't catch on anything, German made SS and there are special pliers for clamping and unclamping though you can use ordinary pliers. I have them on all fuel fittings in my aircraft.

Hi Kgwilson - I have absolutely no doubt that they "are the best" BUT as usual I have  a divergent opinion COST/EFFECTIVNESS - all my clamps (for whatever application ) are reusable, can be applied (at home or "in the field") using existing tools, from most pilots basic (or advanced) tool kit, with just a little skill  & attention to detail (know how).

 

I go to considerable trouble to find the right clamp for each "job", usually purchase by the box, as this is most often the best price /unit and leaves me with a few spares (just in case).

 

The small spring band hose clamps , suitable for low pressure fuel/air/oil, that I was looking for & now found ( AASpray www.airless.com.au) cost me $23.55 /24 delivered. I will only use 12 (on my pneumatic pitot/static/AofA system), the remaining are spares in the unlikely event that I will need to replace 1 or 2, way way "down the track". The pneumatic system, referred to, will only experience pressures at or slightly above, ambient. The push on fittings are fairly secure & seal in their own right, so the spring clamps just provide that little bit of reassuring extra security/ 360 sealing pressure.

[Area-51]

Norma Clamps

 

Australian distributor, located on Goldcoast..  Uniclamp

 

Call Ron 1300 027 886.

 

Buy a complete kit; pliers included.

 

Buy additional packs of each size marked with a dot in the pics if undertaking a complete Rotax hose change.

 

Request CLR-92235 23.0mm-24.5mm clamps also.

[skippydiesel]

Rotax supply their engines with Constant Tension Spring Clamps, as per most if not all newer cars.               

 

They are reusable, can be removed /replaced in the field, with the appropriate applicators (regular pliers will do the job with difficulty).

 

Give 360 degree constant clamping pressure, CONSTANT in that as long as the spring tension remains it will not pinch or loosed and can not be over tightened (like so many clamps I have seen).

 

I do understand that their is reassurance/satisfaction in tightening all the other styles of clamp but if Rotax and all those car manufacturers find the spring clamp to be satisfactory, I think this speaks volumes.

 

As with all clamps, select the most appropriate size for the OD of the hose being clamped.

 

https://www.norma.net.au/brands/norma/normaclamp-torro-ct-constant-tension-clamp-kit-100-pieces-?catid=3055

 

https://www.autopartswholesalers.com.au/products/hose-clamps/norma/normaclamp-fbs-constant-tension-springband-clamps