Double jubilee clips and why?

whiteoaks7

whiteoaks7

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Joined
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570
Location
South Wales, UK
www.seasolutions.co.uk
I've spent a memorable weekend fitting my new holding tank. My only real problem was that the Whale 3 port valve didn't really present enough stub length to get two jubilee clips on (why not Whale???) Since this is connected to the ocean I felt somewhat nervous about just having the one.

This made me question why we fit double clips anyway. As far as I can see there are two reasons (a) the flatish porion of the clip where the screw is may present a leakage path and this can be joggled if there are two clips to improve the seal, (b) if one clip fails there is another already in place to take over. Realistically, the latter reason never works (a well known reliability issue called hidden failure comes into play - one fails but you don;t know it therefore you rely on the one that's left therefore you only needed the one in the first place). Maybe it's better to fit one and worry about it and therefore check it regularly than fit two and have this warm cosy feeling that everything is right when if fact catastrophy can be just a drip away.

Or have I missed the real reason? What do the team think?
 
I have also wondered about this. I concluded that there are at least two reasons. Firstly the leakage path one but secondly and probably more importantly is the mechanical one of increasing the area that is compressed under the clips and so reducing the chance of the hose being displaced by pressure. Having said that I have a couple of connections close to the water line where there is only one clip because there simply isn't space to get a second one on.
Morgan
 
What I find annoying on a lot of fittings is that the hose spigot is always too short, and unless one is buying a hose spigot for a specific job or fitting there is never enough ribbs on the spigot which plays a huge part in actually holding the hose on.
These ribs are like barbs on fishing hooks and wont allow slippage of the hose once it is reasonably tight.
"So Please, More Ribbs on Bigger Spigots"
 
I only double clamp connections to seacocks below the waterline and whatever they are connected to inboard if that device is also below the waterline. My three way holding tank valve would be above the waterline and so not double clamped.
The biggest problem I have with hose clamps is the sharp ends - a skirmish around the bilge leaves your hands looking like you've had a fight with a porcupine. My last boat had little plastic caps on the ends of all hoseclamps - bliss!
 
It's a myth perpetrated by hose clip manufacturers and yachting journalists. There are billions of cars on the road throughout the world, the vast majority of which have cooling systems operating at a pressure of up to 12 psi. All have a number of single hose clips that successfully retain near boiling coolant at this pressure.

In contrast, very few yacht hose attachments operate at more than a couple of feet of water pressure, less than 1 psi, without vibration and at very modest temperatures. Provided that the hose is not exceptionally stiff, a single hose clip is perfectly adequate IMHO.
 
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There are billions of cars on the road throughout the world, the vast majority of which have cooling systems operating at a pressure of up to 12 psi. All have a number of single hose clips that successfully retain near boiling coolant at this pressure.


[/ QUOTE ]
True, but cars do not often sink when their hoses blow off! And their hoses are not often in a salt-laden 100% humidity corrosive environment, hidden away behind smart panels and sometimes left un-inspected for years.
I have a vivid memory of taking over one old-ish yacht for a delivery, going round checking all through-hulls, finding on with a very rusty hoseclip and giving it a prod with a screwdriver: it snapped and water began to dribble in!
 
If the hoseclip fails on your car you stop ... or the engine does ... if the clip goes on your boat you have to turn off the seacock .. otherwise you will (eventually) sink ... for the sake of the cost of a second clip - I'd double clip wherever possible....

Just off to tighten my belt ... braces are still working fine though! /forums/images/graemlins/tongue.gif
 
But that reinforces my point - if you'd had two clips they both would have been the same age and condition - they both would have broken off.

The other implication is that the ship fitter used a mild steel clip, not a stainless one.

Believe me, I understand the feeling that two are better than one, but in reliability terms, I think, two offers no advantage (I will however fit two because I do not trust the insurance companies of the world).
 
Ordinary jubilee clips are made of a strip with slots cut in it, and can fail merely through slipping. Better clips have a raised corrugated 'thread' which is less prone to failure, and the best quality are drawn together with a bolt through two bosses. You get what you pay for.
 
But when did you last hear of a car blowing off a hose that still had its clip attached? I have yet to hear of one. Rusty hoseclips used to be a problem but all-stainless ones are far more reliable. Even the ones with a stainless strap and ferrous screw seem to mostly fail safe - the screw rusts solid and you can't undo it but it holds for a long time in that condition.
 
If your vessel is in survey the regulations will often state that two clips have to be used everywhere. Some items don't have room for two clips and in my engine room I have hoses with two clips, one of them is there just for decoration. The surveyer is not going to be any wiser.
 
I'm with Vyv on this one. The automotive industry have turned out several orders of magnitude more vehicles than the marine industry and if 0.0001% of those failed any major manufacturer would have a BIG problem on his hands. The truth is, it simply doesn't happen that often (or anything like it)!

Cars work (these days) at rather more than 12 psi (getting on for double that!) and they are subject to extremes of temperature every time they fire up that boats don't get anywhere near. Boats might work in a salty environment but the hose clips tend not to - at least not as salty as the environment my car's radiator hose clips work in over the winter! Even some car fuel tank hoses only use one clip!

I also don't buy the leakage theory because (again going back to cars) they seem to be able to withstand boiling water & antifreeze at much higher pressures than seacocks without weeping.

Then finally, there's the point already raised about how few fittings are actually wide enough to take two clips. Having had the same experience with a surveyor wanting double clips, I splashed out on some and fitted them (unfortunately on the wrong side of the spout in some cases) but it seemed to make him happy and I took the view that at least I had a load of spare clips ready to hand if I should have one fail!
 
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If your vessel is in survey the regulations will often state that two clips have to be used everywhere. Some items don't have room for two clips and in my engine room I have hoses with two clips, one of them is there just for decoration. The surveyer is not going to be any wiser.

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Regulation ???? That word again ....

As far as I know the requirement for two clips is a reccomended "safe-practice" and not a regulation.

I would also suggest that it is prudent to comply if only to stop an efficious smart-arse Loss adjuster amending your claim in event of incident - and it doesn't even need to be due to the clips !!
 
Just received this note from L Robinson & Co

"Dear Sirs


The name “Jubilee” is being used on your site generically when it is in fact the registered trade mark of L Robinson & Company (Gillingham) Limited and as such we have the exclusive right to use that mark in the context of hose clips. It is therefore unlawful for any unauthorised party to use JUBILEE when referring to hose clips unless such clips are of our manufacture.

There are many manufacturers of hose clips around the world and many different types, combinations of material and different designs of hose clips so the potential problems that can be experienced if the wrong type of clips are used or are incorrectly fitted are without number.

If you combine this with different spigot and connectors and umpteen different types of hose (not necessarily being used on the correct application), then surely the solution is common sense and experience. Use a clip that has a well known brand name and therefore good quality manufacturing, to an established Standard (for instance Jubilee all stainless steel 304 made to BS 5315:1991, Kitemarked and Lloyd’s Type Approved and by a company with ISO 9002 approval). Also ensure you are using the correct type of clips for the application, ie Standard Range, High Torque, Superclamp etcetera – details can be found on our website www.jubileeclips.co.uk <http://www.jubileeclips.co.uk/> or even contact us.

With regard to fitting two hose clips - for peace of mind, and a relatively small cost, there is no harm in being absolutely sure and fitting two clips.

To sum up:-

Jubilee should not be used as a common name for hose clips – if it is Jubilee it says so on the housing.
Not all other manufacturers produce stainless steel clips that are completely stainless steel, they may be a combination of mild steel and stainless steel. Jubilee is 100% stainless steel.
If a competitor says they produce to BS 5315 it does not necessarily mean their product is Kitemark approved, Jubilee is produced to BS 5315:1991 and has Kitemark approval therefore the quality is checked by the British Standards. In fact Jubilee clips exceed British Standards requirements. Plus our stainless steel range is Lloyd’s Type Approved.

Perhaps you would be kind enough to include this article on your ‘World Forums’.

Regards
Chris Bunting"

Happy to point out this correction.
 
These people just can't cope with success, can they?
After spending years telling us how wonderful jubilee clips are (like plasticene, biros, snopake, rawlplugs, snopake, hoovers, pop rivits etc) they get us all using the words everyday. An advertising success story. Then they get all uppitty because the message has got across too well, and the word has passed into the language.
What did they want then - to remain an obscure little unknown backstreet company in Gillingham, producing some clips no one ever wanted or had heard of?
Would they be happier if I remembered the names of all their competitors, and started bandying them about instead?
 
I don't agree with the emerging consensus here that two hose clips are unneccessary.

The underlying justification for that seems to be that in all likelihood both clips will be of the same age and both fail at the same time.

While according to sod's law that is not impossible, in practice it is extremely unlikely.

Furthermore, all hose clips should be inspected annually and that ought to reduce the possibility of any hose clip reaching failure state. And if one does, between inspections, then as I said before the likelihood of the second one doing so is small.

When I took on my boat nearly twenty years ago there were several failing hose clips in the early years; since I replaced all of them with good quality clips and inspected each year there has been no incidence of failure.

Seems like an argument for just one clip? Almost, but what if I skip one clip, or miss the early signs of failure? And, again, I have once or twice 'tightened' a hose clip only to find on closer inspection that it was not really tight, just friction bound.

All in all I feel a lot happier with two clips.
 
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for instance Jubilee all stainless steel 304 made to BS 5315:1991, Kitemarked and Lloyd’s Type Approved and by a company with ISO 9002 approval)

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Pls remind me NOT to use jubilee clips as they are only 304 stainless and not 316.

We have a local supplier of a german brand (can't remember name) from whom I buy only "worm drive hose clips" in 316 stainless

Found details here of a much better worm drive clip than Jubilee IMHO of cause

use my email address in my bio as login
 
I am reminded of the airline pilot who retired after many years flying Boeing 707 and 747 aircraft.

He was asked why he always flew 4 engined aircraft.

He thought for a moment and answered in a slow Texan drawl

"Because Boeing don't make one with five"
 
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