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air travel with strobes (air pressure effects)


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#1 bremner

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Posted 05 February 2018 - 07:15 PM

I'm soon to set off on my first plan trip with underwater gear. I plan to carry on a smallish rig with a housed EM5-II and a Sea&Sea YS01 strobe. I've heard people talk about taking the o-rings out of housings so that they don't vacuum seal because of lower pressure in airplane cabins. Is that a worry for strobes as well? I guess the air cavity in the YS-01 is much smaller. Any words of wisdom?



#2 echo2600

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Posted 05 February 2018 - 07:32 PM

My YS-01s have been on many flights, as both carry-on and checked baggage, with the battery compartments closed (o-rings in place) without issue. Unless someone has had considerably different experiences, I wouldn't fret it much. Of course, ymmv..

 

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#3 okuma

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Posted 05 February 2018 - 08:09 PM

Underwater equipment is designed with O rings/seals for a higher ambient(outside) pressure than internal. 

Air travel, even in pressurized planes results in a lower  than ground level pressure.

Consequently, you should always remove user accessed O rings.

Worst case condition you could pop a non accessable ring out of it's seat.


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#4 echo2600

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Posted 05 February 2018 - 09:52 PM

That begs the question... if the battery compartment is isolated from the electronics, which most are these days, what good does removing battery cap o-rings do for safeguarding the rest of the electronics? If the seal between the battery and the electronics compartment is going to be truly effective it has to be as robust as the rest of the seals in the strobe. Meaning even with the battery o-rings removed all of the rest of the seals are likely just as vulnerable... Just my opinion

The vacuum argument holds water a bit better in that some battery compartments do have pressure relief mechanisms (Inon Z240s come to mind)... though Id be surprised if the 0.15-0.20 bar pressure differential in an aircraft cabin would be enough to activate them. That is just my speculation, so if anyone has data to show otherwise, Id gladly be proven wrong.

#5 TimG

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Posted 05 February 2018 - 10:50 PM

Interesting!

It’s not scientific, but I’ve travelled with strobes dozens of times by air and have never thought to remove battery cover o-rings. Never had the slightest problem.

I definitely remove the housing o-ring though. If a port is also fitted with its o-ring, removing the port or housing back if the housing o-ring is fitted can be a nightmare after flying.

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#6 divengolf

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Posted 06 February 2018 - 06:41 PM

Agree with TimG. I also travel with strobes checked and as carry on. Always have batteries installed with the switches jammed with a shim so they will not accidently turn on. So there's not much of an air space to be concerned about. Even without the batteries, I'd not be concerned.

 

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#7 echo2600

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Posted 06 February 2018 - 07:09 PM

Let me preface this with I'm really just thinking out loud (so to speak): In regards to the housing o-ring, what if you have a vacuum port installed and left the cap off of it? Do you think that would allow the housing to equalize during the flight? If so, equalizing it again back on the ground wouldn't be an issue. Considering the much larger surface area inside a housing, the force exerted by the pressure differential could end up being fairly substantial - which might explain a port mount bayonet failure that I experienced last year after a several leg journey... Doing some quick math, 0.2 bar pressure exerted over the cross-sectional are of a N85 port equates to just shy of 58 Newtons force, or the equivalent of hanging a 6 kg weight off the end of the port... D'oh!



#8 TimG

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Posted 06 February 2018 - 10:29 PM

Let me preface this with I'm really just thinking out loud (so to speak): In regards to the housing o-ring, what if you have a vacuum port installed and left the cap off of it? Do you think that would allow the housing to equalize during the flight? If so, equalizing it again back on the ground wouldn't be an issue. Considering the much larger surface area inside a housing, the force exerted by the pressure differential could end up being fairly substantial - which might explain a port mount bayonet failure that I experienced last year after a several leg journey... Doing some quick math, 0.2 bar pressure exerted over the cross-sectional are of a N85 port equates to just shy of 58 Newtons force, or the equivalent of hanging a 6 kg weight off the end of the port... D'oh!

 

 

Depends I think on the design of the vacuum valve. As an example, leaving the top off the Vivid would make no difference to the pressurisation.  But by shifting the little red seal with your finger (as it's designed to do) it would open the valve and release - or equalise - pressure in the housing.

 

It'd be a safety mechanism (I think!) if you had closed the housing up with an o-ring and port installed and then flown.


Tim
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Nikon D800 and D500, Nikkors 105mm and 16-35mm, Sigma 15mmFE, Tokina 10-17,  Subal housing

http://www.timsimages.uk
Latest images: http://www.shutterst...lery_id=1940957


#9 Walt Stearns

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Posted 07 February 2018 - 10:44 AM

I all the years (36+) of air travel, with the highest amount during the 1990’s where I was traveling as often as twice amount for magazines, I never gave a second thought high altitude pressure changes might have on my strobes in the belly of a passenger jet. And I have traveled with a few, Subsea, Oceanic’s, Ikelite’s, Sea&Sea’s, MCD’s, etc. and never have had appear to a affected buy the journey. As for batteries, especially my Seas & Sea’s, my only trouble there was not have airport security on occasion not understanding what they were, to more recently convincing them that they are NiMh and not Lithium.



#10 ChrisRoss

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Posted 17 February 2018 - 09:43 PM

It really is not a problem flying with strobes or housings with O-rings in place.  The O-rings will resist the pressure change with no problem   My Nauitcam housings both arrived with the main o-ring in place as did the two INON Z-240s, both arrived in Australia via air freight.  The pressure change form sea level to 2400m (planes are pressurized to 2400m or 8000 ft) is 0.25 bar.  Going down to 10m gives you approx. 1 bar external pressure for comparison.

 

It is more challenging to design for external pressure due to rigidity requirements to prevent buckling collapse, so running the housing at 0.25 bar positive is trivial - not a problem at all.  The main reason to remove O-rings is to prevent them flattening or taking a set from prolonged compression with the door in place. 

 

On a sidenote you may run into trouble if you open your housing at altitude, close it and take it to sea level.  Unless you had a vacuum valve to vent it you could have trouble opening it at sea level due to external pressure, just like a Vacuum system.  In any case I imagine mostly you transport the housing and port separate so the body and port cap would prevent any pressuring up.