Deeper that how much the hansets need to be fill with oil?

mikel-deko · September 19th, 2012, 05:11 PM

Hello

We are planning some deep dives and woudl like to know deeper that how much the hansets need to be fill with oil.
We are diving a Inspi Classic Hammerhead Rec C and a Meg.
I've read somewhere that the baterry box in the meg also need to be filled with oil.
And also what oil will be the best to do it?

Thanks
Mikel

divetheworld · September 19th, 2012, 06:55 PM

Oil expands and contracts with temperature changes. That pressure will have hydraulic effects on the casing so you may cause more damage than you are trying to prevent. Some oil filled devices also have a small bladder inside to take up these changes but have to be carefully quantified depending on the volume and coefficients of expansion.
It's not that simple. Look into ways of strengthening the assembly and minimising gas volume in the housings first if you can.

lizardland · September 19th, 2012, 08:04 PM

IIRC there is info on how to fill display housings with oil in the Mk15 manual if you can find a copy PDF.

It may be a time to keep it simple. I remember sitting down one day and working out the crush depth of olde worlde homebuilder's lexan tube housings. I can't remember the depth but it was in four figures (metres). I guess with anything the weak point is the gland.

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Peter L · September 19th, 2012, 08:10 PM

Quote: (Originally Posted by lizardland)

IIRC there is info on how to fill display housings with oil in the Mk15 manual if you can find a copy PDF.

It may be a time to keep it simple. I remember sitting down one day and working out the crush depth of olde worlde homebuilder's lexan tube housings. I can't remember the depth but it was in four figures (metres). I guess with anything the weak point is the gland.

Sent from my GT-I9100 using Tapatalk

In 4 figures you have bigger issues with synovial joints crush, can you imagine what it feels like for your hips, knees and shoulders to lock down because the joints are no longer able to articulate....

Mike Ferguson · September 19th, 2012, 10:25 PM

oil filling is standard practice on subsea electronics in the offshore industry. normally a dialectric oil (transformer oil) is used but at a pinch tellus 22 or glycerine can be used. To avoid issues with thermal volume changes and oil compressibility with pressure, standard practice is to tap the housing and fit a small external oil filled bladder for thermal expansion/compression. I've put fairly thin walled casings to well over a thousand metres doing this. BUT, and theres always a but, you need to ensure oil compatibility with the components and ensure that there are no sealed components in there at 1 ATM that will go pop when the pressure in the case increases.
Alternatively you could pressurise the inside of the housing to reduce the pressure differential across the casing at depth. i.e. put in 10 barg at the surface (if your housing will take it) and you've just increased your depth rating by 100m.

However as John said, sometimes it's easier and safer to just open it up and pot it to get rid of the air spaces.

packeteer · September 24th, 2012, 09:00 AM

define deep?

i know guys with classics that regularly do 130m dives

mikel-deko · September 24th, 2012, 11:29 AM

Quote: (Originally Posted by packeteer)

define deep?

i know guys with classics that regularly do 130m dives

Hi, I dive a classic with a Hammerhead Electronick.

My dive budy a Standar MEG.

We are talking about 130/160 mtrs in 7.5ºC.

Thanks for all the answers.

Mikel

lizardland · September 24th, 2012, 12:00 PM

Quote: (Originally Posted by mikel-deko)

Hi, I dive a classic with a Hammerhead Electronick.

My dive budy a Standar MEG.

We are talking about 130/160 mtrs in 7.5***186;C.

Thanks for all the answers.

Mikel

IIRC Hammerhead handsets are rated to 600ft/180m. Might be worth checking with KJ.

Sent from my GT-I9100 using Tapatalk

mikel-deko · September 24th, 2012, 06:07 PM

Quote: (Originally Posted by lizardland)

IIRC Hammerhead handsets are rated to 600ft/180m. Might be worth checking with KJ.

Sent from my GT-I9100 using Tapatalk

Thanks, i will check it.

September 19th, 2012, 05:11 PM	#1 (permalink)
mikel-deko New Member Join Date: Mar 2012 Location: Basque Country Posts: 41 Thanks: 5 Thanked 6 Times in 4 Posts	Deeper that how much the hansets need to be fill with oil? Hello We are planning some deep dives and woudl like to know deeper that how much the hansets need to be fill with oil. We are diving a Inspi Classic Hammerhead Rec C and a Meg. I've read somewhere that the baterry box in the meg also need to be filled with oil. And also what oil will be the best to do it? Thanks Mikel
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September 19th, 2012, 06:55 PM	#2 (permalink)
divetheworld New Member Join Date: Mar 2012 Location: UK Posts: 184 Thanks: 13 Thanked 7 Times in 2 Posts	Oil expands and contracts with temperature changes. That pressure will have hydraulic effects on the casing so you may cause more damage than you are trying to prevent. Some oil filled devices also have a small bladder inside to take up these changes but have to be carefully quantified depending on the volume and coefficients of expansion. It's not that simple. Look into ways of strengthening the assembly and minimising gas volume in the housings first if you can. __________________ Copying skips understanding. Understanding is how you grow. You have to understand why something works or why something is how it is. When you copy it, you miss that. www.narkedat90.com Workplace and Machinery Safety Consultancy - www.puwer.co.uk www.ce-eu.com
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September 19th, 2012, 08:04 PM	#3 (permalink)
lizardland New Member Join Date: Apr 2012 Location: North Posts: 273 Thanks: 82 Thanked 106 Times in 36 Posts	IIRC there is info on how to fill display housings with oil in the Mk15 manual if you can find a copy PDF. It may be a time to keep it simple. I remember sitting down one day and working out the crush depth of olde worlde homebuilder's lexan tube housings. I can't remember the depth but it was in four figures (metres). I guess with anything the weak point is the gland. Sent from my GT-I9100 using Tapatalk __________________ Jesus don't want me for a sunbeam
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September 19th, 2012, 08:10 PM	#4 (permalink)
Peter L New Member Join Date: Apr 2012 Location: London Posts: 299 Thanks: 12 Thanked 19 Times in 13 Posts	Quote: (Originally Posted by lizardland) IIRC there is info on how to fill display housings with oil in the Mk15 manual if you can find a copy PDF. It may be a time to keep it simple. I remember sitting down one day and working out the crush depth of olde worlde homebuilder's lexan tube housings. I can't remember the depth but it was in four figures (metres). I guess with anything the weak point is the gland. Sent from my GT-I9100 using Tapatalk In 4 figures you have bigger issues with synovial joints crush, can you imagine what it feels like for your hips, knees and shoulders to lock down because the joints are no longer able to articulate....
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September 19th, 2012, 10:25 PM	#5 (permalink)
Mike Ferguson WTF is that? Join Date: Mar 2012 Location: Aberdeenshire Posts: 250 Thanks: 11 Thanked 116 Times in 44 Posts	oil filling is standard practice on subsea electronics in the offshore industry. normally a dialectric oil (transformer oil) is used but at a pinch tellus 22 or glycerine can be used. To avoid issues with thermal volume changes and oil compressibility with pressure, standard practice is to tap the housing and fit a small external oil filled bladder for thermal expansion/compression. I've put fairly thin walled casings to well over a thousand metres doing this. BUT, and theres always a but, you need to ensure oil compatibility with the components and ensure that there are no sealed components in there at 1 ATM that will go pop when the pressure in the case increases. Alternatively you could pressurise the inside of the housing to reduce the pressure differential across the casing at depth. i.e. put in 10 barg at the surface (if your housing will take it) and you've just increased your depth rating by 100m. However as John said, sometimes it's easier and safer to just open it up and pot it to get rid of the air spaces.
(Offline)

September 24th, 2012, 09:00 AM	#6 (permalink)
packeteer Big Member Join Date: Mar 2012 Location: Sydney, AU Posts: 68 Thanks: 1 Thanked 2 Times in 1 Post	define deep? i know guys with classics that regularly do 130m dives
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September 24th, 2012, 11:29 AM	#7 (permalink)
mikel-deko New Member Join Date: Mar 2012 Location: Basque Country Posts: 41 Thanks: 5 Thanked 6 Times in 4 Posts	Quote: (Originally Posted by packeteer) define deep? i know guys with classics that regularly do 130m dives Hi, I dive a classic with a Hammerhead Electronick. My dive budy a Standar MEG. We are talking about 130/160 mtrs in 7.5ºC. Thanks for all the answers. Mikel
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September 24th, 2012, 12:00 PM	#8 (permalink)
lizardland New Member Join Date: Apr 2012 Location: North Posts: 273 Thanks: 82 Thanked 106 Times in 36 Posts	Quote: (Originally Posted by mikel-deko) Hi, I dive a classic with a Hammerhead Electronick. My dive budy a Standar MEG. We are talking about 130/160 mtrs in 7.5***186;C. Thanks for all the answers. Mikel IIRC Hammerhead handsets are rated to 600ft/180m. Might be worth checking with KJ. Sent from my GT-I9100 using Tapatalk __________________ Jesus don't want me for a sunbeam
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September 24th, 2012, 06:07 PM	#9 (permalink)
mikel-deko New Member Join Date: Mar 2012 Location: Basque Country Posts: 41 Thanks: 5 Thanked 6 Times in 4 Posts	Quote: (Originally Posted by lizardland) IIRC Hammerhead handsets are rated to 600ft/180m. Might be worth checking with KJ. Sent from my GT-I9100 using Tapatalk Thanks, i will check it.
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