For Reference - Hose Specifications for Ships

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JK
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For Reference - Hose Specifications for Ships

Postby JK » Mon Jan 16, 2017 6:40 am

1. All hose is to be made of a long hole, surrounded by rubber centered around the hole. Holes are permitted on the outside as long as they fit circumferentially over the cover.
2. All hose is to be round and hollow throughout the entire length.
3. All hose is to be of the very best quality stuff, preferably tubular or hosular stuff.
4. All acid-proof hose is to be made of acid-proof rubber so the un-acid-proof holes won't fall through the very best stuff.
5. The ID of the hose must NOT exceed the OD, otherwise the hole will be on the outside of the hose.
6. All hose is to be supplied with nothing in the hole so that water, steam, or other stuff can be put inside at a later date.
7. All hose is to be supplied without abrasions, cuts, gashes, or gouges as these can be more readily added in the flex hose shop or on the ship.
8. All hose tubes are to be cleaned free of covering such as mud, tar, barnacles or any form of manure before the outer cover is added, as these objects will make the cover lumpy. The result is lumpular hose.
9. All hose over 500 feet in length but less than two miles must have the words "LONG HOSE" clearly painted on each end so that the pipefitter will know that it is a long hose. Hose over 2 miles in length must also have these words painted in the middle so that the pipefitter will not have to walk the entire length of the hose to determine if it is a long hose or not.
10. All hose over 6 inches in diameter is to have the words "LARGE HOSE" painted on it, so that the pipefitter will not use it for a small hose.

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Re: For Reference - Hose Specifications for Ships

Postby Revolver » Tue Jan 17, 2017 4:54 am

Having Lumpular hose is definitely a problem...

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Merlyn
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Re: For Reference - Hose Specifications for Ships

Postby Merlyn » Tue Jan 17, 2017 5:24 am

Interesting write up but I wonder if anyone out there could answer my question concerning air hoses.
Teeing off the main compressor thro' a regulator maybe and connecting a spray gun to it we would respray say a engine or gearbox parts we had just overhauled to " finish off the job properly " and make it look good.
( hence the saying, overhauled with a spray gun )
When much later the HP receiver was due an inspection and the manhole cover removed the colours you had used previously could clearly be seen on the tank internal walls.
Given maybe 30 bar ish upto the regulator then 30/40 psi onwards upto the gun how on earth could the paint run up against this to deposit itself onto the tank internals?
Some kind of reverse flow vortex arrangement?
Anyone?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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JollyJack
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Re: For Reference - Hose Specifications for Ships

Postby JollyJack » Tue Jan 17, 2017 7:55 am

Either speshul porous steel or metamorphosis.
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Merlyn
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Re: For Reference - Hose Specifications for Ships

Postby Merlyn » Tue Jan 17, 2017 8:33 am

Latin?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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Big Pete
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Re: For Reference - Hose Specifications for Ships

Postby Big Pete » Tue Jan 17, 2017 1:18 pm

Paint spray in the air drawn through the compressor as a fine aerosol?
Were the internals of the compressor also pretty colours when opened up?

Lucky the air compressor didn't start "Dieseling".

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Re: For Reference - Hose Specifications for Ships

Postby Merlyn » Wed Jan 18, 2017 12:34 am

Seem to remember the actuall spraying was 60 plus feet away from the compressor air inlet filter in a separate generator room so I don't remember any paintspray mist being drawn in induction wise.

It was all back in the sixties but I could never understand the " uphill travel " of the paint against airflow but I do remember when cutting the airline feed for air leakage repair purposes it showed the colour being used.
Must be some kind of weird formulae out there somewhere to explain all this?
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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Big Pete
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Re: For Reference - Hose Specifications for Ships

Postby Big Pete » Wed Jan 18, 2017 12:36 pm

Could be related to the old steady flow energy equation, as the velocity increases the pressure drops, so if you had a very high velocity of air flow leaving the air receiver and the pipe narrowed on its way to the sprayer, high initial Kinetic Energy (velocity) and low air pressure would be converted to a lower Kinetic energy (velocity) and higher pressure, creating a pressure gradient opposing the direction of flow. Even if the pipe was constant diameter, the same effect would occur every time the paint gun trigger was released, and the air flow through the sprayer stopped. Air would continue to flow towards the trigger because of its kinetic energy and would compress the air already at the trigger, this would only stop once the Kinetic energy stored in the flowing air in the pipe line had all been used up compressing air in front of the trigger, the air flow would then reverse and flow back into the air receiver, until the pressures were equalised and the flow stopped.
What sort of paint guns were they? Air blasting through a simple venturi and sucking the paint out of the drum/Pail?
If somehow paint was leaking into the air line at the trigger mechanism I could see how it would work its way back towards the air receiver.

BP.

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Merlyn
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Re: For Reference - Hose Specifications for Ships

Postby Merlyn » Thu Jan 19, 2017 12:39 am

Think they were a pot clipped onto a container with a steel tube projecting into the paint tin.
Probably as you say a Venturi effect discharge.
It was a proper spray gun of that era.
Allways imagined the HP flow through the centre of the pipe created some sort of backflow vacuum effect around possibly the sides of the pipe but I never really got to the bottom of it, always thought maybe when you snapped the gun trigger shut maybe some sort of backlash/ higher pressure transmitted itself back up the airline.
The trigger valve shutoff mechanisms would have to be faulty to allow this to carry the paint mist back up the line.
Another of one of life's mysterious happenings.
Bit like CR really in a different form.
It's just a Glitch we are told but it's never really explained properly.
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.

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Big Pete
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Re: For Reference - Hose Specifications for Ships

Postby Big Pete » Fri Jan 20, 2017 12:31 am

What I described with the pressure pulses in the air line when the air valve was rapidly shut is exactly what happens in a liquid line when a valve is closed quickly,known as "water hammer" then, big pressure pulses bouncing off the closed valve. Which is why you should always close Bunker valves slowly when Bunkering or loading oil cargoes.
It is always better to ask a stupid question than to do a stupid thing.


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