frogman62
Contributor
All, I have for sale the 1801 ($34.50) and 1803 ($43.50) re-packable replacement cartridges .
Sheldensportinggoods.com
Jim Shelden 316-992-0505
Sheldensportinggoods.com
Jim Shelden 316-992-0505
33'' tower problem {mako pd1803}
- Thread starter phantomrfa
- Start date
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I'm pleased it all turned out OK for you I'm just interested in the cost and all the work done.
What did the ultrasonic testing cost you? in addition what was the total cost to buy, test and repair this second hand filter.
Also did they do any other "testing" in addition to ultrasonic?
You would also have a ultrasonic test report, again out of interest can you post a copy of it.
On the report it should also tell you the test equipment used (it should) say for example under equipment used: "Wells Krautkramer USM
or a Krautkramer DM5 both are "ultrasonic" engineering tools but each shows different testing aspects.
Incidentally I am also interested how they repaired the .5 to.75mm deep corrosion pit on the 0-ring contact line and if the tower was re-
anodised in with the repair process. Iain Middlebrook
OP
phantomrfa
Registered
As i understand it the ultra sonic testing was to test for cracks around the ail rust and thread areas.
they cleaned the spot and filled it (with what i dont know) and then pressure tested it.
it has left a grey filled area. By the way this is a hydrolic company i used ,so i think they where a bit lost..
no paper work just cash in hand .. And yes it would have been cheaper to buy new, but i would have missed all the fun.
they cleaned the spot and filled it (with what i dont know) and then pressure tested it.
it has left a grey filled area. By the way this is a hydrolic company i used ,so i think they where a bit lost..
no paper work just cash in hand .. And yes it would have been cheaper to buy new, but i would have missed all the fun.
Pitting corrosion is where it starts but its inter-granular corrosion that originates cracking.
Now I don't know your filter material but I'm assuming its 7076 and as such may have been hard anodised however if its a coloured anodise finish blue gold red grey etc then it isn't hard anodise but soft.
Now its been covered probably with probably an epoxy metal putty knowing the hydraulic industry it is now susceptible to inter-granular corrosion under the cover so to speak.
Stress corrosion cracking of aluminium alloys is another thing to look out for again not knowing the material but alloys containing silicone, zinc, copper and magnesium are susceptible
The well known key factors are high water vapour, organic liquids, and pressure cycling.
The danger is that stress cracking can be achieved at far lower levels with the above factors than at the stresses required for yield.
Not wishing to alarm you but I don't think the outfit you used were up to the job. Further an E-bay purchase as an overseas customer is IMHO is asking for trouble.
You have no idea where this filter came from, if it had not already been scrapped been involved in a filter fire, how old it is, how many pressure cycles it's done and with no documentation, or verifiable history.
The company who took your cash for the repair behaved poorly also you should have been better informed.
In summary the job "never happened" Did they ask you the working pressure, or the pressure design code, the cyclic loadings or did they just jack the pressure for cash?
This is one good reason to use diving forums but preferably before you pay money.
Corrosion of the 0-ring contact line in filter shells is systematic with poorly maintained compressors and as the photo below shows, you can see the example of poor or non existent maintenance.
The wall thickness is measured for depth with the ultrasonic tool also in the photo
Iain Middlebrook
Now I don't know your filter material but I'm assuming its 7076 and as such may have been hard anodised however if its a coloured anodise finish blue gold red grey etc then it isn't hard anodise but soft.
Now its been covered probably with probably an epoxy metal putty knowing the hydraulic industry it is now susceptible to inter-granular corrosion under the cover so to speak.
Stress corrosion cracking of aluminium alloys is another thing to look out for again not knowing the material but alloys containing silicone, zinc, copper and magnesium are susceptible
The well known key factors are high water vapour, organic liquids, and pressure cycling.
The danger is that stress cracking can be achieved at far lower levels with the above factors than at the stresses required for yield.
Not wishing to alarm you but I don't think the outfit you used were up to the job. Further an E-bay purchase as an overseas customer is IMHO is asking for trouble.
You have no idea where this filter came from, if it had not already been scrapped been involved in a filter fire, how old it is, how many pressure cycles it's done and with no documentation, or verifiable history.
The company who took your cash for the repair behaved poorly also you should have been better informed.
In summary the job "never happened" Did they ask you the working pressure, or the pressure design code, the cyclic loadings or did they just jack the pressure for cash?
This is one good reason to use diving forums but preferably before you pay money.
Corrosion of the 0-ring contact line in filter shells is systematic with poorly maintained compressors and as the photo below shows, you can see the example of poor or non existent maintenance.
The wall thickness is measured for depth with the ultrasonic tool also in the photo
Iain Middlebrook
I have to agree with iain, you are potentially taking a huge risk using a filter which has visible corrosion. Corrosion can be the beginning of stress fractures. Not sure about the UK, but in the US, visible internal corrosion can be cause for immediately condemning a cylinder. In fact, a visual inspection is required by law because it has been proven to prevent more accidents than a hydro or any other test. Aluminum is more susceptible to unexpected failure from very tiny defects than steel. I remember reading an accident report about an aluminum cylinder that exploded because it had a microscopic defect in the threads (from the factory) that ended up traveling and causing catastrophic rupture. I have never heard of any sort of filler material that would prevent crack propagation.
Aluminum is susceptible to fatigue cracking simply due to age. The recommended lifetime of an aluminum pressure vessel is no more than 15-20 years. If yours is that old, I would pitch it for that reason alone. These filter assemblies store a very large amount of energy and can rupture and kill you without apparent cause. I've read reports of aluminum cylinders passing a hydro and immediately exploding upon the first fill thereafter (luxfer cylinders in the 70's with sustained loading fatigue problems).
I highly recommend these filters from safe air systems. They are stainless steel, don't corrode and are of very high quality. You'll sleep better at night
Stainless Stell Breathing Air Purification Systems | Safe Air Systems Safe Air Systems
Aluminum is susceptible to fatigue cracking simply due to age. The recommended lifetime of an aluminum pressure vessel is no more than 15-20 years. If yours is that old, I would pitch it for that reason alone. These filter assemblies store a very large amount of energy and can rupture and kill you without apparent cause. I've read reports of aluminum cylinders passing a hydro and immediately exploding upon the first fill thereafter (luxfer cylinders in the 70's with sustained loading fatigue problems).
I highly recommend these filters from safe air systems. They are stainless steel, don't corrode and are of very high quality. You'll sleep better at night
Stainless Stell Breathing Air Purification Systems | Safe Air Systems Safe Air Systems
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