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Technical bulletins

Support item:

Luxfer does not require or recommend eddy-current

Luxfer Gas Cylinders has received questions from cylinder inspectors and users about whether it is necessary to use eddy-current devices to test Luxfer scuba cylinders made from aluminum alloy 6061 (AA6061). 

Eddy-current testing is used to detect sustained-load cracking (SLC) in aluminum alloy cylinders. The majority of Luxfer aluminum alloy cylinders in service today are made from Luxfer AA6061 alloy, which is not susceptible to SLC.

For all scuba cylinders made from Luxfer AA6061, the Luxfer manufacturer’s requirement is that cylinders conform to regulatory requirements for periodic inspection and testing in the countries in which cylinders are being used. Luxfer does not require or recommend eddy-current testing of these AA6061 cylinders. 

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OTV Technical Bulletin

Torques greater than the maximum specified are unnecessary and can damage the valve and in extreme over-torque cases might create unsafe conditions.

High over-torques can split the knob into 2 or 3 pieces. A cracked or split knob does not affect valve sealing; however, it indicates excessive torque applied to the knob. Replace a cracked or split knob immediately.

Please see the attached PDF file for further support.

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Statement for UK Diving Industry

ALUMINIUM ALLOY CYLINDERS FOR UNDERWATER BREATHING APPARATUS

Statement for UK Diving Industry – March 2018

1. All Luxfer cylinders manufactured from aluminium alloys AA6351 and HE30/AA6082 and used primarily for gases for underwater breathing apparatus must undergo a thorough visual inspection by a trained, properly qualified inspector and be tested with an eddy-current device, in addition to testing required by the regulatory authority, at the time of periodic inspection and testing. Cylinders manufactured from these alloys are known to be susceptible to sustained-load cracking (SLC). Cylinders to be inspected and tested include those used for SCUBA diving, those that supply breathing air through an umbilical hose and those used to fill SCUBA cylinders. Failure to conduct such inspection and testing could result in serious harm.

2. Luxfer-required eddy-current testing is in addition to any other testing normally done during periodic inspection and testing. Luxfer approves two eddy-current devices, Visual Plus? and Visual Eddy™, for such testing. Periodic inspection and testing of these cylinders should occur at least every five years.

3. For Luxfer underwater breathing apparatus cylinders made from aluminium alloy 6061 (AA6061), Luxfer’s manufacturer’s requirement is that every five years a cylinder be visually inspected by a qualified inspector and also undergo testing required by the regulatory authority. Luxfer does not require eddy-current testing of Luxfer underwater breathing apparatus cylinders made from Luxfer’s proprietary version of AA6061, which is marketed under the trade name Luxfer L6X® or as ‘6061 (a proprietary blend)’. The vast majority of Luxfer aluminium cylinders in service today are made from this alloy, which is not susceptible to SLC.

4. Luxfer does not object to more frequent visual inspection of diving cylinders, typically annually or every 2.5 years, if the diving industry and/or regulatory authorities believe it useful to promote safety. Luxfer has supported such choices of the industry and regulatory authorities in the past and continues to do so.

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Recall notification

The following serial numbers of Luxfer medical oxygen cylinder model ME24 with an original hydrostatic test date of 08/15 are under recall by Luxfer Gas Cylinders. The reason for the recall is that the cylinders may fall outside of the design specification.

If you find that you are in possession of any cylinders on this list, please contact Luxfer Gas Cylinders customer service toll-free at 800-764-0366 for information regarding the return of cylinders to Luxfer.

This recall does not affect any other Luxfer products outside of the list or original manufacture date of 08/15.

BX302116

BX302118

BX302143

BX302200

BX302237

BX302250

BX302251

BX302253

BX302261

BX302264

BX302266

BX302267

BX302271

BX302273

BX302275

BX302276

BX302277

BX302278

BX302279

BX302280

BX302281

BX302282

BX302283

BX302284

BX302285

BX302286

BX302287

BX302288

BX302289

BX302290

BX302291

BX302292

BX302293

BX302294

BX302295

BX302296

BX302297

BX302298

BX302300

BX302301

BX302302

BX302303

BX302304

BX302305

BX302306

BX302307

BX302308

BX302309

BX302310

BX302312

BX302314

BX302315

BX302316

BX302317

BX302318

BX302319

BX302320

BX302321

BX302322

BX302323

BX302324

BX302325

BX302326

BX302328

BX302329

BX302330

BX302331

BX302332

BX302333

BX302334

BX302337

BX302338

BX302339

BX302340

BX302341

BX302344

BX302345

BX302346

BX302347

BX302348

BX302351

BX302352

BX302353

BX302354

BX302355

BX302356

BX302357

BX302385

BX302416

BX302439

BX302440

BX302476

BX302499

BX302534

BX302564

BX302629

BX302647

BX302663

BX302673

BX302684

BX302721

BX302836

BX302856

BX302872

BX302926

BX302930

BX302948

BX303037

BX303150

BX303160

BX303201

BX303213

BX303224

BX303252

BX303258

BX303269

BX303274

BX303316

BX303345

BX303355

BX303375

BX303388

BX303394

BX303440

BX303447

BX303483

BX303493

BX303506

BX303507

BX303514

BX303517

BX303543

BX303547

BX303565

BX303570

BX303580

BX303620

BX303628

BX303633

BX303637

BX303647

BX303655

BX303657

BX303664

BX303666

BX303681

BX303693

BX303699

BX303701

BX303704

BX303706

BX303720

BX303731

BX303734

BX303740

BX303743

BX303745

BX303747

BX303750

BX303751

BX303752

BX303759

BX303760

BX303836

BX303863

BX303878

BX303882

BX303999

BX304125

BX304199

BX304200

BX304201

BX304203

BX304205

BX304249

BX304287

BX304289

BX304294

BX304299

BX304313

BX304325

BX304326

BX304327

BX304328

BX304341

BX304352

BX304375

BX304377

BX304394

BX304422

BX304469

BX304519

BX304521

BX304522

BX304526

BX304532

BX304547

BX304549

BX304603

BX304606

BX304608

BX304617

BX304644

BX304646

BX304648

BX304667

BX304681

BX304688

BX304690

BX304696

BX304697

BX304716

BX304723

BX304725

BX304792

BX304807

BX304813

BX304868

BX304882

BX304960

BX304967

BX304969

BX304971

BX304976

BX304982

BX304986

BX304989

BX304990

BX304991

BX305002

BX305003

BX305007

BX305008

BX305013

BX305016

BX305023

BX305026

BX305027

BX305029

BX305031

BX305034

BX305394

BX305401

BX305477

BX305485

BX305516

BX305548

BX305549

BX305551

BX305571

BX305756

BX305768

BX306001

BX306002

BX306003

BX306004

BX306005

BX306006

BX306008

BX306010

BX306014

BX306020

BX306022

BX306023

BX306026

BX306027

BX306029

BX306030

BX306034

BX306037

BX306043

BX306060

BX306072

BX306097

BX306099

BX306112

BX306115

BX306116

BX306122

BX306131

BX308075

BX308076

BX308078

BX308080

BX308081

BX308083

BX308084

BX308085

BX308088

BX308089

BX308090

BX308091

BX308093

BX308094

BX308095

BX308096

BX308097

BX308098

BX308099

BX308100

BX308102

BX308103

BX308104

BX308105

BX308106

BX308108

BX308109

BX308110

BX308111

BX308112

BX308113

BX308114

BX308115

BX308117

BX308119

BX308120

BX308121

BX308122

BX308123

BX308126

BX308127

BX308128

BX308129

BX308130

BX308131

BX308132

BX308133

BX308134

BX308135

BX308138

BX308139

BX308140

BX308141

BX308142

BX308143

BX308144

BX308145

BX308146

BX308147

BX308148

BX308149

BX308150

BX308151

BX308152

BX308153

BX308154

BX308156

BX308157

BX308159

BX308161

BX308162

BX308163

BX308164

BX308166

BX308167

BX308168

BX308170

BX308172

Support item:

MRI compatibility of Luxfer aluminum and composite medical cylinders

Luxfer Gas Cylinders sometimes receives inquiries about whether our aluminum and aluminum-lined composite medical cylinders are MRI compatible. The term "MR or MRI Compatible" has been superseded by the current ASTM International terminology: "MR Conditional," which is defined as "an item that has been demonstrated to pose no known hazards in a specified MRI environment with specified conditions of use." Field conditions that define a particular MRI environment include static magnetic field strength, spatial gradient, dB/dt (time varying magnetic fields), radio frequency (RF) fields and specific absorption rate (SAR).

Whichever term is used, the question remains: Can Luxfer medical cylinders be safely used in close proximity to magnetic resonance imaging (MRI) and other types of medical equipment that emit magnetic fields? The general answer to that question is: Yes.

In addition to our own testing, Luxfer commissioned in-depth third-party testing of our medical cylinders, covering all combinations of aluminum alloy and monolithic/composite construction. The third-party test report concluded: "For each cylinder tested, no apparent magnetic field interactions were detected under the conditional used for testing. Thus, each cylinder product may be considered 'MR Conditional at 3-Tesla or less.'"

Please note that Luxfer's statement and the cited test results apply only to Luxfer aluminum alloy and composite cylinders and do not apply to valves, regulators, handles, carts or any other equipment that may be either attached to or used in combination with Luxfer cylinders. Always ensure that any such ancillary equipment also meets ASTM or other applicable safety criteria for use in proximity to MRI equipment.

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Luxfer position concerning life extension of DOT CFFC carbon composite cylinders

For more than a decade, Luxfer has actively researched this matter and participated in detailed deliberations involving DOT, the Compressed Gas Association (CGA) and other cylinder manufacturers to obtain a service-life extension. However, DOT declined to approve life extension for these cylinders. Consequently, Luxfer decided not to pursue this effort further and to take a different approach to providing cylinders with longer service life.

Background

In 1996, DOT issued its CCFC-1 standard that established basic requirements for design, manufacture and performance of cylinders consisting of seamless aluminum liners over-wrapped with structural layers of filament-wound carbon fiber and epoxy composite material. At that time, DOT offered the possibility of extending the 15-year service life of such cylinders "up to a total service life of 30 years." To obtain an extension, a cylinder manufacturer was required to submit for DOT approval a "Service Life Extension Plan" that would meet certain criteria. Soon after CCFC-1 was issued, Luxfer and other U.S. cylinder manufacturers individually submitted such life-extension plans to DOT. However, DOT accepted none of these plans and declined to extend cylinder service life.

In response, cylinder manufacturers attempted an industry-wide approach to obtain DOT approval under the auspices of a special CGA task group, but the service life was not extended.

Luxfer's longer-life composite cylinder

In 2006, Luxfer began developing a new, more robust cylinder designed for a service life longer than 15 years. This new cylinder was based on ISO 11119, an international design standard. In August 2008, DOT granted Luxfer special permit 14232 (SP14232), which authorizes the manufacture of these cylinders for use in the United States.

While cylinders made under SP14232 are designed for service lives as long as 30 years, the special permit explicitly sets forth certain testing and validation requirements that must be met before the service life of any cylinder may be extended beyond 15 years. As of the issue date of this bulletin, no cylinder manufactured under SP14232 has thus far been approved for a service life longer than 15 years since these cylinders have not yet reached the age at which their service life will be eligible for extension.

For more information, please use the DOT links below or contact Luxfer Gas Cylinders at 951-341-2348.

U.S. Department of Transportation special permits searchDOT-CFFC (Basic requirements for fully-wrapped carbon fiber reinforced aluminum-lined)

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Sustained-load cracking (SLC) in ruptured scuba cylinder made from 6351 aluminum alloy

SLC is a thoroughly researched and well-documented metallurgical phenomenon that occasionally develops in cylinders made from 6351 alloy, as well as in other types of pressure vessels and structural components under stress for sustained periods of time. SLC has occurred in cylinders manufactured by various companies, including Luxfer. Cylinders that have been mechanically damaged, over-filled or otherwise abused are more susceptible to SLC, which is not a manufacturing defect, but a phenomenon inherent in the metal itself.

Research has consistently shown that sustained-load cracks grow very slowly, typically taking eight or more years to grow large enough to cause a cylinder leak or, in extremely rare cases, a rupture. Because SLC growth is so slow, properly trained inspectors have adequate opportunity to detect cracks and remove cylinders from service during normal annual inspections or as part of the DOT-required requalification process every five years. Both Luxfer and DOT have long maintained that proper, diligent inspection by correctly trained personnel is the best way to avoid cylinder-related accidents.

It is important to note that SLC has occurred only in a small number of older cylinders made from 6351 aluminum alloy. Cylinders made from 6061 aluminum alloy, the metal currently used by all U.S. manufacturers, have not exhibited SLC.

Luxfer discontinued use of 6351 alloy in June 1988 and since that time has only manufactured scuba cylinders from Luxfer’s proprietary L6X® formula for 6061 aluminum alloy. Out of more than 40 million cylinders, no Luxfer cylinder made from L6X® (6061) alloy has ever exhibited a sustained-load crack.

For more detailed information about SLC, visit the Luxfer website at www.luxfercylinders.com, click “Support” on the top menu bar, click “Frequently Asked Questions” on the left-hand menu and then click the “Sustained-load Cracking (SLC)” heading. For specific dates when Luxfer switched different cylinder models from 6351 to 6061 alloy, click “Support,” then “Technical Bulletins” and scroll down to Dates when Luxfer changed its aluminum alloy from 6351 to 6061 (posted November 12, 2003).

If you have additional questions, call Luxfer’s toll-free customer service line: 800-764-0366.

1See Department of Transportation: HM-220F, Federal Register, Vol. 71, No. 167, pages 51122-51129.

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Paint removal and repainting of Luxfer all-metal and composite cylinders made from 6061 aluminum alloy (L6X®)

Preparation

All-metal Luxfer 6061 aluminum alloy (L6X®) cylinders1—To remove paint from an all-metal cylinder and prepare the surface for repainting, blast with plastic, glass or other soft media just long enough to remove most of the old paint. Do not blast with sand, steel, grit or aluminum oxide media, which are too abrasive. Heavy or improper blasting with hard or overly abrasive media removes metal as well as paint from the cylinder, which can thin the cylinder wall and make the cylinder unsafe to fill or use. Improper blasting also obliterates stamped markings and damages the outer surface of the cylinder.

Never use corrosive, caustic or acidic paint strippers or solvents to remove paint. Never use burning or torching techniques. Do not use knives or other sharp instruments to remove labels.

Once paint has been removed, use a neutral, mild, water-based detergent to wash the cylinder. Rinse the cylinder well and thoroughly dry it at a metal temperature not exceeding 160 degrees F (70 degrees C). Carefully inspect the cylinder surface for damage and corrosion in accordance with all applicable regulations. If the cylinder passes the inspection, it is ready for repainting.

Composite cylinders—Do not attempt to remove intact old paint from composite cylinders by blasting or any other means that may damage the cylinder exterior. Lightly rub the surface with fine-grit emery paper to prepare it for repainting. If the surface is dirty, clean it with a neutral, mild, water-based detergent, then rinse it well and dry it thoroughly.

Never use corrosive, caustic or acidic paint strippers or solvents to remove paint or to clean composite cylinders. Never use burning or torching techniques. Do not use knives or other sharp instruments to remove labels.

Once the outer surface of the cylinder is clean, inspect it for damage in accordance with all applicable regulations. If the cylinder passes the inspection, it is ready for repainting.

All cylinder types—Do not use the above preparatory processes on the internal surface and thread area of any Luxfer cylinder. Different processes (not covered by this document) should be used to clean threads and internal surfaces.

While preparing a cylinder exterior for painting, take care not to damage the valve connection area or cylinder threads. Do not allow any process materials (e.g., cleaning agents, blast media, grit, etc.) to contaminate the threads and inside of the cylinder.

Painting

All-metal Luxfer 6061 aluminum alloy (L6X®) cylinders—Do not use acidic or caustic paints that may damage the cylinder exterior. You may use any neutral, air-drying or aliphatic, water-based or solvent-based liquid paint that is compatible with aluminum. You may also use neutral, aluminum-compatible powder coatings as long as curing temperatures and exposure times do not exceed those recommended by Luxfer. Please note that different aluminum alloys have different maximum-temperature specifications; for example, for Luxfer 6061-alloy (L6X®) cylinders, the maximum metal temperature must not exceed 350ºF (175ºC). Exposure times at various temperatures vary according to alloy. Please contact Luxfer for time/temperature information about the particular cylinder and alloy that you intend to repaint using powder coatings. Cylinders subjected to temperatures and exposure times exceeding Luxfer recommendations or heated to unknown temperatures must pass hydrostatic tests before being filled or used.

Composite cylinders—Use flame-retardant, air-drying or aliphatic, water-based or solvent-based epoxy or polyurethane liquid paints on Luxfer composite cylinders. Do not heat cylinders to speed up curing or drying of paint. Do not use powder coatings or other coatings that must be heated or baked. Never expose composite cylinders to heat exceeding 180ºF (82ºC).

Do not paint over cylinder labels. Mask labels before painting and make sure that they remain legible. (Note: Color coding cylinders to identify gas contents or usage does not eliminate the regulatory requirement for legible, properly configured labels.)

All cylinder types—Do not allow paint to contaminate the threads, valve connection area or internal surface of any Luxfer cylinder.

1Luxfer markets its proprietary version of 6061 aluminum alloy under the registered trade name L6X

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Luxfers Grundsatzerklärung hinsichtlich einer vorgeschlagenen längeren Nutzungsdauer von vollumwickelten Verbundflaschen

Gelegentlich erhält Luxfer Gas Cylinders Anfragen über die Möglichkeit, die Nutzungsdauer seiner vollumwickelten Composite-Flaschen zu verlängern.

Alle vollumwickelten Verbundflaschen von Luxfer sind für eine beschränkte Nutzungsdauer ausgelegt, in den meisten Fällen auf 15 Jahre. Derzeit gibt es keine Ausführungsbestimmungen für die Verlängerung der Nutzungsdauer von solchen Flaschen. Überdies hat die gewerberechtlich vorgeschriebene Beschränkungen der Nutzungsdauer zu der beispiellosen Sicherheit dieser Produkte beigetragen.

Aus diesem Grund besteht Luxfer Gas Cylinders auf seinen Unternehmensgrundsätzen und verlängert die Nutzungsdauer seiner Verbundflaschen nicht.

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Politique de Luxfer pour l’extension de la durée de vie des bouteilles bobinées en composite

Luxfer Gas Cylinders reçoit occasionnellement des demandes d’extension de durée de vie pour les bouteilles bobinées en composite de Luxfer.

L’ensemble des bouteilles bobinées en composite de Luxfer a été conçu pour une durée de vie spécifique, généralement limitée à 15 ans. Actuellement, aucune autorisation légale ne nous permet de prolonger la durée de vie de ces bouteilles. En outre, si ces produits enregistrent un niveau de sécurité exemplaire, c’est en partie grâce aux limites réglementant leur durée de vie.

C’est la raison pour laquelle la politique de la société Luxfer Gas Cylinders ne prévoit aucune extension de durée de vie des bouteilles en composite.

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Luxfer clarifies difference between bowed and bulged aluminum cylinders

Luxfer Gas Cylinders has received an increasing number of inquiries about the difference between “bowed” and “bulged” aluminum cylinders. The pictures and information below are intended to clarify this important difference.

Bowed Cylinder A bow is a slight curve in the sidewall of an aluminum cylinder (see image above). A fairly common cosmetic feature, a bow is not dangerous and does not affect cylinder performance. A bow is an occasional by-product of the manufacturing process, not a manufacturing defect. Bows occur most often in taller cylinders, including scuba cylinders with a capacity of 80 cubic feet or more. A typical bowed cylinder has one convex side curving slightly outward and an opposite concave side (180° degrees away) curving slightly inward. The curves are long and gradual, covering much of the length of the cylinder sidewall. Most bows are barely discernible with the naked eye, but they sometimes become noticeable when you hold a straight edge against the cylinder wall and rotate the cylinder to reveal both the convex and concave sides. More severely bowed cylinders are sometimes called “banana shaped,” and even these cylinders are safe to use. Infrequently a cylinder will have one straight side and one slightly convex (outward curving) side. Such a condition, called an unparallel sidewall or a plano-convexity, is also a type of bow. It does not affect cylinder performance. Inspectors should be careful not to misidentify the harmless, slightly convex side of a bowed cylinder as a bulge, which is completely different and a very rare condition.A bow is often so subtle that the naked eye has difficulty detecting it. (In the picture above, the bow has been exaggerated somewhat to make it clearly visible.) Using a straight edge will usually reveal convexity and concavity. Bear in mind that the convex (outward curving) side is sometimes more pronounced than the concave side. Do not mistake the convexity of a bow for a bulge! (For more information about bulges, see the following section.)

Bulged CylinderA bulge is an extremely rare, dangerous condition. Bulged cylinders must be immediately condemned and removed from service. Unlike a bow, which is usually slight and sometimes difficult to see, a bulge is generally very pronounced and obvious, even to the naked eye. Bulges occur in cylinders that have been overheated or in cylinders with sidewalls thinned by severe corrosion. There are two basic types of bulges. A long, convex bulge protrudes outward noticeably on one side or around the entire circumference of the cylinder; such a bulge occurs when an entire cylinder has been exposed to high heat. A smaller, “goose-egg-shaped” bulge usually indicates localized overheating, which is the result of “spot annealing.”

If you are uncertain whether a cylinder is bulged, remove it from service and contact Luxfer Customer Service before condemning the cylinder.

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Dates when Luxfer changed its aluminum alloy from 6351 to 6061

Between 1987 and 1988, Luxfer Gas Cylinders discontinued use of 6351 aluminum alloy and began using a proprietary version of 6061 aluminum alloy for all its aluminum cylinder models manufactured in the United States. Listed below are the dates by model number when the transitions to the new alloy occurred. Any current Luxfer models that do not appear on this list were never made from 6351 alloy in the first place and have always been made from Luxfer's proprietary 6061 alloy.

SCUBA

S30, S63 -May 1988

S40 - June 1988

S50, S92 - April 1988

S72, S100 - August 1987

S80 - January 1988

S808 - May1987

SCBA

L7, L8, L13 - September 1987

L13 - May 1988

L15 - January 1989

L26 - February 1988

L45 - November 1987

CO2

C1.2, C1.5 - January 1989

C2 - November 1988

C10 - August 1988

C5 - June 1988

C15 - November 1987

C20, C35 - April 1988

C50 - February 1988

Medical

M9 - January 1988

MD15, ME24 - December 1987

Industrial Gas

N22, N150 - May 1988

N33 - November 1988

N60, N122 - December 1987

N88 - December 1988