Download Technical Bulletin (Revised June 2012)
Hydrofluoric acid is an aggressive substance used in the stainless steel industry, usually to assist in removal of scale and the chrome depleted layer associated with welds.
Changes in the National Drugs and Poisons Schedules have recently brought hydrofluoric acid (HF) into focus.
Products containing HF in concentrations greater than one percent (1%) now attract a National Drugs and Poisons Schedule 7 listing. In many states this has implications for license and permit requirements. Further information on the background to rescheduling of HF from a Schedule 6 to a Schedule 7 poison, can be found at the National Drugs and Poisons Schedules Committee website.
The implications of this change for people purchasing and using "pickling pastes" (usually incorporating HF at concentrations between 3% and 5%) and other pickling materials containing HF, and for persons selling these materials, are briefly described below on a state by state basis. The descriptions are based on verbal and in some cases written discussion with the departmental office in each state or territory and are not provided as definitive statements on your responsibilities. Also included are contact details for Public Health Authorities in each state. If you use or trade HF-containing products, ASSDA strongly suggests you contact state authorities for further information, licence applications etc.
ASSDA made representation to the National Drugs and Poisons Scheduling Committee which ultimately led to a change in the regulatory requirements in New South Wales. This change is reflected below.
It is likely however that there are conditions which must be met right now to buy or sell HF products in most states. Although in some cases licenses and permits are inexpensive, there is still paperwork to be completed and additional checks to be implemented in organisations handling these products.
Failure to comply with these laws may trigger various legal alternatives open to state authorities. Failure to obtain the relevant license or permit may also have implications for an organisation's insurance cover or other risk management arrangements.
ASSDA urges you to examine your responsibilities and maintain compliance with appropriate laws.
AUSTRALIAN CAPITAL TERRITORY (ACT) Sellers or manufacturers of Schedule 7 poisons require a license, issued by the Minister (of Health), to possess a Schedule 7 substance. The current license fee is from $322 per year. Schedule 7 substances must be securely stored at all times and any sales must be recorded in a poisons register. |
NEW SOUTH WALES (NSW) t: 02 9879 3214 |
NORTHERN TERRITORY (NT) |
QUEENSLAND (QLD) Drug and Poisons Policy and Regulation Unit, Environmental Health Branch, Public Health Queensland t: 07 3328 9310 e: www.health.qld.gov.au A Schedule 7 poison may only be sold by a person who has been licensed by the Chief Executive Officer to do so. A licensee must ensure all Schedule 7 poisons are stored in a locked receptacle or storeroom, and keep personal possession of another responsible adult authorised by the licensee. A licensee must make accurate records of all sales of Schedule 7 poisons. These records may be made in the form of an entry in poisons sales book, or by giving the purchase an invoice that has a unique number. The following details must be recorded:
Usually a licensed wholesaler may not sell by retail. However, a licensed wholesaler may sell a Schedule 7 poison by retail to a person who uses the poison in a technical process connected with the person's business, industry or trade. The wholesaler must give the purchaser an invoice that has a unique number and states:
The application fee for license to sell a Schedule 7 poison is $265 and the renewal fee is $159. The application fee for a license to manufacture a Schedule 7 poison is $562.50, and the renewal fee is $456.50 a year. |
SOUTH AUSTRALIA (SA) Wholesalers of Schedule 7 poisons are required to be licensed. The license fee is $171 for 1 year. The license fee to manufacture a Schedule 7 is $255. Please note, fees change on 1 July annually. There are requirements for record-keeping associated with the license. Contact the SA Department of Health for further details and applications. |
TASMANIA (TAS) t: 03 6233 2064 Licenses are required by sellers of a Schedule 7 poison and by all purchasers. |
VICTORIA (VIC) t: 1300 364 545 or 03 9096 1067 Manufacturers and wholesalers require a license to trade Schedule 7 poisons. A license to manufacture a Schedule 7 poison costs $695.30 for the first year and $245.60 for subsequent years. Manufacturing the product is defined to include all activities such as preparing for sale, repackaging, relabeling etc. |
WESTERN AUSTRALIA (WA) t: 08 9222 6883 Licenses to sell permits to use are required for Schedule 7 poisons. Application for a wholesaler's license costs $600. To apply for a permit to use the product, the cost is $200. |
For many years there has not been a Standard to cover the low-pressure stainless steel cast pipe fittings commonly used in Australia and other countries around the world.
These are commonly termed “150lb” or “BSP” pipe fittings. In most cases the fittings that have been supplied were a mismatch of various Standards.
The fittings were dimensionally in accordance with a number of American Standards, whilst British Standard threads were used. This led to the fittings having threads that in some cases were non-compliant - basically there was insufficient length to accommodate the thread.
ASSDA, through its Technical Committee, identified this problem in the early 90s and through the publication of ASSDA’s Technical Bulletin No 1, highlighted the problems to the Australian market. ASSDA also looked for a mechanism to have these problems rectified.
ISO 4144 "Pipework - Stainless Steel Fittings Threaded in Accordance with ISO 7-1"
After investigating the alternatives it was decided that International Standard ISO 4144 could be the conduit to rectifying the problems. ISO 4144 in its 1979 form covered most of the committee’s concerns, but it did not allow for cast fittings - only wrought stainless steel.
After correspondence with the Australian and International Standard bodies, it was ascertained that ISO 4144 was due for revision, which presented a golden opportunity to have the standard rewritten to cover all of the Technical Committee’s concerns.
ASSDA was invited to represent Australia on the committee established to review the Standard and actively took part in the full process of its revision. Not all of the Committee’s recommendations were accepted. Finally, in early 2003 the new Standard was published.
What has been achieved?
The major improvements that have been adopted in the new Standard are:
a. The use of castings as well as wrought materials.
b. All cast fittings are to be properly heat-treated by solution annealing.
c. The reduction in dimension, a more economical fitting.
d. The thread standards allowed have been clearly defined.
e. An introduction of pressure-temperature ratings for application of the fittings.
f. The inclusion of eight new types of fittings into the Standard.
g. The inclusion of DN 100 (4”) fittings.
Now that ISO 4144:2003 allows for the use of castings, Australia finally has a Standard that covers the products that have been in common use for many years.
The requirement that all castings are to be fully heat-treated will alleviate some of the corrosion problems that have been encountered in the past.
The dimensions of the fittings have been revised dramatically, thus giving a lighter and more economical fitting.
The wall thickness is the major dimension that has been reduced and it can be reduced by a further 20% if the fitting is made from wrought material.
ISO 7-1 sealing pipe threads are to be used on all fittings. The external and internal threads are to be tapered, but the internal threads may be parallel. The only exception to this is the threads on the Unions and their mating nut, which are allowed to have a variety of parallel threads.
Pressure temperature ratings for application of fittings have been specified (refer to Table 1).
Some fitting types supplied into Australia were not covered in the old ISO 4144 Standard.
Eight new types have been included in the new Standard: these are 90° Reducing Female Elbows, Reducing Female Tees, 45° Equal Female Elbows, 90° Male x Female Elbows, Crosses, Reducing Nipples, Male x Female Unions and Male x Male Unions.
With the inclusion of the DN 100 (4”) fittings, the Standard now has a comprehensive range of products.
Some Disappointments with the New Standard
In the new Standard, apart from some minor editorial errors, there are two points of concern to the ASSDA Technical Committee.
Firstly, the new wall thicknesses that are stated as minimum could lead to a product being supplied that may not meet the expectations of the customer.
Even though the Standard allows for thin wall product, such thin walled fittings could be subject to distortion during the threading process or during installation. Care must be taken that this does not occur.
The second concern within the Standard is the length of the minimum external thread that has been adopted. The title of ISO 7-1 is “pipe threads where pressure tight joints are made on the threads”.
The minimum length specified can accommodate a thread that seals if it is manufactured to close tolerance. Care is required in manufacture to achieve this outcome.
Although it was recommended to the International Committee that it accept external thread lengths that could accommodate a thread at both ends of the tolerance range, the Committee did not adopt these recommendations.
Table 2 highlights the external thread lengths that were adopted compared to the external thread lengths that were recommended by Australia.
Conclusion
ASSDA believes minimum thread length is a concern to all suppliers and users of these fittings and care should be taken in their selection.
If mating fittings do not seal on the threads and interfere with the washout they may leak.
It is recommended that fittings should only be sourced from reputable and experienced manufacturers and supplied to ISO 4144:2003.
Overall, the Standard is a considerable improvement on what was available, and with care in the selection, the end user will be in a more certain and much safer environment than in the past.
Credits
This article was written by Kim Burton, Group Supply Manager of Prochem Pipeline Products Pty Ltd and an ASSDA Technical Committee member. ASSDA also acknowledges the contribution of Technical Committee member Peter Moore, Technical Services Manager of Atlas Specialty Metals, in the development of this article.
For many years there has not been a Standard to cover the low-pressure stainless steel cast pipe fittings commonly used in Australia and other countries around the world.
These are are commonly termed "150lb" or "BSP" pipe fittings. In most cases the fittings that have been supplied were a mismatch of various Standards.
The fittings were dimensionally in accordance with a number of American Standards, whilst British Standard threads were used. This led to the fittings having threads that in some cases were non-compliant - basically there was insufficient length to accommodate the thread.
ASSDA, through its Technical Committee, identified this problem in the early 90s and through the publication of ASSDA's Technical Bulletin No. 1, highlighted the problems to the Australian market. ASSDA also looked for a mechanism to have these problems rectified.
Hydrofluoric acid is an aggressive substance used in the stainless steel industry, usually to assist in removal of scale and the chrome depleted layer associated with welds. This Technical Bulletin outlines changes to drugs and poisons schedules and state-by-state contacts on the subject.
Continue reading here or download PDF copy.
Stainless steel is widely used in and around swimming pools and performs exceptionally well in most applications. However, some common types of stainless steel are not suitable for use in the airspace of indoor pool buildings in certain applications where they are subject to a tensile stress.
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