Q/A about Bryan Hauger Consulting 30 minute free consultation
Clients often ask us, "What kinds of questions can your plastic consultants answer in just 30 minutes?" To help answer that question, we've pulled a number of actual questions and answers from previous Q&A sessions. Still have some unanswered questions? Please contact us for a free 30 minute consultation so we can provide you with answers!
Pre-compounded Pipe Materials and Black Masterbatch
Q - Is it possible to produce pipe by adding black masterbatch with carbon black to natural resin in plant in accordance with the requirements in ASTM D2513-14e1, Section 4 and ASTM D3035-15, Section 5?
A - ISO 4427 requires the use of pre-compounded materials in the manufacturing of polyethylene (PE) pipe for water applications. The ASTM standards you have noted do not include a specific requirement to use pre-compounded materials and are therefore permissive of either pre-compounded materials or in-plant blending of natural resin with colorant compound. These standards are potentially less clear than they could be because they do not explicitly state that both methods of providing a fully compounded black pipe product are allowed. For a more complete discussion of the allowable use of in-plant blending, I would like to direct you to the September 2014, 70-page paper I prepared for the Electric Power Research Institute, which can be found as the first link on this page. Specifically, you can read section 4 which deals with this subject in some detail. Here is an excerpt from that report.
“Thus far, this Section has focused on either unpigmented polyethylene or the black polyethylene compound that is converted into HDPE pipes. Although some resin manufacturers provide polyethylene compound with carbon black already added, commonly called pre-compounded polyethylene compound, others provide natural resin and a resin that contains carbon black at levels significantly higher than 2.0 to 3.0 weight per cent. The resin manufacturer provides the pipe manufacturer with instructions for combining the two materials, the natural resin and the black pigment concentrate compound, often referred to as “salt and pepper” compounding. The instructions provided will likely include important manufacturing details such as the blending ratios of the two components, instructions for proper drying techniques for the pigment concentrate compound and information regarding the details of mixing and extrusion used to create desirable properties in finished HDPE pipes”.
Q - Is it possible to produce pipe by adding black masterbatch with carbon black to natural resin in plant in accordance with the requirements in ASTM D2513-14e1, Section 4 and ASTM D3035-15, Section 5?
A - ISO 4427 requires the use of pre-compounded materials in the manufacturing of polyethylene (PE) pipe for water applications. The ASTM standards you have noted do not include a specific requirement to use pre-compounded materials and are therefore permissive of either pre-compounded materials or in-plant blending of natural resin with colorant compound. These standards are potentially less clear than they could be because they do not explicitly state that both methods of providing a fully compounded black pipe product are allowed. For a more complete discussion of the allowable use of in-plant blending, I would like to direct you to the September 2014, 70-page paper I prepared for the Electric Power Research Institute, which can be found as the first link on this page. Specifically, you can read section 4 which deals with this subject in some detail. Here is an excerpt from that report.
“Thus far, this Section has focused on either unpigmented polyethylene or the black polyethylene compound that is converted into HDPE pipes. Although some resin manufacturers provide polyethylene compound with carbon black already added, commonly called pre-compounded polyethylene compound, others provide natural resin and a resin that contains carbon black at levels significantly higher than 2.0 to 3.0 weight per cent. The resin manufacturer provides the pipe manufacturer with instructions for combining the two materials, the natural resin and the black pigment concentrate compound, often referred to as “salt and pepper” compounding. The instructions provided will likely include important manufacturing details such as the blending ratios of the two components, instructions for proper drying techniques for the pigment concentrate compound and information regarding the details of mixing and extrusion used to create desirable properties in finished HDPE pipes”.
ASTM D2774-12
Q - We have a technical committee on plastic pipe and we are reviewing ASTM D2774-12. Section 1.1, reads “This practice governs procedures and references ASTM specifications for underground installation of thermoplastic pressure piping, 63 in. (1372-mm) nominal size and smaller…” Isn’t this conversion a mistake because 63 inches should be 1600 mm?
A – You are correct. 63 inches is 1600 mm. This is an error that should be corrected. The intent was to provide the metric equivalents and the value in mm is wrong.
Q - We have a technical committee on plastic pipe and we are reviewing ASTM D2774-12. Section 1.1, reads “This practice governs procedures and references ASTM specifications for underground installation of thermoplastic pressure piping, 63 in. (1372-mm) nominal size and smaller…” Isn’t this conversion a mistake because 63 inches should be 1600 mm?
A – You are correct. 63 inches is 1600 mm. This is an error that should be corrected. The intent was to provide the metric equivalents and the value in mm is wrong.
ASTM D1785 and the Virginia Residential Code M1601.1.2
Q - According to Virginia residential code M1601.1.2, could ASTM D 1785, Schedule 40 PVC pipe be used in underground duct systems?
A - Chapter 16 of the Virginia mechanical code dealing with ducting systems relates to “Duct systems serving heating, cooling and ventilation equipment”. Unfortunately, my opinion is that meeting the specifications of ASTM D 1785 Schedule 40 PVC is not sufficient to show conformity to Virginia residential code M1601.1.2 Underground duct systems. This mechanical code requires conformity with Cell class 12454 B as per ASTM D 1784 and external loading properties per ASTM D 2412. You must also conduct ASTM D2412 testing.
My reasoning for this conclusion follows;
Q - According to Virginia residential code M1601.1.2, could ASTM D 1785, Schedule 40 PVC pipe be used in underground duct systems?
A - Chapter 16 of the Virginia mechanical code dealing with ducting systems relates to “Duct systems serving heating, cooling and ventilation equipment”. Unfortunately, my opinion is that meeting the specifications of ASTM D 1785 Schedule 40 PVC is not sufficient to show conformity to Virginia residential code M1601.1.2 Underground duct systems. This mechanical code requires conformity with Cell class 12454 B as per ASTM D 1784 and external loading properties per ASTM D 2412. You must also conduct ASTM D2412 testing.
My reasoning for this conclusion follows;
- ASTM D1785 contains no requirements for testing according to D2412 and therefore, the potential performance characteristics under external loading, such as in a buried duct system can’t be demonstrated through conformance with this standard.
- The scope of ASTM D1785 states ”The products covered by this specification are intended for use with the distribution of pressurized liquids only, which are chemically compatible with the piping materials. Due to inherent hazards associated with testing components and systems with compressed air or other compressed gases some manufacturers do not allow pneumatic testing of their products. Consult with specific product/component manufacturers for their specific testing procedures prior to pneumatic testing”. My chief concern related to the “cross-over” use of a water pipe in a ducting / mechanical application relates to flame / fire ratings. It is very common that code requirements include some type of fire rating and it is very uncommon that water pipe includes a fire rating.
ASTM D1598 Sustained Pressure Testing to Determine Conformance under ASTM D1785 and ASTM D2241
Q - Can you please help me better understand how to conduct pressure testing of PVC pipes for ASTM 1785 AND ASTM D2241 under the standard TEST D1598? From what I understand, ASTM D1598 says to test the pipe under the required sustained pressure until it fails. How can I determine what is the pass mark / fail mark for that particular pipe if I don’t have a benchmark failure time for the particular pipe under test? For example, for ½” schedule 40 pvc pipes, the sustained pressure is 1250 psi. Under the sustained pressure test procedures, if the pipe fails in 2 hours, does the pipe meet the ASTM standard or not?
A - You have stated “How can I determine what is the pass mark / fail mark for that particular pipe if I don’t have a benchmark failure time for the particular pipe under test”? The pass/fail requirements for ASTM 1785 and ASTM D2241 are contained in those standards and you will also need to purchase ASTM 1785 and ASTM D2241 if you wish to know the minimum requirement for a passing result. ASTM D1598 is merely a test method – it tells you how to test. Product requirements are contained in the product standards. As an example, ASTM D1785 contains the sustained pressure requirements in section 6.2 which states “The pipe shall not fail, balloon, burst, or weep as defined in Test Method D1598, at the test pressures given in Tables 3-5 when tested in accordance with 8.4”. You then correctly point out that for material designation codes PVC1120, PVC1220 and PVC2120, in the ½” nominal diameter of schedule 40, the sustained pressure is 1250 psi. The time requirement is found in section 8.4 of this same standard which states, in part “Maintain the specimens at the pressure indicated for a period of 1000 h”. In your example, if the proper sustained pressure test procedure results in a pipe failure in 2 hours, then the pipe has failed to meet the minimum time requirement for ASTM F1785 although I would also quickly mention that section 8.4 calls for several replicate samples to be tested prior to determining the final pass/fail status. I believe that a more detailed reading of the appropriate sections of ASTM D1785 and D2241 will fully answer all of your questions. For the best ASTM D1598 testing equipment in North America, click for more information.
Q - Can you please help me better understand how to conduct pressure testing of PVC pipes for ASTM 1785 AND ASTM D2241 under the standard TEST D1598? From what I understand, ASTM D1598 says to test the pipe under the required sustained pressure until it fails. How can I determine what is the pass mark / fail mark for that particular pipe if I don’t have a benchmark failure time for the particular pipe under test? For example, for ½” schedule 40 pvc pipes, the sustained pressure is 1250 psi. Under the sustained pressure test procedures, if the pipe fails in 2 hours, does the pipe meet the ASTM standard or not?
A - You have stated “How can I determine what is the pass mark / fail mark for that particular pipe if I don’t have a benchmark failure time for the particular pipe under test”? The pass/fail requirements for ASTM 1785 and ASTM D2241 are contained in those standards and you will also need to purchase ASTM 1785 and ASTM D2241 if you wish to know the minimum requirement for a passing result. ASTM D1598 is merely a test method – it tells you how to test. Product requirements are contained in the product standards. As an example, ASTM D1785 contains the sustained pressure requirements in section 6.2 which states “The pipe shall not fail, balloon, burst, or weep as defined in Test Method D1598, at the test pressures given in Tables 3-5 when tested in accordance with 8.4”. You then correctly point out that for material designation codes PVC1120, PVC1220 and PVC2120, in the ½” nominal diameter of schedule 40, the sustained pressure is 1250 psi. The time requirement is found in section 8.4 of this same standard which states, in part “Maintain the specimens at the pressure indicated for a period of 1000 h”. In your example, if the proper sustained pressure test procedure results in a pipe failure in 2 hours, then the pipe has failed to meet the minimum time requirement for ASTM F1785 although I would also quickly mention that section 8.4 calls for several replicate samples to be tested prior to determining the final pass/fail status. I believe that a more detailed reading of the appropriate sections of ASTM D1785 and D2241 will fully answer all of your questions. For the best ASTM D1598 testing equipment in North America, click for more information.
Several Questions about ASTM D2846 CPVC Pipe and Fittings
Q1. What is the difference between ASTM D2846 and ASTM D2846M?
A1. There is only one standard – ASTM D2846/D2846M. The M designation indicates that there is a true metric sizing system included in the body of the standard – especially there is a table of dimensions in which the metric values in the table establish the explicit dimension of the product rather than being merely a conversion from English (Imperial) measurements in inches. For example, reviewing Table 1 from the 2014 edition, we see that there is a note A which explains “All dimensions are in inches and millimetres”. Therefore the values in parenthesis for millimeters are precise dimensional requirements for the metric sizes 10, 15, 20, 25, etc.
Q2. From ASTM D2846, I would like to specify the wall thickness of size ½” (15 mm) SDR 11. How to specify the wall thickness of size ½” (15 mm) SDR 11?
A2. From the previous answer, it should now be clear to you that D2846 has explicit dimensional requirements for BOTH a ½” Nominal pipe size AND a 15 mm pipe size. The minimum wall thickness for the ½” SDR 11 size is found in the first position in the column as 0.060 inches. Conversely, if you wish to find the minimum wall thickness for the 15 mm pipe size, it is in the second position in that column and is shown as 1.52 mm.
Q3. What does it mean “D – wall thickness minimums are not a function of SDR”?
A3. This is a note in the same table which indicates that the dimensions on wall thickness are ABSOLUTELY defined by the dimensions shown in the table and may not necessarily reflect the mathematical calculation one might get from dividing the – for example – minimum outside diameter by 11 to obtain the value for the minimum wall thickness. Returning to the ½” size, we see that the minimum OD for this size is 0.622 inches. One might anticipate a minimum wall thickness therefore of 0.622 / 11 or 0.057 inches. Instead, the value is 0.060 minimum wall thickness as shown in the Table.
Q4. How do I test for conformance with ASTM D2846 section 6.1.3.2 “The maximum angular variation of any socket opening shall not exceed 1⁄2 ° off the true centerline axis”?
A4. Review of D2846 shows that this requirement has been present in the standard for several decades, and it goes back at least as far 1986 without any modification. However, this requirement is problematic since the standard does not proscribe a test method to make this measurement. Other subsections within section 6 of the standard give requirements for dimension and tolerances along with a citation to the test method for measurement. We are not aware of any test methods to measure the angular displacement from the centerline axis. Therefore, we believe that this section of the standard should be modified with the requirement removed but included instead as a non-mandatory note to provide manufacturing and design guidance.
Q1. What is the difference between ASTM D2846 and ASTM D2846M?
A1. There is only one standard – ASTM D2846/D2846M. The M designation indicates that there is a true metric sizing system included in the body of the standard – especially there is a table of dimensions in which the metric values in the table establish the explicit dimension of the product rather than being merely a conversion from English (Imperial) measurements in inches. For example, reviewing Table 1 from the 2014 edition, we see that there is a note A which explains “All dimensions are in inches and millimetres”. Therefore the values in parenthesis for millimeters are precise dimensional requirements for the metric sizes 10, 15, 20, 25, etc.
Q2. From ASTM D2846, I would like to specify the wall thickness of size ½” (15 mm) SDR 11. How to specify the wall thickness of size ½” (15 mm) SDR 11?
A2. From the previous answer, it should now be clear to you that D2846 has explicit dimensional requirements for BOTH a ½” Nominal pipe size AND a 15 mm pipe size. The minimum wall thickness for the ½” SDR 11 size is found in the first position in the column as 0.060 inches. Conversely, if you wish to find the minimum wall thickness for the 15 mm pipe size, it is in the second position in that column and is shown as 1.52 mm.
Q3. What does it mean “D – wall thickness minimums are not a function of SDR”?
A3. This is a note in the same table which indicates that the dimensions on wall thickness are ABSOLUTELY defined by the dimensions shown in the table and may not necessarily reflect the mathematical calculation one might get from dividing the – for example – minimum outside diameter by 11 to obtain the value for the minimum wall thickness. Returning to the ½” size, we see that the minimum OD for this size is 0.622 inches. One might anticipate a minimum wall thickness therefore of 0.622 / 11 or 0.057 inches. Instead, the value is 0.060 minimum wall thickness as shown in the Table.
Q4. How do I test for conformance with ASTM D2846 section 6.1.3.2 “The maximum angular variation of any socket opening shall not exceed 1⁄2 ° off the true centerline axis”?
A4. Review of D2846 shows that this requirement has been present in the standard for several decades, and it goes back at least as far 1986 without any modification. However, this requirement is problematic since the standard does not proscribe a test method to make this measurement. Other subsections within section 6 of the standard give requirements for dimension and tolerances along with a citation to the test method for measurement. We are not aware of any test methods to measure the angular displacement from the centerline axis. Therefore, we believe that this section of the standard should be modified with the requirement removed but included instead as a non-mandatory note to provide manufacturing and design guidance.
The Scope of ASTM D2467
Q - My question is about the application of ASTM D2467 regarding PVC Schedule 80 Plastic Pipe Fittings. In the Classification (section 4) of this ASTM, article 4.1.2, it is mentioned that fittings fabricated by back welding or butt fusion are not included in this ASTM. I understand that this implies that fittings fabricated by other methods, such as solvent welding for example, are actually included in this ASTM. Is my understanding correct?
A - I think it is important to understand the meaning of 4.1.2 which states what types of fittings are not included within the context of 4.1.1 which states what types of fittings are intended to be covered by the specification. 4.1.1 states “Fittings covered by this specification are normally molded. In-line fittings, such as couplings, unions, bushings, caps, nipples, and the like, shall be molded or machined from extruded stock”. The heat fusion joining methods mentioned in 4.1.2 are historically not accepted practices for joining of PVC pipes although more recently at least one North American company has reported creating joints in PVC pipe using such a procedure. Clearly, section 4.1.1 indicates that the intent of D2467 is to provide requirements for fittings which are either molded or machined. I believe that the standard is ambiguous regarding solvent welding neither expressly eliminating solvent welding from inclusion in the standard or clearly indicating its inclusion. While not clearly allowed as a method for fabricating fittings, it should also be noted that solvent joining methods are completely acceptable for joining ASTM D2467 fittings to PVC pipe such as described in ASTM D2855 titled “Standard Practice for the Two-Step (Primer and Solvent Cement) Method of Joining Poly (Vinyl Chloride) (PVC) or Chlorinated Poly(Vinyl Chloride) (CPVC) Pipe and Piping Components with Tapered Sockets”. Section 1.5 of this practice states “A partial list of standards for PVC and CPVC pipe, piping components, and solvent cements suitable for use in joining pipe and fittings is given in Appendix X1”. Appendix X1 of the document then lists ASTM D2467.
Q - My question is about the application of ASTM D2467 regarding PVC Schedule 80 Plastic Pipe Fittings. In the Classification (section 4) of this ASTM, article 4.1.2, it is mentioned that fittings fabricated by back welding or butt fusion are not included in this ASTM. I understand that this implies that fittings fabricated by other methods, such as solvent welding for example, are actually included in this ASTM. Is my understanding correct?
A - I think it is important to understand the meaning of 4.1.2 which states what types of fittings are not included within the context of 4.1.1 which states what types of fittings are intended to be covered by the specification. 4.1.1 states “Fittings covered by this specification are normally molded. In-line fittings, such as couplings, unions, bushings, caps, nipples, and the like, shall be molded or machined from extruded stock”. The heat fusion joining methods mentioned in 4.1.2 are historically not accepted practices for joining of PVC pipes although more recently at least one North American company has reported creating joints in PVC pipe using such a procedure. Clearly, section 4.1.1 indicates that the intent of D2467 is to provide requirements for fittings which are either molded or machined. I believe that the standard is ambiguous regarding solvent welding neither expressly eliminating solvent welding from inclusion in the standard or clearly indicating its inclusion. While not clearly allowed as a method for fabricating fittings, it should also be noted that solvent joining methods are completely acceptable for joining ASTM D2467 fittings to PVC pipe such as described in ASTM D2855 titled “Standard Practice for the Two-Step (Primer and Solvent Cement) Method of Joining Poly (Vinyl Chloride) (PVC) or Chlorinated Poly(Vinyl Chloride) (CPVC) Pipe and Piping Components with Tapered Sockets”. Section 1.5 of this practice states “A partial list of standards for PVC and CPVC pipe, piping components, and solvent cements suitable for use in joining pipe and fittings is given in Appendix X1”. Appendix X1 of the document then lists ASTM D2467.
ASTM D2467 In F1973, Section 6.3.1
Q - My question is about F1973, Section 6.3.1. The standard specifies that Pipe threads should conform to ASME B1.20.1 (NPT threads). Is it the intention of the standard to exclude the use of NPTF threads which conform to B1.20.3? Alternately, is it acceptable to the subcommittee to allow for the use of NPTF threads?
A - Since the standard specifies that only ASME B1.20.1 (NPT threads) are acceptable, then we should understand that is the explicit limit of the standard as currently approved. There is no disclarity or allowance for other thread types as written and the B1.20.3 threads should be understood to be outside of the scope of the standard. This requirement may not be arbitrary. There is a general concern in threaded fittings for natural gas distribution that the threads are “closed end threads” that do not create any potential pathway for a gas leak from the thread itself. I’m not certain if this makes good sense to you or if the B1.20.3 threads meet this application requirement. But I presume that the manufacturers would be able to give you more information. Both George Fischer Central Plastics and Continental Industries manufacture products which comply with F1973. If the exclusion of the B1.20.3 threads is an oversight or arbitrary, then the standard can be revised by action of members of the sub-committee. But if the exclusion of the B1.20.3 threads is intentional due to the concerns I mentioned previously, then I believe both of those sub-committee members could let you know and discuss the issue in more detail.
Q - My question is about F1973, Section 6.3.1. The standard specifies that Pipe threads should conform to ASME B1.20.1 (NPT threads). Is it the intention of the standard to exclude the use of NPTF threads which conform to B1.20.3? Alternately, is it acceptable to the subcommittee to allow for the use of NPTF threads?
A - Since the standard specifies that only ASME B1.20.1 (NPT threads) are acceptable, then we should understand that is the explicit limit of the standard as currently approved. There is no disclarity or allowance for other thread types as written and the B1.20.3 threads should be understood to be outside of the scope of the standard. This requirement may not be arbitrary. There is a general concern in threaded fittings for natural gas distribution that the threads are “closed end threads” that do not create any potential pathway for a gas leak from the thread itself. I’m not certain if this makes good sense to you or if the B1.20.3 threads meet this application requirement. But I presume that the manufacturers would be able to give you more information. Both George Fischer Central Plastics and Continental Industries manufacture products which comply with F1973. If the exclusion of the B1.20.3 threads is an oversight or arbitrary, then the standard can be revised by action of members of the sub-committee. But if the exclusion of the B1.20.3 threads is intentional due to the concerns I mentioned previously, then I believe both of those sub-committee members could let you know and discuss the issue in more detail.
Several Questions About Section 9.5 of ASTM D1598 - 15A
Q - In section 9.5 where it mentions the use of a check valve in a manifold system to prevent the depletion of the system when one specimen fails, can you please explain in detail what this means?
A - In this scenario a manifold implies a single pressure delivery system which shares the pressurization fluid among several samples. The clearest example I can think of is a traditional “Tee” configuration in which one pressurized fluid source might provide the fluid to two nearly identical samples. A check valve would close if one of the two branches of the tee ruptured to stop the flow of fluid. Here the intent is to ensure that the pressure to the second test specimen is not lower than the original pressure – or at least not lower for very long. If the supply flow is not much larger than the flow through the rupture, then pressure in the total system might drop slightly until the check valve can be shut. The use of a check valve in such a manner is completely allowed by the standard.
Q - Section 9.5 also implies that a failure is acceptable since it allows the use of check valves to prevent a failure from affecting the other specimens, but my understanding is that if ANY specimen fails during the test, it is considered an invalid test. Is this true?
A - Perhaps you are confusing ASTM D1599 with ASTM D1598. As the title implies, test pressures are selected in the ASTM D1598 test method usually in one of two ways – either a pressure is selected which is not expected to fail and the test is conducted to achieve a minimum number of hours OR a variety of pressures are selected under conditions which should force the pipe to fail in a reasonable amount of time (<1 year, often <1 month). So “failures” are the goal in the second type of testing and in that context are the expected result and totally acceptable. Perhaps a better term would be “rupture” of the pipe sample since this term doesn’t bring with it the same negative connotations often associated with the word “failure”.
Q - Section 9.5 also states that the use of a manifold system is acceptable providing each specimen has its own timing device. Can you explain this also? I am willing to incorporate these timing devices providing I understand what they are and where they would be located.
A - Without a separate timing device to each branch of the manifold, it would be difficult to accurately assess when the first rupture happens and how many hours the second sample has been exposed to pressure. It is clearly preferred to have a check valve that can automatically shut and a time which automatically stops when the pressure changes such as for the pipe rupture. In a fully automated system, the second timer can continue to seamlessly measure the time exposed to pressure for the second sample in spite of the first sample rupturing and the first timer stopping.
Q - In section 9.5 where it mentions the use of a check valve in a manifold system to prevent the depletion of the system when one specimen fails, can you please explain in detail what this means?
A - In this scenario a manifold implies a single pressure delivery system which shares the pressurization fluid among several samples. The clearest example I can think of is a traditional “Tee” configuration in which one pressurized fluid source might provide the fluid to two nearly identical samples. A check valve would close if one of the two branches of the tee ruptured to stop the flow of fluid. Here the intent is to ensure that the pressure to the second test specimen is not lower than the original pressure – or at least not lower for very long. If the supply flow is not much larger than the flow through the rupture, then pressure in the total system might drop slightly until the check valve can be shut. The use of a check valve in such a manner is completely allowed by the standard.
Q - Section 9.5 also implies that a failure is acceptable since it allows the use of check valves to prevent a failure from affecting the other specimens, but my understanding is that if ANY specimen fails during the test, it is considered an invalid test. Is this true?
A - Perhaps you are confusing ASTM D1599 with ASTM D1598. As the title implies, test pressures are selected in the ASTM D1598 test method usually in one of two ways – either a pressure is selected which is not expected to fail and the test is conducted to achieve a minimum number of hours OR a variety of pressures are selected under conditions which should force the pipe to fail in a reasonable amount of time (<1 year, often <1 month). So “failures” are the goal in the second type of testing and in that context are the expected result and totally acceptable. Perhaps a better term would be “rupture” of the pipe sample since this term doesn’t bring with it the same negative connotations often associated with the word “failure”.
Q - Section 9.5 also states that the use of a manifold system is acceptable providing each specimen has its own timing device. Can you explain this also? I am willing to incorporate these timing devices providing I understand what they are and where they would be located.
A - Without a separate timing device to each branch of the manifold, it would be difficult to accurately assess when the first rupture happens and how many hours the second sample has been exposed to pressure. It is clearly preferred to have a check valve that can automatically shut and a time which automatically stops when the pressure changes such as for the pipe rupture. In a fully automated system, the second timer can continue to seamlessly measure the time exposed to pressure for the second sample in spite of the first sample rupturing and the first timer stopping.
ISO EN Standards
Q - Do US laws/standards allow the installation of those products manufactured according to ISO EN standards?
A -As it relates to your question on plumbing materials, it is not federal law or even standards that create the hurdle for plastic piping materials and systems certified to ISO standards – even ISO EN standards. Rather it is the building codes. There are three North American Codes that have potential significant market impact for plumbing products; the uniform plumbing code, the international building code and the National Plumbing Code of Canada.
As an example, the UPC 2012 has on page 97 a big table for “Materials for Building Supply and Water Distribution Piping and Fittings” which lists all of the approved materials by standard. The table contains lots of ASTM and some CSA standards but no ISO standards. I believe the largest issue is not actually the standards themselves but the drinking water regulations. The US and Canada both recognize NSF 61 standard for drinking water. However, ISO standards use an EU certification for drinking water. Of course, there is also an issue relating to sizing with the US and Canada using a variety of English sizing systems including both Iron Pipe Size (IPS) and Copper Tubing Size (CTS). Some standards also include metric. If you can find an ASTM standard that includes a metric sizing system, then all that is needed is a product certification project to certify the product according to the applicable ASTM standard through a number of agencies with NSF, CSA and IAPMO being the largest. If there is no metric sizing system for the applicable standard, then there is a need to have the manufacturer create the new and compliant size or to add a table of metric sizes to the ASTM standard. Then the certification work can start. Of course, NSF 61 does not apply to any pipes aside from drinking water pipes.
Q - If not, are there any ASTM standards that are already related to
A - ISO EN 1519 appears to apply to paints and varnishes. Perhaps this is a typographical error.
ISO EN 1451 sub- references DIN 8078 for PP pipe and fittings. I don’t have a copy so I wasn’t able to do a close study for you on this short answer.
PEX-AL-PEX pipes are manufactured according to ISO EN 21003. I refer you to ASTM F1281 Standard Specification for PEX-AL-PEX Pressure Pipe and ASTM F1974 Specification for Metal Insert Fittings for Polyethylene/Aluminum/Polyethylene and Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene Composite Pressure Pipe. These standards include tables which I believe may represent standard metric tubing dimensions. Unfortunately, this standard may also include very specific wall thickness and aluminum thickness dimensions which a pipe manufacturer should closely review.
ASTM F876 (PEX) and ASTM F2389 (PP (including PP-RCT)) are two current standards which have significant manufacturing interests outside of the US and which are accepted in the building codes.
It is not uncommon that European pipe and fittings manufacturers conduct projects to obtain certification according to ASTM standards. Unfortunately, these are often lengthy, complicated and costly technical projects. There are a variety of consultants and consulting firms to assist companies in navigating this process for North American certification and sales.
Q - Do US laws/standards allow the installation of those products manufactured according to ISO EN standards?
A -As it relates to your question on plumbing materials, it is not federal law or even standards that create the hurdle for plastic piping materials and systems certified to ISO standards – even ISO EN standards. Rather it is the building codes. There are three North American Codes that have potential significant market impact for plumbing products; the uniform plumbing code, the international building code and the National Plumbing Code of Canada.
As an example, the UPC 2012 has on page 97 a big table for “Materials for Building Supply and Water Distribution Piping and Fittings” which lists all of the approved materials by standard. The table contains lots of ASTM and some CSA standards but no ISO standards. I believe the largest issue is not actually the standards themselves but the drinking water regulations. The US and Canada both recognize NSF 61 standard for drinking water. However, ISO standards use an EU certification for drinking water. Of course, there is also an issue relating to sizing with the US and Canada using a variety of English sizing systems including both Iron Pipe Size (IPS) and Copper Tubing Size (CTS). Some standards also include metric. If you can find an ASTM standard that includes a metric sizing system, then all that is needed is a product certification project to certify the product according to the applicable ASTM standard through a number of agencies with NSF, CSA and IAPMO being the largest. If there is no metric sizing system for the applicable standard, then there is a need to have the manufacturer create the new and compliant size or to add a table of metric sizes to the ASTM standard. Then the certification work can start. Of course, NSF 61 does not apply to any pipes aside from drinking water pipes.
Q - If not, are there any ASTM standards that are already related to
- HDPE pipes and fittings for waste sewage system are manufactured according to the ISO EN 1519 standard;
- PP pipes & fittings for waste sewage system are manufactured according to ISO EN 1451;
- Multilayer PEX-AL-PEX pipes are manufactured according to ISO EN 21003 standard.
A - ISO EN 1519 appears to apply to paints and varnishes. Perhaps this is a typographical error.
ISO EN 1451 sub- references DIN 8078 for PP pipe and fittings. I don’t have a copy so I wasn’t able to do a close study for you on this short answer.
PEX-AL-PEX pipes are manufactured according to ISO EN 21003. I refer you to ASTM F1281 Standard Specification for PEX-AL-PEX Pressure Pipe and ASTM F1974 Specification for Metal Insert Fittings for Polyethylene/Aluminum/Polyethylene and Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene Composite Pressure Pipe. These standards include tables which I believe may represent standard metric tubing dimensions. Unfortunately, this standard may also include very specific wall thickness and aluminum thickness dimensions which a pipe manufacturer should closely review.
ASTM F876 (PEX) and ASTM F2389 (PP (including PP-RCT)) are two current standards which have significant manufacturing interests outside of the US and which are accepted in the building codes.
It is not uncommon that European pipe and fittings manufacturers conduct projects to obtain certification according to ASTM standards. Unfortunately, these are often lengthy, complicated and costly technical projects. There are a variety of consultants and consulting firms to assist companies in navigating this process for North American certification and sales.
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