1 logo variations Recommended Practice Center log for Soldering of No-Lead Alloys Construction Global European Institute 15 x 7x 4x 7x 4x 11 x 2x 7x 3x 6x 17 x 3x 5x 8x 18 x 15 x 147 x Latin America Brazil Chile International The Center logos shall Background bebrazil used in federally full. Themandated logos by implementation Latin Chile On January 4, 2014always new requirements, of Reduction of Lead in Drinking Water America Act (RLDWA), dramatically changed definition of no-lead as it appears in Safe Drinking Water Act (SDWA). Alliance shall never be moved or adjusted. Always use approved artwork when Previously SDWA definition of lead-free set a maximum limit for lead in pipes, fittings and valves utilized in potable water reproducing a Center logo. plumbing applications to a maximum of 8% total lead content, as a percentage of total mass of component. Now, rar than defining lead-free by total composition of alloy or component, RLDWA defines no-lead compliance by Center limiting amount of lead in contactlogo with potable water, rar than entire composition of component. By The Center is a intended for potable water use is limited new Act amount of lead allowed in alogo component Peru Mexico to a maximum of 0.25% lead calculated as a weighted average of total surface area of component in contact with water (wetted surface area). combination of three elements: ComponentsInternational include pipe, pipe fittings, valves and plumbing fittings. Cu mark, Center Peru name and. Mexico Industry wide, copper based alloys like brass and bronze are most widely used materials for valves, backflow Alliance Alliancepreventers and or plumbing fittings and faucets. The dramatic reduction in allowable lead content affects chemical composition should of copper alloys likethe brasses and Center bronzesname that can be used for potable water applications, as well as design of components using se alloys. never be separated from mark or altered in any way. Canada ExtraBold Canadian &only Brass The custom font is allowed to Development be used when creating Center logos. The font is custom spaced for logos and not suitable for use on communication elements. North America Development Inc.
2 Results of Changes to SDWA The change in allowable limits for lead in piping components can be addressed in two ways. First, components can be redesigned to reduce wetted surface area of lead bearing components below 0.25% limit of total wetted surface area. For example, a brass-body ball valve with a stainless steel ball may still utilize a brass alloy containing up to 8% lead ( limit in SDWA), provided that wetted surface area of that alloy is minimized so that weighted average lead content of total wetted surface area ( body plus ball) does not exceed 0.25%. Second, component manufacturers can incorporate into ir designs alternative copper (brass and bronze) alloys that do not contain lead, or contain significantly less lead. To aid in this effort a number of new copper alloys have been developed that substitute bismuth, silicon, and or alloys for lead to create functional, no-lead copper (brass and bronze) alloys. However, newer no-lead copper alloys can exhibit properties that are significantly different from older leaded copper alloys. In particular, differences in rmal conductivity of some of se alloys, especially those containing silicon, may lead to issues with solderability or joinability of se alloys in field. Background: Installation Concerns For well over a year CDA, ir representatives and members have been made aware of concerns related to solderability of no-lead alloys by installers of soldered joints between copper tube and se new no-lead copper alloys. In many cases, reported issues have come along with a variety of ories, misconceptions and myths as to root cause, and thus solution to issue. These myths include, among ors: Mechanical cleaning of no-lead alloy with a fitting brush leads to inferior solder joints FALSE Only specific soldering fluxes can be successfully used in joining no-lead alloys - FALSE Tinning fluxes must be used to join no-lead alloys - FALSE Heating entire joint with a larger torch to quickly bring entire assembly up to temperature is necessary - FALSE Joints must be immediately quenched following soldering to cool no-lead alloy and keep solder from running out of joint FALSE In case it isn t obvious enough, all of above are false. High quality solder joints can be made between copper tube and components made of new no-lead alloys using any previously acceptable cleaning method, any of commonly used and code-accepted soldering fluxes, using appropriately sized torch tips and without shock-cooling joint. So is solderability of new no-lead alloys truly problematic? While we wouldn t characterize it as problematic, soldering se new alloys can be more challenging, especially when soldering techniques are applied that do not meet industry standard recommendations as published in ASTM B828. Some of se no-lead alloys are less-forgiving of improper techniques or shortcuts that many installers have grown used to employing with more forgiving joints, such as copper tube to wrought copper fittings. Issue: Thermal Conductivity and Heating Process The challenge in making solder joints with se alloys lies in a fundamental misunderstanding of rmal properties of alloys and ir subsequent effects on solder joint fabrication. Thorough testing of all of variables involved in making solder joints between copper tube and new no-lead alloys including: various base alloys, cleaning methods, fluxes used, size of torch tips employed, order of heating joint components, post soldering quenching and ors, and application of se results to basic ory of solder joint design and fabrication supports this conclusion. In short, much lower rmal conductivity of se alloys, especially silicon-containing alloys, requires strict attention to proper heating and soldering procedure to ensure high-quality solder joints. After over a year of in-field and laboratory research, Development (CDA) is convinced installers concerns are directly related to a misunderstanding or in many cases misapplication of industry standard soldering procedure. This misapplication can have a negative impact on quality of solder joints made using se lower conductivity, no-lead alloys. The negative experience of installers regarding soldered joints in se alloys has very little to do with preparation of soldered joints or type of flux or solder used in fabricating soldered joints. In fact, while we could replicate apparent issues related to all of variables in joints made with improper soldering procedures, once we employed proper soldering procedure apparent impact of all of se variables disappeared. CDA has been recognized industry expert for over 50 years on use and application of copper and copper alloys in many applications and especially joining of copper and copper alloys. CDA was instrumental in research and development of soldering standard referenced in every major model plumbing and mechanical code in US. That standard is ASTM B828 - Standard Practice for Making Capillary Joints by Soldering of and Alloy Tube and Fittings. ASTM B828 outlines proven practices required to ensure fabrication of consistent 2
3 and repeatable high-quality soldered joints between copper and copper alloy tube, fittings and components. The standard contains several steps that must be completed for every soldered joint: 1. Measuring and cutting 2. Reaming (burr removal from I.D. and O.D.) 3. Cleaning (oxide removal from surfaces to be soldered) 4. Fluxing (thin even film of an approved flux applied to surfaces to be soldered) 5. Assembly and support (ensure equal capillary space around circumference of joint) 6. Heating (heating of tube, fitting and capillary space to bring each joint element up to soldering temperature) 7. Application of solder (to displace flux from joint and fill joint with solder) 8. Cooling & cleaning (uniform natural cooling and removal of excess flux following completion of soldering process, never quick quench) In case of joining copper tube to new, no-lead alloys particular attention must be paid to step six, heating process for making soldered joint. It is important for installers to thoroughly understand science and metallurgy associated with fabricating any soldered capillary joint. A capillary soldered joint between copper tube and copper or a copper alloy fitting is actually made up of four individual major parts that make up a soldered assembly: 1. Tube 2. Capillary space 3. Fitting, valve, or appurtenance ( alloy backflow preventer, pressure reducing valve, etc.) 4. Filler metal (solder) All four of se components of soldered joint have distinct and varying physical characteristics, like rmal conductivity, that must be taken into account individually as part of complete assembly. It is incorrect and problematic to view all four components as a single homogeneous assembly when fabricating soldered joints. In order to successfully create a high-quality soldered joint, all four parts of joint have to be at or above temperature where filler metal will melt, adhere to base metals (tube and fitting/component), and flow completely into and fill capillary space in that portion of joint by capillary action. Not only do all of se components need to reach a temperature at which solder will melt and flow, y must remain at this temperature to prevent premature freezing or solidification of solder metal before it is able to wet and spread throughout entire capillary space. It is not enough to simply heat solder with torch until it reaches melting temperature. The base metals (tube and fitting/component) must be raised to at or above melting temperature of solder and maintained at that temperature so that solder will be drawn into capillary space between two. Therefore, heating processes must be designed and applied to ensure that all components of joint assembly are raised to at or above melting point of solder and held at that temperature until solder has filled capillary space in that portion of joint. The soldering process outlined in ASTM B828 standard, CDA Tube Handbook, and AWS Soldering Handbook are all same, and is designed ensure proper heating to create a reliable, high-quality soldered joint. Unfortunately, based on traditional practices this process is rarely employed accurately or consistently in field. The inherent forgiveness of joints between copper tube to wrought copper fittings or no longer acceptable lead-bearing copper alloy (brass or bronze) has allowed installers to devise and employ substandard techniques and still achieve acceptable soldered joints. This is primarily due to very high rmal conductivity of wrought copper materials and lead-bearing copper alloys (see Table 1 below). The high conductivity of se parts virtually ensured that no matter where heat was applied to joint, on tube surface or fitting/component surface, heat from torch would have a high probability of bringing both of base metal components and capillary space up to soldering temperature. Improper heating of se joints, and especially improper heat control during application of solder metal is still a leading cause of faulty solder joints. Even though y are more forgiving y are not foolproof and proper techniques should still be followed, see ASTM B828. In-field research with various and multiple installers, training facilities and contractors throughout United States over past year confirms that installers are commonly employing improper heating techniques across range of solder joints that y install, including those made with new, no-lead alloys. The most common of se are improper application of preheat (location and duration) and improper application of heat during application of solder (location and duration). In first case, installers begin heating joint by applying torch directly to fitting/component cup and ignoring tube, attempting to bring entire joint assembly up to soldering temperature through application of heat only to fitting/ component. In second case, once joint or a portion of joint is at soldering temperature installers tend to focus all of heat at one point at base of fitting/component cup while solder is applied eir at one point or around entire joint. Let us evaluate problems associated with improper application of heat in se two cases. 3
4 Improper Preheating If we only try to heat joint through fitting re are several factors that are acting to disrupt easy and clear flow of heat into three parts of joint (tube, capillary space and fitting/component). The main disrupting factor is rmal conductivity, or ability to transfer heat through a material. When applying torch flame directly on fitting/ component heat that is being transferred from torch to fitting/component would have to heat fitting/component to soldering temperature, travel through fitting/component, n capillary space (an air space that acts like an insulator) and finally into tube, n bringing tube up to soldering temperature. In this case, as installer focuses heat only on fitting/component, with no prior preheating into tube, fitting/component cup begins to expand thus opening capillary space and increasing insulative effect of this space. This effect by itself greatly slows ability of torch to raise tube surface inside joint to soldering temperature. In addition, some of new no-lead copper alloys (brass or bronze) and especially silicon containing alloys have a coefficient of rmal conductivity almost 10 times lower (See Table 1 below) than copper tube, and 2 3 times lower than previous brasses and bronzes greatly slow transfer of heat through and out of fitting/component. Because of this, much more heat must be directed into fitting/component body to begin to raise temperature of tube surfaces within joint. This excessive application of heat required at fitting/component surface has shown four probable outcomes: 1. The fitting/component surface reaches soldering temperature but tube surface within joint does not, so solder melts and adheres to face of joint (due to some heat overwash on tube surface outside joint) but does not flow into capillary space; 2. The fitting component/surface reaches soldering temperature and tube surface inside joint barely reaches soldering temperature. The solder begins to melt and inherently cool joint surfaces so tube surface does not maintain soldering temperature. Solder solidifies without completely flowing/filling capillary space; 3. The fitting/component surface reaches soldering Draft Rev. 7 temperature 10 and February tube 2014 surface within joint reach soldering temperature but it took so much time to bring tube surfaces up to temperature that flux within Table 1: Coefficient of Thermal Conductivity of Tube and Select Leaded and No-Lead Alloys Table 1: Coefficient of Thermal Conductivity of Tube and Select Leaded and No-Lead (Brasses and Bronzes). No-lead alloys are highlighted. Alloys (Brasses and Bronzes). No-lead alloys are highlighted (*). UNS Alloy Number Common Name/Use Coefficient of Thermal Conductivity BTU x ft/(hr x ft 2 x 68 F C12200* DHP (copper tube and fittings) 196 A C36000 Free Cutting Brass (fittings, valves, components) 67 A C37700 Forging Brass (fittings, valves, components) 69 A C83600 Ounce Metal (fittings, valves, components) 41.6 A C84400 Valve metal (valves, components) 41.8 A C27450* Yellow Brass (fittings, valves, components) 67 A C69300* C89550* C89836* ECO Brass (fittings, valves, components) contains silicon as lead replacement SeBiLOY III (fittings, valves, components) contains bismuth and selenium as lead replacement Bismuth (fittings, valves, components) contains bismuth as lead replacement 21.8 A 58 (see note 1) 41.0 B Carbon (Black) Steel Included for comparison purposes 21 C 4 Sources: A ASM Handbook, Volume 2: Properties and Selection of Nonferrous Alloys and Special-Purpose Materials; ASM International: Miami, Florida B Alloy Data Sheet Sipi Metals Corporation; Chicago, Illinois Sources: A C ASM Handbook, Volume 1: Properties 2: Properties and Selection and Selection of Irons, Steels of Nonferrous and High Performance Alloys and Alloys; Special-Purpose ASM International: Materials; Miami, Florida ASM International: Miami, Florida Notes: 1 The rmal conductivity of C89550 has not been published. Due to close similarity of alloy composition this value is an extrapolation based on B Alloy Data Sheet Sipi Metals Corporation; Chicago, Illinois C ASM rmal Handbook, conductivity Volume of alloy C : Properties as found and in Source Selection A. of Irons, Steels and High Performance Alloys; ASM International: Miami, Florida
5 joint burns and inhibits effective flow of solder throughout capillary space; 4. Both fitting/component surface and tube surface within joint reach soldering temperature, solder flows throughout capillary space. However, excessive heat now contained in fitting/component surface due to excessive overheating and low rmal conductivity of material prevents joint from cooling quickly. This prevents solder in capillary space from freezing/ solidifying in space to complete joint (i.e. molten solder metal runs out of joint). Improper Application of Heat During Application of Solder Figure 1: improperly Heated Solder Joint Brush marks from mechanical cleaning (stainless steel brush inserted in power drill) still evident in soldered surface indicating inadequate heat in tube surface leading to a lack of solder fill in capillary space. Provided that proper preheating technique is employed (see below) to overcome issues above, improper application of heat during soldering process once joint components are at melting temperature of solder can also result in faulty joints. While re are a number of scenarios that can come into play here, we are only going to discuss two most common: application of heat at only one point while solder is added to joint; and application of heat only to fitting/component surface while solder is applied, ignoring tube surface. 1. Application of heat at only one point (commonly base of fitting/component cup at bottom of joint) while solder is applied at opposite side of joint (commonly top of a horizontal joint) requires that temperature throughout entire fitting/component cup and joint surfaces between heat source and point of application of solder must be above melting point of solder. And, y must stay above melting temperature as solder is added and begins to flow around and cool joint. With lower conductivity alloys, this is difficult to achieve and generally results in one of four outcomes listed above. 2. Failure to regularly reapply heat to tube surface as solder is applied can result in rapid cooling of tube surfaces within joint as solder is applied and can cause incomplete solder flow in capillary space. Once preheating is achieved, it is necessary to focus application of heat at base of fitting/component cup to ensure filling of entire capillary space with solder. However, rmal conductivity of fitting/component is still low and will prevent maintaining temperature of tube when heat is only applied to fitting/component. Again, this can lead to one of four outcomes listed above. Regardless of manifestation of problem, or outcome, all of se issues basically stem from misapplication of heating process which is exacerbated by fact that lower rmal conductivity of some of new, no-lead alloys makes proper application of heat more important. Joints between Figure 2: Improperly Heated Solder Joint Incomplete solder flow in capillary space due to inadequate preheating of tube surface. copper tube and new no-lead alloys can be, quickly, easily and reliably fabricated so long as installer follows heating processes below to ensure that all joint components are brought to and held at soldering temperature throughout soldering process. Solution: Recommended and Accepted Joining Procedure Since our research indicates that factors such as tube cleaning, fluxes used, post-fabrication cooling, etc. are not essential variables in successfully making joints between copper tube and new, no-lead copper alloy (brass and bronze) fittings/components we are not going to cover all of preparation steps for solder joints here. Instead we are only going to focus on proper heating processes. For more information on proper preparation of solder joints refer to ASTM B828, CDA Tube Handbook (), or AWS Soldering Handbook. Once all preparatory steps are completed, tube is cleaned, fluxed and inserted into cleaned and fluxed fitting actual soldering process can begin. 5
6 Step One: Preheat Tube In order to overcome difficulties in trying to bring tube surface up to soldering temperature installers should first focus on adequately preheating tube to soldering temperature. This does two important things. First, copper tube has a high rmal conductivity, so heating tube surfaces immediately outside joint allows tube to easily conduct heat along tube surface within joint itself, thus raising temperature of tube from front to base of fitting/ component cup. Secondly, adding preheat to tube causes tube to expand radially into fitting/component cup, thus minimizing capillary space (gap) between tube and fitting and keeping that space within tolerances necessary to create capillary flow of molten solder metal. Our research has shown that with new, no-lead fittings/ components it is beneficial to preheat tube more than would normally be done. This begins to heat interior surfaces of fitting/component with heat from tube surface. The preheating of tube should be undertaken with appropriately sized torch tip directing flame perpendicular to tube, about same distance from fitting cup as length of tube that is inserted into solder cup (i.e. if fitting cup is 1 inch deep, preheat tube approximately 1 inch beyond face of joint). While re is no definitive time limit on preheating, tube should be preheated until flux at face of joint begins to become active (begin showing signs of cleaning tube/fitting surfaces). Step Two: Preheat Fitting/Component Once appropriate preheat has been applied to tube, move flame back onto fitting/component surface to base of fitting cup. Preheating of fitting is most effective if torch is directed from back of fitting cup to face of solder cup. This torch position directs greatest amount of heat from back of fitting cup towards face, where solder will be applied. This allows for primary flame of torch to concentrate heat into fitting/component while allowing secondary flame to keep tube surface at temperature (note: for larger tube/fitting sizes it is beneficial to move torch in a slow, continuous pattern from base of fitting cup to face of joint as you work your way around circumference of joint). By using this torch position it actually pulls surrounding air around torch flame, which provides a cooling effect to area behind torch flame and unsoldered side of joint. Due to variable environmental conditions it is difficult to describe and exact time or duration of preheating. However, since tube surfaces inside were already preheated and began to conduct heat into inner surfaces of fitting/component, required preheating time on fitting/component is usually less than that for tube. Watch for activity of flux at face of joint and test solder to see if it melts. If solder melts it is time to switch from preheating to actual soldering process. If it does not melt, remove solder and continue preheating. Step Three: Apply Heat and Solder Now that appropriate preheating has been accomplished, choose a spot on joint to begin soldering. On vertically oriented joints, starting point is irrelevant in terms of successful completion of joint so we will focus on slightly more difficult horizontal joint. For horizontal joints, move torch to base of fitting/component cup slightly off-center of bottom of joint (imagine 5 o clock or 7 o clock position if face of joint were face of a clock) and begin adding solder to face of joint at this same position. As solder begins to melt from heat contained in tube and fitting/component (not from direct heat of torch) push solder straight into joint. Push solder into joint at this position until capillary space is full at current position before you move (solder will begin to run from front of joint), n keeping position of torch at base of cup slightly ahead of position of solder metal move solder metal across bottom of joint. Move slowly but deliberately, as solder fills capillary space at point of application it will begin to run out of face of joint, your signal to continue moving. Continue across bottom of fitting/component and up opposite side of joint to top of fitting/component. Coming across bottom of joint and up or side, moving torch along with solder creates smooth, continuous flow of solder in capillary space. While applying solder move most intense heat from torch away from already soldered portions allowing solder to solidify. In case of horizontal joint, this creates a solder dam at bottom of joint. Now, return to point of beginning off-center of bottom of joint keeping torch at base of cup and slightly ahead of solder metal. Overlap starting position and solder up remaining side of joint. Move slowly and deliberately with torch always slightly ahead of solder metal to fill capillary space and prevent remelting of already soldered surfaces. Once you reach top of joint, overlap your previous ending position and n remove both torch and solder. Installers should try to maintain even heating of joint surfaces during soldering. This can be accomplished by moving torch closer or furr away from joint so that hotter or cooler portions of flame are being used. Remember, as you add solder to joint and it melts, it removes heat from 6
7 base metals and acts to cool joint. By continually adding solder and varying portion of torch flame directed at joint you should be able to maintain solder at a molten, but still pasty condition allowing for good control of solder application. Failure to regulate portion of torch flame impinging joint can quickly lead to eir overheating or premature cooling of joint. Step Four: Cooling and Cleaning The completed soldered joint should be allowed to cool slowly and naturally. Never quick cool or quench any soldered joint. The new, no-lead alloys may not reject heat as quickly as ir predecessors due to ir lower rmal conductivity. Therefore, by controlling amount of heat added to joint in preheating and making solder joint to bare minimum required to facilitate full solder melting and flow, solder will solidify and cool joint quickly once joint is complete and direct heat from torch is removed. Conclusion If proper procedures are followed, especially in preheating and heating process, consistent, high-quality solder joints can easily be achieved between copper tube and new, no-lead copper alloy (brass or bronze) fittings/components. Proper heating techniques outlined in this paper are applicable to creating any soldered copper joint and are in complete agreement with recommended and accepted procedures contained in coderequired ASTM B828 standard, AWS Soldering Handbook, and CDA Tube Handbook. For more details on complete soldering process including descriptive photographs and diagrams refer to eir of se three documents or visit to view an online or downloadable version of Tube Handbook. You will also be able to view a brief video of process outlined above for joining copper tube to new, no-lead fittings/components. References: 1. ASTM B828, Standard Practice for Making Capillary Joints by Soldering of and Alloy Tube and Fittings; ASTM International, West Conshohocken, Pennsylvania; 2. The Tube Handbook; Development Inc., New York, New York; 3. Soldering Handbook; American Welding Society, Miami, Florida; 4. ASM Handbook, Volume 2: Properties and Selection of Nonferrous Alloys and Special-Purpose Materials; ASM International, Materials Park, Ohio; Figure 3: Properly Completed Solder Joint Prepared identically to Figure 1. Brush marks from mechanical cleaning (stainless steel fitting brush inserted in power drill) no longer evident as proper heating allowed for complete solder flow and fill in capillary space. 7
8 Construction Global 15 x 7 x 4 x 7 x 4 x 11 x 2 x 7 x 3 x European Institute 6 x 17 x 3 x 5 x 8 x 18 x 15 x 147 x Brazil Peru Brazil Peru Chile The Center logos shall always be used in full. The logos shall never be moved or adjusted. Always use approved artwork when reproducing a Center logo. Center logo The Center logo is a combination of three elements: Cu mark, Center name and. The Center name should never be separated from mark or altered in any way. Latin America Chile Mexico North America Latin America Mexico Canada ExtraBold Canadian The custom & font Brass is only allowed to Development be used when creating Center logos. The font is custom spaced for logos and not suitable for use on communication elements. Development Inc. This data sheet has been prepared for use of engineers, designers and purchasing managers involved in selection, design or machining of copper rod alloys. It has been compiled from information supplied by testing, research, manufacturing, standards, and consulting organizations that Development Inc. believes to be competent sources for such data. However, CDA assumes no responsibility or liability of any kind in connection with data or its use by any person or organization and makes no representations or warranties of any kind reby. A XX/14