INSTALLATION STANDARD FOR WELDED COPPER AND COPPER ALLOY WATER TUBE IAPMO IS

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Jeremy Gibbs
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INSTALLATION STANDARD FOR WELDED COPPER AND COPPER ALLOY WATER TUBE IAPMO IS 21-2006 1.0 Scope.

1 INSTALLATION STANDARD FOR WELDED COPPER AND COPPER ALLOY WATER TUBE IAPMO IS Scope. This standard shall govern the installation of welded copper and copper alloy water tube in potable hot and cold water systems.installation, material, and inspection shall comply with the current edition of the Uniform Plumbing Code [UPC] TM published by the International Association of Plumbing and Mechanical Officials and this standard. Table ANSI B ANSI B ASTM B 447 Appendix A Referenced Standards Cast Copper Alloy Solder Joint Pressure Fittings Wrought Copper and Copper Alloy Solder Joint Pressure Fittings Welded Copper Tube Chart A 4.1 Friction Loss Note: The following sections of the Uniform Plumbing Code apply to welded copper and copper alloy water tube Testing of Systems Minimum Standards Workmanship Prohibited Fittings and Practices Protection of Piping, Materials, and Structures Hangers and Supports Increasers and Reducers Chapter 6 Water Supply and Distribution Materials Pipe, Tube, and Fittings Copper Tube Hard-Drawn Copper Tubing Flexible Copper Connectors Previously Used Piping and Tubing Copper Pipe, Tubing, and Joints Flared Joints Soldered Joints Joints Between Various Materials Copper Pipe or Tubing to Threaded Pipe Joints Drains Installation, Testing, Unions, and Location Size of Potable Water Piping Ground Joint, Flared, or Ferrule Connections Chemical Wastes Use of Copper Tubing 2.0 Product Requirements. 2.1 Minimum Standards Materials. Materials shall comply with the appropriate standard in Table of the UPC. Note: The nominal or standard size of copper and copper alloy welded water tube is always inch (3.8 mm) or 1 8 inch (3.8 mm) smaller than the actual outside diameter dimension of the tube. For example, 3 inch (76 mm) nominal size copper plumbing, tube measures inch (79.2 mm) O.D., 1 2 inch (12.7 mm) nominal size copper plumbing tube measures 5 8 inch (15.9 mm) O.D., etc. 2.2 Use of Copper Tubing Markings. Markings shall be visible for inspection Water tube shall bear the following incised marked at not over 18 inch (457 mm) intervals: (a) Manufacturer s name or trademark; (b) Tube type; and (c) Country of origin All hard drawn tube shall be identified throughout its entire length by a colored marking not less than 3 16 inch in height, including legend repeated at intervals not greater than 3 feet (914 mm). The legend shall include the type of tube, welded, ASTM specification, name or trademark of the manufacturer or both, and the country of origin. [UPC 604.3] (a) Tube listed by IAPMO that is covered by this standard shall be labeled with the designated IAPMO certification mark to show compliance with this standard MINNESOTA PLUMBING CODE 221

2 2.3 Joints General Information. Copper tube and fittings maybe joined in a number of ways, depending on the purpose of the system. Soldering and brazing with capillary fittings are the methods used most. The American Welding Society defines soldering as a joining process which takes place below 840 F (449 C) and brazing as a similar process which occurs above 840 F (449 C) but below the melting point of the base metals. In actual practice for copper systems, most soldering is done at temperatures ranging from about 350 F to 550 F (177 to 288 C), while most brazing is done at temperatures ranging from 1100 F to 1500 F (593 C to 816 C). The choice between soldering or brazing will generally depend on operating conditions. Solder joints are generally used where the service temperature does not exceed 205 F (96 C), while brazed joints can be used where greater strength is required, or where system temperatures are as high as 400 F (204 C). [UPC 605.3] Fittings for Soldered, Brazed, and Flared Joints. Fittings are available in all standard tube sizes and in a wide variety of types to cover needs for plumbing. They can be either soldered or brazed, although brazing cast fittings requires care. Wrought copper pressure fittings are also available over a wide range of sizes and types. These, too, can be joined by either soldering or brazing, and wrought fittings are preferred where brazing is the joining method. Otherwise, the choice between cast and wrought fittings is largely a matter of the user s preference. Flared-tube fittings provide metal-to-metal contact similar to ground joint unions; both can be easily taken apart and reassembled. They are especially useful where residual water cannot be removed from the tube and soldering is difficult. Flared joints may be required where a fire hazard exists and the use of a torch to make soldered or brazed joints is not allowed Solders. Note: Users of the Uniform Plumbing Codes are reminded that provisions of the Federal Clean Drinking Act of 1986, which all must obey, forbid the use of solder which contains in excess of 0.2% of lead, by weight in potable water systems. The provisions of the act are incorporated in all ordinances, statutes, state and municipal regulations by reference and by operation of law. The selection of a solder depends on the operating pressure and temperature of the line. Consideration should also be given to the stresses on the joint caused by thermal expansion and contraction. However, stresses due to temperature changes should not be significant in two commonly encountered cases: when tube lengths are short, or when expansion loops are used in long tube runs. Solder is generally used in wire form, but paste-type solders are also available. These are finely granulated solders in suspension in a paste flux. When using paste-type solders, observe these four rules: 1. Wire solder must be applied in addition to the paste to fill the voids and assist in displacing the flux, otherwise the surfaces may be well tinned and yet there may not be a good joint with a continuous bond. 2. The paste mixture must be thoroughly stirred if it has been standing in the can for more than a very short time, as the solder has a tendency to settle rapidly to the bottom. 3. The flux cannot be depended on to clean the tube. Cleaning should be done manually as is recommended for any other flux and solder. 4. Remove any excess flux. Solders are available containing small amounts of silver or other additives to impart special properties. Such solders may require special fluxes. The manufacturer s recommendations should be consulted regarding proper procedures and fluxes for such solders and about the expected properties Soldering Flux. The functions of the soldering flux are to remove residual traces of oxides, to promote wetting, and to protect the surfaces to be soldered from oxidation during heating. The flux should be applied to clean surfaces and only enough should be used to lightly coat the areas to be joined. An oxide film may reform quickly on copper after it has been cleaned. Therefore, the flux should be applied as soon as possible after cleaning. CAUTION Careless workmanship, especially during flux applications, can result in corrosion of the tube long after the system has been installed. If excessive flux is used, the residue inside the tube can cause corrosion. In an extreme case, such residual flux can actually lead to perforation through the tube wall causing leakage. To guard against this danger, it is important (1) to choose a flux that is not too corrosive, and (2) to use only the minimum amount actually needed to make the joint MINNESOTA PLUMBING CODE

3 2.3.5 Solder Joints. Soldering and brazing both involve basic steps, which must be executed with care and craftsmanship. The steps are: (1) Measuring (2) Cutting (3) Reaming (4) Cleaning (5) Fluxing (6) Assembly and support (7) Heating (8) Applying the filler metal (9) Cooling and cleaning Each step contributes to a strong, dependable joint Measuring. Measuring the length of each tube segment must be accurate. Inaccuracy can compromise joint quality. If the tube is too short it will not reach all the way into the socket of the fitting and a proper joint cannot be made. If the tube segment is too long, there is danger of cocking the tube in the fitting and putting strain on the system which could affect service life Cutting. Once the tube is measured it can be cut. Cutting can be accomplished in a number of different ways to produce a satisfactory square end. The tube can be cut with a disctype tube cutter, a hacksaw, an abrasive wheel, or with a stationary or portable bandsaw. Care must be taken that the tube is not deformed while being cut. Regardless of method, the cut must be square with the run of the tube so that the tube will seat properly in the fitting socket Reaming. All pipe and tube shall be reamed to the full I.D. of the pipe and tube. Tools used to ream tube ends include the reaming blade on the tube cutter, half-round or round files, a pocket knife, and a suitable deburring tool. With annealed tube, care must be taken not to deform the tube end by applying too much pressure. Both the inside and the outside of the tube may require removal of the burr Cleaning. The removal of oxides and surface soil is crucial if filler metal is to flow properly into the joint. Unremoved oxide, surface soil, and oil can interfere with the strength of the joint and cause failure. Mechanical cleaning is a simple operation. The end of the tube should be abraded lightly using sand cloth or nylon abrasive pads for a distance only slightly more than the depth of the fitting socket. The socket of the fitting should also be cleaned using sand cloth, abrasive pads, or a properly sized fitting brush. Copper is a relatively soft metal. If too much material is removed, a loose fit will result and interfere with satisfactory capillary action in making the joint. The capillary space between the tube and fitting is approximately inch (0.1 mm). Solder or brazing filler metal can fill this gap by capillary action. This spacing is critical for the filler metal to flow into the gap and form a strong joint. Surfaces, once cleaned, should not be touched with bare hands or oily gloves. Skin oils, lubricating oils, and grease impair solder flow and wetting Fluxing. Stir the flux before use. A good flux will dissolve and remove traces of oxide from the cleaned surfaces to be joined, protect the cleaned surfaces from reoxidation during heating and promote wetting of the surfaces by the solder. A thin, even coating of flux should be applied with a brush to both tube and fitting. Do not apply with fingers. Chemicals in the flux can be harmful if carried to the eyes or open cuts Assembly and Support. After both tube and fitting surfaces are properly fluxed, they should be assembled, making sure the tube seats against the base of the fitting socket. A slight twisting motion ensures even distribution by the flux. Remove excess flux. Care must be taken to assure that the tube and fittings are properly supported with a uniform capillary space around the entire circumference of the joint. Uniformity of capillary space will ensure good filler metal penetration if the guidelines of successful joint making are followed. Excessive joint clearance can cause the filler metal to crack under stress or vibration. The joint is now ready for soldering. Joints prepared and ready for soldering should be completed the same day and not left unfinished overnight Heating. Because an open flame may be used for soldering, and because flammable gases are used, safety precautions must be observed. The heat is generally applied using an air/fuel torch. Such torches use acetylene or an LP gas. Electric resistance tools can also be used. Heating should begin with the flame perpendicular to the tube. The copper tube conducts the initial heat into the fitting socket for even distribution of heat inside and out. The extent of this preheating depends upon the size of the joint. Experience will indicate the amount of time needed. The flame should now be moved onto the fitting. Then move the flame from the 2015 MINNESOTA PLUMBING CODE 223

4 fitting socket back onto the tube a distance equal to the depth of the fitting socket. Touch the solder to the joint. If the solder does not melt, remove it and continue the heating process. Be careful not to overheat or to direct the flame into the fitting cup. This could cause the flux to burn and destroy its effectiveness. When the melting temperature of the solder has been reached, heat may be applied to the base of the cup to aid capillary action in drawing the solder into the cup Applying the Filler Metal. For tube in a horizontal position, start applying the solder slightly off-center at the bottom of the joint. Proceed across the bottom of the fitting and up to the top center position. Return to the point of beginning, overlap the starting point, and then proceed up the incompleted side to the top, again, overlapping the solder. For joints in the vertical position, a similar sequence of overlapping passes should be made, starting wherever is convenient. Molten solder will be drawn into the joint by capillary action regardless of whether the solder is being fed upward, downward, or horizontally Cooling and Cleaning. After the joint has been completed, natural cooling is best. Shock cooling with water may cause unnecessary stress on the joint and result in eventual failure. When cool, clean off any remaining flux with a wet rag Brazed Joints. Brazing is the second most commonly used method for joining copper tube. Making brazed joints is similar to making soldered joints with respect to measuring, cutting, reaming, cleaning, assembly and support. And as in soldering, the brazing filler metal is melted by the heat of the tube and fitting and drawn into the joint by capillary action. [UPC ] The major differences between soldering and brazing are the: Type of flux used, Composition of filler metal, and Amount of heat required to melt the filler metal Brazing Flux. The fluxes used for brazing copper joints are different in composition from soldering fluxes. The two types cannot be used interchangeably. Brazing fluxes are water based, whereas most soldering fluxes are petroleum based. Similar to soldering fluxes, brazing fluxes dissolve and remove residual oxide from the metal surface, protect the metal from reoxidation during heating and promote wetting of the surfaces to be joined by the brazing filler metal. Fluxes also provide the draftsman with an indication of temperature. Application of the flux is the same as when soldering. If the outside of the fitting and the heat-affected area of the tube are covered with flux (in addition to the end of the tube and the cup), oxidation will be prevented and the appearance of the joint will be greatly improved Brazing Filler Metals. There are two general types of brazing filler metal used for joining copper tube. Classified according to their components, they are: BCuP (Brazing-Copper- Phosphorous) and BAg (Brazing-Silver). BCuP filler metals are preferred for joining copper tube and fittings. The phosphorous in them acts as a fluxing agent and the lower percentage of silver makes them relatively low cost. When using copper tube, wrought copper fittings, and BCuP brazing filler metal, fluxing is optional. However, when cast fittings are brazed, flux must be used Heating. Oxy/fuel torches are generally used for brazing because of the higher temperatures required. Recent innovations in tip design make air/fuel torches useful on a wider range of sizes for brazing. When working at brazing temperatures, safety precautions must be followed and care taken to protect both the operator and the materials being used. The heating operation is the same as for soldering. First preheat the tube and then the tube and fitting. When the filler metal starts to melt, apply heat at the base of the fitting socket to help draw the brazing filler metal in by capillary action Applying Brazing Filler Metal. Remember to allow the heat of the joint, not the flame, to melt the filler metal. The melted filler metal will be drawn into the joint by capillary action. It is very important that the flame be in continuous motion. It must not be allowed to remain on any one point long enough to burn through the tube or fitting. If the filler metal fails to flow, or has the tendency to ball-up, it indicates either that there is oxide on the surfaces being joined or that the parts to be joined are not hot enough. If the filler metal refuses to enter the joint, the fitting cup is not hot enough. If it tends to flow over the outside of either part of the joint it indicates that part is overheated. When the joint is completed, a continuous fillet should be visible completely around the joint. Large diameter tube is more difficult to heat to the desired temperature. The use of a heating MINNESOTA PLUMBING CODE

5 tip or rosebud may be necessary to maintain the proper temperature over the area being brazed. Once total heat control is attained, follow the same procedures used for smaller tube Cooling and Cleaning. When the brazed joint is finished, allow it to cool naturally. Flux residues and some oxides formed by heating can be removed by washing with hot water and brushing with a stainless steel wire brush Flared Joints Flared Joints with Impact Flaring Tools: Step 1 Cut the tube to the required length. Step 2 Remove all burrs. This is very important to assure metal-tometal contact. Step 3 Slip the coupling nut over the end of the tube. Step 4 Insert flaring tool into the tube end. Step 5 Drive the flaring tool by hammer strokes, expanding the end of the tube to the desired flare. This requires a few moderately light strokes. Step 6 Assemble the joint by placing the fitting squarely against the flare. Engage the coupling nut with the fitting threads. Tighten with two wrenches, one on the nut and one on the fitting. [UPC ] Flared Joints with Screw-Type Flaring Tools: Steps 1-3 Same as for impact flaring previously described. Step 4 Clamp the tube in the flaring block so that the end of the tube is slightly above the face of the block. Step 5 Place the yoke of the flaring tool on the block so that the beveled end of the compressor cone is over the tube end. Step 6 Turn the compressor screw down firmly, forming the flare between the chamber in the flaring block and the beveled compressor cone. Step 7 Remove the flaring tool. The joint can now be assembled as in Step 6 for impact flaring. [UPC ] 2.4 Sizing Velocity. Note: There are various hydraulic formulas for the flow of water in pipe. With high velocity and attendant turbulent flow, there can be excessive noise and piping wear. The designer should aim for maximum flow velocities in the range of 5 to 8 feet per second ( meters per second) to minimize noise and erosion problems. For the smallest tube sizes, the designer is wise to work at the bottom of this range, as a maximum, to guard against local high velocities building up due to faulty workmanship (e.g. burrs at tube ends which are not properly reamed) or unusually numerous changes in flow direction. 3.0 General Information. 3.1 It is not possible to cover all the variables of a plumbing system; however, the following information may prove helpful: 3.2 Expansion Loops Copper tube, like all piping materials, expands and contracts with temperature changes. Therefore, in a copper tube system subjected to excessive temperature changes, the line tends to buckle or bend when it expands unless compensation is built into the system. Severe stresses on the joints may also occur. Such stresses, buckles, or bends are prevented by the use of expansion joints or by installing offsets, U bends, coil loops, or similar arrangements in the tube assembly. These specially shaped tube segments take up expansion and contraction without excessive stress. The expansion of a length of copper tube may be calculated from the formula: Temperature Rise ( F) x length (feet) x 12 (inches per foot) x Expansion Coefficient (inch per inch per F) = Expansion (inches), or Temperature Rise ( C) x Length (meter) x 1000 (mm per meter) x Expansion Coefficient (mm per mm per C) = Expansion (mm). Calculations for expansion and contraction should be based on the average coefficient of expansion of copper which is per degree F (1.692 x 10-5 per degree C), between 70 F and 212 F (21 C and 100 C). For example, the expansion of each 100 feet (30.5 meters) of length of any size tube heated from room temperature (70 F) to 170 F (a 100 F (55.6 C) rise) is inches (28.7 mm) MINNESOTA PLUMBING CODE 225

6 100 F x 100 feet x 12 inch/foot x inch/inch/ F = inch, or 55.6 C x mm x 1000 mm/m x x 10-5 mm/mm/ C = 28.7 mm 3.3 Tube Supports See Section and Table of the Uniform Plumbing Code. 3.4 Bending Copper tube, properly bent, will not collapse on the outside of the bend and will not buckle on the inside of the bend. Tests demonstrate that the bursting strength of a bent copper tube can be greater than it was before bending. Because copper is readily formed, expansion loops and other bends necessary in an assembly are quickly and simply made if the proper method and equipment are used. Simple hand tools employing mandrels, dies, forms, and fillers, or power-operated bending machines, are used Both annealed tube and bending-temper tube can be bent with hand benders. The proper size bender for each size tube must be used. Usually the size of the tool corresponds to the nominal outside diameter of the tube, not the standard tube size. For a guide to the typical bend radii, see the following bending guide for copper tube. ADOPTED: 1980 REVISED: 1989, 2003, 2006 BENDING GUIDE FOR COPPER TUBE Tube Size MINIMUM BEND RADIUS In. (mm) TUBE TYPE TEMPER In. (mm) TYPE OF BENDING EQUIPMENT 1 4 (6.4) K, L Annealed 3 4 (19.1) Lever type 3 8 (9.5) 1 2 (12.7) K, L Annealed (38) Lever or gear type 3 (76) None; by hand* K, L, M Drawn (45) Gear Type K, L Annealed (57) Lever or gear type (114) None; by hand* K, L, M Drawn (64) Gear type 3 4 (19.1) 1 (25.4) K, L K L K K, L Annealed Drawn 3 4 K, L Annealed (76) (114) (152) (76) (102) (102) (191) Lever of gear type None; by hand* None; by hand* Gear type Heavy-duty gear type Gear type None; by hand* (31.8) K, L Annealed 9 (229) None; by hand* * When bending by hand, without the use of bending equipment, a circular wooden disc is used. The radius of the disc should be about 1 4 to 1 2 inch (6.4 to 12.7 mm) less than the minimum bend radius shown MINNESOTA PLUMBING CODE

INTRODUCTION. Tube and fitting

INTRODUCTION. Tube and fitting Service Application Manual SAM Chapter 630-41A Section 21 SOLDERING & BRAZING COPPER TUBE The Copper Development Association Inc. INTRODUCTION The material that follows is adapted from publications first