BRAZING AND SOLDERING Turn to the SERVICEMAN’S GUIDE Pros
BRAZING WORKSHOP Individuals who desire further training in correct soldering, brazing, and welding procedures should consider attending The Harris Products Group’s brazing workshop. This two-day, comprehensive course, conducted by The Harris Products Group’s Technical Staff, covers fundamentals of torch brazing. The course combines classroom discussion with hands-on metal joining experience including basic metallurgy, base metals, filler metals, equipment, technique, and safety.
CONTENTS PROCEDURES AND TECHNICAL INFORMATION Procedures for Brazing Pipe and Tubing Procedures for Troubleshooting Brazing Pipe and Tubing 6-11 12-13 PRODUCTS AND SPECIFICATIONS TM 16-17 18-19 20 21 22 23 24-25 27 28 29 30 36-37 TM 17 19 20 23 27 28 28 28 29 29 29 30 32-33 32-33 34-35 37 Ring of Fire Stay-Brite® Silver-bearing Solders Common Lead-Free Solders Bridgit® Lead-Free Solders Safety-Silv® High Silver Brazing Alloys Estimating Brazing Alloy Amounts Stay-Silv® Phos/Copper Brazing Alloy
FOREWORD Brazing is a metal joining process utilizing a filler metal that melts above 840ºF and below the melting point of the base metals. The filler metal is drawn into the joint by capillary attraction producing a sound, leak-proof connection. The above sentences briefly describe a process that is an integral part of manufacturing, installing, and repairing refrigeration and air conditioning systems.
PROCEDURES AND TECHNICAL INFORMATION PH: 513-754-2000 THE HARRIS PRODUCTS GROUP www.harrisproductsgroup.
PROCEDURES FOR BRAZING PIPE AND TUBING CUT TUBE SQUARE. Cut to the exact length required using a tube cutter or hacksaw. If a hacksaw is used, a sawing fixture should also be used to ensure square cuts. Remove all inside and outside burrs with a reamer, file, or other sharp edge scraping tool. If tube is out of round, it should be brought to true dimension and roundness with a sizing tool. CLEAN TUBE END AND INSIDE SURFACE OF FITTING.
PROCEDURES FOR BRAZING PIPE AND TUBING PERFORM PROPER FLUXING Proper fluxing is important because the flux absorbs oxides formed during heating and promotes the flow of the filler metal. When using Stay-Silv® white flux, apply it only with a brush. To prevent excess flux residue inside refrigeration lines, apply a thin layer of flux to only the male tubing. Insert the tube into the fitting and, if possible, rotate the fitting once or twice on the tube to ensure uniform coverage.
PROCEDURES FOR BRAZING PIPE AND TUBING ADJUST TORCH FLAME OXYGEN/ACETYLENE For most brazing jobs using oxy-acetylene gases, a slightly carburizing or neutral flame should be used. The neutral flame has a well defined inner cone. Avoid an oxidizing flame.
PROCEDURES FOR BRAZING PIPE AND TUBING HEATING THE JOINT AREA. Always keep the torch in short motion. Heating 1 2 firstAlloy applying the flame to a point just 1 Start heating the tube, byApply Heating adjacent to the fitting. Work the flame alternately around the tube and fitting until both reach brazing temperature, before applying the brazing filler metal. 1 Heating 2 When a flux is used, it will be a good temperature guide.
PROCEDURES FOR BRAZING PIPE AND TUBING APPLY THE BRAZING ALLOY. Feed the alloy into the joint between the tube and the fitting. Only after the base metals have been heated to brazing temperatures should the filler metal be added. At that time, the flame may be deflected momentarily to the tip of the filler metal to begin the melting process. Always keep both the fitting and the tube heated by playing the flame over the tube and the fitting as the brazing alloy is drawn into the joint.
PROCEDURES FOR BRAZING PIPE AND TUBING NITROGEN PURGE During braze heating, oxide scale forms on the inside of the copper tube. These dark scales flake off and are carried by refrigerant and can potentially clog small orifices. For HVAC/R and medical gas installations flow nitrogen through the tube during brazing to prevent internal scale formation. Use a low flow rate to avoid excess pressure inside the tube. A small hole at the line end will allow the nitrogen to escape.
TROUBLESHOOTING FOR BRAZING PIPE AND TUBING The art of brazing is relatively simple, and the rules of common sense apply. Occasionally, however, things do go wrong, and the brazing process fails to do its job satisfactorily. The check lists below have been prepared to assist in such instances. They are intended to provide practical tips on what to what to look for and steps to correct them.
TROUBLESHOOTING FOR BRAZING PIPE AND TUBING IF THE FILLER METAL CRACKS AFTER IT SOLIDIFIES 1 2 3 4 When brazing dissimilar metals, the different coefficient of expansion may put the filler metal in tension just below the liquidus temperature during cooling. This sometimes occurs in a copper-tosteel joint. The copper expands and contracts at a greater rate than the steel. Brazing alloys are stronger in compression, so a steel-to-copper assembly would help alleviate the problem.
THE HARRIS PRODUCTS GROUP www.harrisproductsgroup.
PRODUCTS & SPECIFICATIONS PH: 513-754-2000 THE HARRIS PRODUCTS GROUP www.harrisproductsgroup.
RING OF FIRE™ STAY-SILV® 15% BRAZING RINGS Convenient | Consistent | Quality Ring of Fire™ is the perfect alternative to any brazing project. It’s easy to use, provides a consistent braze every time and meets the same high standards expected from Harris. THE HARRIS ADVANTAGE: • Made in the USA.
RING OF FIRE™ ORDERING INFORMATION PART # DESCRIPTION SIZE RF15250 SS15 - 1/4” Joint Ring x 25 pkg. 1/4” RF15375 SS15 - 3/8” Joint Ring x 25 pkg. 3/8” RF15500 SS15 - 1/2” Joint Ring x 25 pkg. 1/2” RF15625 SS15 - 5/8” Joint Ring x 25 pkg. 5/8” RF15750 SS15 - 3/4” Joint Ring x 25 pkg. 3/4” RF15875 SS15 - 7/8” Joint Ring x 25 pkg. 7/8” RF15125 SS15 - 1 1/8” Joint Ring x 10 pkg.
STAY-BRITE® SILVER-BEARING SOLDERS Extremely versatile, Stay-Brite® silverbearing solders are widely used throughout the industry as a better-than-brazing method in many situations. Stay-Brite® silver bearing solders were introduced to the air conditioning industry more than 40 years ago. Today, Stay-Brite® is the most used of all solders. The important advantage of Stay-Brite® solders is the greater strength of the overall component.
STAY-BRITE® SILVER-BEARING SOLDERS STAY-BRITE® JOINT vs.
COMMON LEAD-FREE SOLDERS COMMON WIRE SOLDERS FOR TIN-LEAD TIN-LEAD 50/50, 40/60, 60/40 Meets ASTM B32. With some exceptions, the tin-lead solders can be used to solder copper to most copper, lead, high-nickel and steel alloys. Tin-lead solders are not recommended for use in high stress or vibration joints in the cooling industry due to lack of sufficient elongation properties. Heat sources for use with solder include soldering guns, irons, and torch applications. TIN-ANTIMONY 95/5 Meets ASTM B32.
BRIDGIT® LEAD-FREE SOLDER BRIDGIT® A patented, high-performance, lead-free solder developed by The Harris Products Group in response to the Federal ban on the use of lead solders in drinking water systems. This lead-free solder is specially formulated to fill both tight and loose-fitting connections. The nickel content in Bridgit® solder creates joints that are substantially stronger than those joints soldered with 50/50, 95/5 or common lead-free solders.
SAFETY-SILV® HIGH SILVER BRAZING ALLOYS SAFETY-SILV® The Harris Products Group manufactures its complete line of cadmium-free, high silver brazing alloys with the same attention to quality found in their phosphorus / copper products. Only the purest metals are used. Precision production procedures ensure consistency in product quality and performance. Safety-Silv® alloys are strongly recommended as replacements for all cadmium-bearing brazing filler metals.
ESTIMATING BRAZING ALLOY AMOUNTS ESTIMATING AMOUNTS OF BRAZING ALLOYS REQUIRED 1 Locate the tube diameter to be joined and the wire size to be used. Where the row and the column intersect is the approximate length in inches of alloy required per joint. 2 Multiply the length of the alloy needed per joint by the total number of joints. 3 To convert the total length to pounds or troy ounces, divide by the inches of alloy/lb. in row A or the inches of alloy/troy oz. in row B.
STAY-SILV® PHOS-COPPER BRAZING ALLOYS HARRIS® 0 Low-cost alloy for many copper-to-copper applications where good fit-up can be maintained and brazing temperature is not critical. STAY-SILV® 5 AND STAY-SILV® 6 Medium-range alloys, Stay-Silv® 5 is useful primarily where fit-up cannot be tightly controlled. Stay-Silv® 6 is slightly more fluid and can be used where closer tolerances are available. Both alloys are somewhat more ductile than Harris® 0.
STAY-SILV® PHOS-COPPER BRAZING ALLOYS Phos/copper and silver/phos/copper alloys are used to braze copper-to-copper and copper-to-brass. The phosphorus content in these alloys makes them self-fluxing on copper. When brazing brass or copper to brass, use Stay-Silv® white brazing flux. These alloys are not recommended for brazing steel or other ferrous metals.
THE HARRIS PRODUCTS GROUP www.harrisproductsgroup.
ALUMINUM ALLOYS BRAZING AND SOLDERING ALUMINUM Aluminum can be soldered or brazed if the correct procedure is followed. Pre cleaning is essential to break up the tough aluminum oxide film. Thorough brushing with a stainless steel wire brush is recommended. Most common aluminum alloys such as 1100 and 3003 can be readily soldered or brazed. It should be noted that some alloys are difficult to join. Dissimilar metal connections may be subject to galvanic corrosion in certain service conditions.
SAFETY-SILV® HIGH SILVER BRAZING ALLOYS Safety-Silv®56 Safety-Silv®45 (Flux-Coated) Safety-Silv®40 SAFETY-SILV® 56 CHEMICAL COMPOSITION 56 % Ag 22 % Cu 17 % Zn 5% Sn SPECIFICATIONS SOLIDUS LIQUIDUS AWS A5.8 BAg-7 NSF 51 1205°F 652°C 1145°F 618°C TYPICAL APPLICATION For ferrous and nonferrous alloys. Often used to braze stainless steel for use with food equipment materials. SAFETY-SILV® 45 CHEMICAL COMPOSITION 45 % Ag 30 % Cu 25 % Zn SPECIFICATIONS SOLIDUS LIQUIDUS AWS A5.
SOLDERS 50/50 Stay-Brite® 60/40 STAY-BRITE® SOLDERS CHEMICAL COMPOSITION 4 % Ag 96 % Sn SPECIFICATIONS SOLIDUS LIQUIDUS TYPICAL APPLICATION ASTM B32 Sn96 NSF 51 J-STD-006 Sn96 Ag O4A 430°F 221°C Use with all metals except aluminum. Low temperature solder used in HVAC/R industry.
FLUXES FLUXES DESCRIPTION SPECIFICATION ACTIVE TEMP STAY-SILV® WHITE BRAZING FLUX Meets Federal Spec. (OF499,Type B AWS A5.31) Class FB3-A AMS 3410 1050-1600°F (565 - 870° C) Meets Federal Spec. (OF499,Type B AWS A5.31) Class FB3-C AMS 3411 1050 -1700°F (565 - 926°C) Meets Commercial Spec. A-A-51145 Type II Form B 300 - 700°F (148 - 371°C) Meets Commercial Spec.
CHARTS
PHOS-COPPER BRAZING ALLOYS DESCRIPTION CHEMICAL COMPOSITION SPECIFICATIONS STAY-SILV® 15 15% Ag 5% P 80% Cu AWS A5.8 BCuP-5 1 6 5% Ag 6% P 89% Cu AWS A5.8 BCuP-3 1 6 6% Ag 6% P 88% Cu -------- 1 6 7.2% P 92.8% Cu AWS A5.
61 SOLIDUS LIQUIDUS TYPICAL APPLICATION 1190°F 643°C 1475°F 802°C Designed primarily for copper to copper brazing application, it may also be used in brazing brass with the use of Stay-Silv® brazing flux. 1190°F 643°C 1500°F 816°C Well suited where close fit-up cannot necessarily be maintained. 1190°F 643°C 1465°F 796°C5 Designed for copper-to-copper applications, it may also be used on brass. Provides the ability to braze poorly fitted as well as tight connections.
FILLER METALS SELECTION CHART METALS TO BE JOINED SOLDERS BRAZING FILLER METALS Stay-Brite® Stay-Brite® 8 Bridgit ® COPPER OR BRASS TO 430°F / 221°C 430°F / 221°C 460°F / 238°C Blockade® Harris® 0 Stay-Silv® 5 Dynaflow® Stay-Silv® 6 Stay-Silv® 15 COPPER OR BRASS COPPER OR BRASS SOLIDUS 1178°F / 637°C 1310°F / 710°C 1190°F / 643°C 1190°F / 643°C 1190°F / 643°C 1190°F / 643°C 430°F / 221°C 430°F / 221°C Stay-Brite® Stay-Brite® 8 TO Safety-Silv® 56 Safety-Silv® 38T Safety-Silv® 45 Safety-Silv® 45
FLUIDITY RATING* LIQUIDUS 430°F / 221°C 535°F / 279°C 630°F / 332°C 10 8 6 1247°F / 674°C 1475°F / 802°C 1500°F / 816°C 1465°F / 796°C 1425°F / 774°C 1480°F / 804°C 7 5 3 3 5 3 430°F / 221°C 535°F / 279°C 10 8 1205°F / 652°C 1325°F / 718°C 1370°F / 743°C 1265°F / 685°C 8 7 6.5 7 430°F / 221°C 535°F / 279°C 10 8 C C C C C C 1205°F / 652°C 1325°F / 718°C 1435°F / 779°C 1370°F / 743°C 1265°F / 685°C 1305°F / 707°C 8 7 4.5 6.5 7 7 C C 1435°F / 779°C 1305°F / 707°C 4.
HEATING EQUIPMENT HARRIS INFERNO® Harris Inferno® air-fuel equipment allows for soldering and brazing of a variety of tube sizes. Equipment attaches to a B (40 cu. ft.) or MC (10 cu. ft.) acetylene cylinder. The Inferno® tip provides a special swirl combustion approach to increase flame velocity and homogenize the gas mixture. For air-acetylene, fuel gas delivery pressure should be set at 14-15 PSI. When soldering or brazing different size connections, change tip size rather than reducing flow.
HEATING EQUIPMENT HARRIS PORT-A-TORCH® The Harris Port-A-Torch® contains all the quality equipment needed for cutting, welding and brazing packaged in a rugged, molded plastic carrying case. The outfit is designed to carry one MC acetylene cylinder and one 20 cu. ft. oxygen cylinder. As supplied, the outfit is capable of cutting up to a 1” plate and welding up to a 1⁄16”plate . The outfit can cut up to a 4” plate and weld up to a 1⁄2” plate with larger tips and acetylene cylinder.
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PH: 513-754-2000 THE HARRIS PRODUCTS GROUP www.harrisproductsgroup.
The Harris Products Group 4501 Quality Place, Mason, OH 45040-1971 513-754-2000 THE HARRIS PRODUCTS GROUP www.harrisproductsgroup.com PH: 513-754-2000 40www.harrisproductsgroup.