Braze brass barb fittings into brass housing

The customer currently outsources the process to braze brass fittings into the brass housing.  The cost of this outside processing is $30 per part.  By in-sourcing, the part cost will be reduced, and the customer can also avoid delays in the outsourcing process.

Equipment

Ultraheat UPT-S2 Power Supply
HS-4 Heat Station

Materials
• Silver brazing preform.
• Stay-Silv brazing flux

Key Parameters
Temperature: approximately 677°C
Power: 1.98 kW
Time: 150 seconds

Frequency
71 kHz

Process:

1. Braze Brass Fittings into Brass Housing: the barb fittings are positioned into the housing, with a pre-form placed at the position of the joint.
2. The assembly is then positioned into the induction coil.
3. At approximately 2:15, a small amount of brazing alloy is added by hand during the heating, to fill the opening not covered by the preform.  A production preform would completely encircle the part, and not have a gap.
4. The finished braze, shows a consistent fillet at the braze joint.

Results/Benefits:

Enables in-sourcing of an assembly process that has been done by a supplier.  Avoids costly delays in processing.

• Precise control of the time and temperature
• Power on demand with rapid heat cycles
• Repeatable process, not operator dependent
• Safe heating with no open flames
• Energy efficient heating

Pictures

Braze Brass Fittings into a Brass Housing: the barb fittings are positioned into the housing, with a preform placed at the position of the joint.  The assembly is then positioned into the induction coil.

After approximately 30 seconds.

After approximately 1 minute.

After approximately 90 seconds.

After approximately 2 minutes.  We see a small gap not covered by the preform.

After approximately 2:15.  A small amount of brazing alloy is added by hand during the heating, to fill the small gap not covered by the preform.

The finished braze after 2:30, shows a consistent fillet at the braze joint.

Videos

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Brazing a Heat Exchanger

The customer’s application is Brazing a Heat Exchanger.  There are “U” returns that are brazed to the receiving tubes on the heat exchanger.  These returns are used to flow the water through the heat exchanger, and keep the unit cooled.  Brazing tests were conducted with flux and without flux at the customer’s request.  The current process is done with a torch.

EquipmentUltraheat UPT-S5 Power Supply
HS-4 Heat Station

Materials
• Brazing preform
• Brazing flux (Test 1 only)

Key Parameters
Key Parameters
Temperature: approximately 1400-1450°F
Power: 2.35 kW
Time: 35 seconds for the first part. Slightly less time for subsequent parts, as heat is retained.

Frequency
145 kHz

Process:

1. For Test 1, we pre-coated the U return braze ring and receiving tube with white braze flux; then assembled the heat exchange unit with 13 U returns. (One set of tubes was left open for the customer to pressure test the assembly).  For Test 2, the unit was assembled without flux.
2. By moving the coil and heat station up/down, the assembly was moved in position to braze the components together.
3. We placed a copper shield “comb” under four receiving tubes to shield the plated carbon steel plate from the RF Field and heated the section to flow the phosphor bronze alloy pre-formed rings to braze on both sides of the U-bend simultaneously.
4. Heat time for the initial braze was recorded at 35 seconds – subsequent brazes required less time as the unit retains some heat following each cycle.

Results/Benefits:

Enables in-sourcing of an assembly process that has been done by a supplier.  Avoids costly delays in processing.

• Precise control of the time and temperature
• Power on demand with rapid heat cycles
• Repeatable process, not operator dependent
• Safe heating with no open flames
• Energy efficient heating

Pictures

Brazing a Heat Exchanger.  Test 1 (with flux): Flux is applied to the Heat Exchanger receiving tubes.

Brazing a Heat Exchanger.  Test 1 (with flux): Flux is applied to the "U"-shaped returns.

Brazing a Heat Exchanger.  Test 1 (with flux): "U"-shaped returns are assembled to the receiving tubes.

Brazing a Heat Exchanger.  Test 1 (with flux): A protective shield was placed around the area to be brazed.  This rudimentary shield provided some protection to the plate.  In a final production unit, the plate will be water-cooled.

Brazing a Heat Exchanger.  Test 1 (with flux): We braze each shaped return.  Brazing takes approximately 35 seconds per return.

Brazing a Heat Exchanger.  Test 1 (with flux): A completed braze.

Brazing a Heat Exchanger.  Test 1 (with flux): A completed braze.

Brazing a Heat Exchanger.  Test 2 (without flux): The customer also requested brazing samples without flux.

Brazing a Heat Exchanger.  Test 2 (without flux): Some completed and in-process brazes.

Brazing a Heat Exchanger.  Test 2 (without flux): The final braze on the heat exchanger is started.

Pictures

Brazing without flux:

Brazing with flux:

Induction Heating Mesh Tube for Plasma Research

To generate plasma, we apply an electrical field to a gas, with the goal of removing electrons from their nuclei.  These free-flowing electrons give the plasma key properties, including its electrical conductivity, a magnetic field, and sensitivity to external electromagnetic fields.

In this application test, the customer provided sample parts to be induction heated.  Ultraflex demonstrated the ability of the UPT-S5 5 kW Induction system to heat the stainless steel mesh tube to 1700⁰F within one minute.  The test of Induction Heating Mesh Tube for Plasma Research validated the use of this system for the customer.  

Mesh Tube tested with UPT-S5 Induction Heating System for Plasma Research.

Equipment

Ultraheat UPT-S5 Power Supply
HS-4 Heat Station

Materials
• Stainless Steel Mesh tube 2.2” OD, 0.020” wall thickness

Key ParametersTemperature: 1700⁰F
Power: 2.8 kW
Time: 39 seconds
Frequency: 65 kHz

Process:

1. The stainless steel mesh tube was centered in the coil and painted with 1500⁰F and 1700⁰F tempilaq indication paint.
2. The UPT-S5 was turned on, and a length of 4” was heated to over 1700⁰F in 38 seconds. By successfully Induction Heating mesh tube for Plasma Research, the customer was satisfied that the UPT-S5 would meet his requirements.

Results/Benefits:

• Precise control of the time and temperature
• Power on demand with rapid heat cycles
• Repeatable process, not operator dependent
• Safe heating with no open flames
• Energy efficient heating

Pictures

Mesh Tube used for Heating

Induction Heating SS Tube for Plasma Research

To generate plasma, we apply an electrical field to a gas, with the goal of removing electrons from their nuclei.  These free-flowing electrons give the plasma key properties, including its electrical conductivity, a magnetic field, and sensitivity to external electromagnetic fields.

In this application test, the customer provided sample parts to be induction heated.  Ultraflex demonstrated the ability of the UPT-S5 kW Induction system to heat the stainless steel tube to 1700⁰F within one minute.  This successful application test for Induction Heating SS Tube for Plasma Research, validated the customer’s use of the system for his testing.

EquipmentUltraheat UPT-S5 Power Supply
HS-4 Heat Station

Materials
• Stainless Steel tube 2” nominal OD 0.047” wall thickness

Key ParametersTemperature: 1700⁰F
Power: 4.2 kW
Time: 60 seconds
Frequency: 65 kHz

Process:

1. The stainless steel tube was centered in the coil and painted with 1500⁰F and 1700⁰F tempilaq indication paint.
2. The heat time for the UPT-S5 was set for 60 seconds.
3. A 5” length heated above 1500⁰F; and a 4” length heated over 1700⁰ This met the customer’s requirements for Induction Heating SS Tube for Plasma Research.
4. Uniform heat can be achieved by profiling the coil turns.

Results/Benefits:

• Precise control of the time and temperature
• Power on demand with rapid heat cycles
• Repeatable process, not operator dependent
• Safe heating with no open flames
• Energy efficient heating

Pictures