Cadweld Exothermic Welded C.P. Cable Connections by Erico

Permanent, Welded Connections

CADWELD connections are made with a semi-permanent graphite mold, which holds the conductors to be welded. Weld metal (a mixture of copper oxide and aluminum) is loaded into the top of the mold. The mold is covered and the weld metal ignited. The exothermic reaction produces molten copper, which produces a permanent, high conductivity connection.

Cathodic Protection Connections

• CADWELD connections are the accepted method of attaching cathodic protection cables to pipes (steel or cast iron), tanks and many other steel structures structures.
• CADWELD connections weld conductors to the object to be protected. Therefore, no galvanic corrosion can occur at the interface. With mechanical connections, surface contacts are present, which can corrode, resulting in an ineffective connection and current path.
• CADWELD connections for cathodic protection use a special alloy to provide minimum heat effect on the steel, especially important on thin wall, high stress pipes.
• CADWELD connections are also used for header cable taps, conductor splices and terminations, and ground rod connections. 

A CADWELD Connection...

• Has current carrying capacity equal to that of the conductor.
• Is permanent aand cannot loosen or corrode to cause a high resistance connection.
• Uses lightweight, inexpensive equipment.
• Requires no external source of power or heat.
• Requires no special skills.
• Can be easily checked for quality.

CADWELD Welders and Molds

When making a CADWELD connection, an accurate control of the CADWELD process is accomplished by using a semi-permanent graphite mold. With the mold, control is exercised over the direction and speed of the molten CADWELD weld metal flow and final shape. The graphite used in a CADWELD mold is a high temperature type that lasts for an average of 50 to 100 CADWELD connections under normal usage.

Welder Price Key "CAA" is a solid graphite block with a hold-down handle used for horizontal welding. If a mold only is needed, (without handle), add an "M" to the end of the part number.  Example:  CAHAA-1G-M

Welder Price Keys CAT, CAP and CAN are split molds and use the Mini E-Z handle. All welders uder these price keys includes the handle or "mold frame".

Refer to the "Welder Price" column on the charts in the "Welder" tab on this page.

When making a CADWELD connection, be sure to use all proper PPE including eye protection, gloves and proper clothing.  The CADWELD process is a "hot process" utilzing a molten compound and safety precautions are very important.

CADWELD Exothermic Welding Manual

EFFECTIVE AUGUST 1, 2018, THE MODEL T320 FLINT IGNITOR IS SOLD SEPARATELY AND WILL NOT BE INCLUDED WITH ANY CADWELD WELDER OR MOLD.

Welder Types 

The following Cadweld "welders" are designed to make cable connections to steel pipe or other steel structures.  Each welder is designed to work with a specific cable and pipe size in a horizontal or vertical position.

Type CAHA for Steel Tap conductor (lead wire) to top of horizontal steel pipe or flat surface.

Type CAHC for Steel Through conductor to top of horizontal steel pipe or flat surface.

Type CAVS for Steel Tap conductor to vertical steel pipe or flat surface.

Type CAHB for Cast Iron Tap conductor to top of horizontal cast iron pipe or flat surface.

Type CAHE for Cast Iron Through conductor to top of horizontal cast iron pipe or flat surface.

Type CAVH for Cast Iron Tap conductor to vertical horizontal cast iron pipe or flat surface.

Conductor Size Surface Welder Part No. Welder Price Weld Metal #14-10 solid, or #8 solid or stranded, or #6 solid Flat (30" & larger pipe) 4" to 24" pipe CAVHT-1G CAVHT-1G-P.S. CAT CA25XF-19 6 Stranded Flat (30" & larger pipe) 4" to 24" pipe CAVHT-1H CAVHT-1H-P.S. CAT CA25XF-19 4 Solid Flat (30" & larger pipe) 4" to 24" pipe CAVHT-1K CAVHT-1K-P.S. CAT CA32XF-19 4 Stranded Flat (30" & larger pipe) 4" to 24" pipe CAVHT-1L CAVHT-1L-P.S. CAT CA32XF-19 2 Solid Flat (30" & larger pipe) 4" to 24" pipe CAVHT-1T CAVHT-1T-P.S. CAP CA45XF-19 2 Stranded Flat (30" & larger pipe) 4" to 24" pipe CAVHT-1V CAVHT-1V-P.S. CAP CA45XF-19 1 Stranded Flat (36" & larger pipe) 4" to 30" pipe CAVHT-1Y CAVHT-1Y-P.S. CAP CA65XF-19

CADWELD Weld Metal

CADWELD weld metal is a mixture of copper oxide and aluminum, packaged by size in plastic tubes. Each tube contains the starting powder at the bottom of the plastic tube, with the weld metal on top. These containers are packaged, with metal disks, in polyethylene boxes. The welding metal cannot ignite spontaneously. They can be handled and stored without danger and can be shipped with no special packaging or marking.

Two types of CADWELD weld metal are used for cathodic protection connections:

1. F-33 alloy is used for all connections of cable to cable and cable to steel or stainless steel pipe. The F-33 weld metal containers have green caps.
2. XF-19 alloy is used for all connections to cast iron. XF-19 weld metal containers have orange caps.

 

Size	Packed per
	Box	Std. Pkg.
CA15	20	100
CA25	20	100
CA32	20	100
CA45	20	100
CA65	20	100

Ductile Iron Connections

Tests by ERICO, Inc. indicate that connections to ductile iron pipe can be made using the CADWELD molds and weld metal designated to be used on steel pipe. However, some reports from the field suggest that all ductile iron is not the same. In some cases, the material for steel will not work. In such cases, the molds and weld material for cast iron do work.

We therefore suggest:

1. Whenever possible, make tests on the ductile iron pipe being used to determine if the material for steel can be used.
2. Or use the material (XF-19 alloy) for cast iron. It will make satisfactory connections on all ductile iron.

CADWELD Tools and Accessories

SHIM STOCK CAB-140-A Shim Stock is useful to adapt the conductor when a variety of sizes exist and only a few connections of each one are required.

Technical Information

Piping Code

CADWELD CONNECTIONS TO PIPELINES

1. The American Society of Mechanical Engineers* (ASME) publishes codes relating to the design and installation of pressure piping systems:

1.1. ANSI/ASME B31.8- 2000, GAS TRANSMISSION AND DISTRIBUTION PIPING SYSTEMS.

1.2. ANSI/ASME B31.4- 1998, LIQUID TRANSPORTATION SYSTEMS FOR HYDROCARBONS, LIQUID PETROLEUM GAS, ANHYDROUS AMMONIA, AND ALCOHOLS.

2. In both, under Corrosion Control, the standard allows the attachment of electrical leads using exothermic welding but limits the size of the weld metal used to:

2.1. CA15 for steel pipe.

2.2. CA32XF19 for cast, wrought and ductile iron pipe.

3. These restrictions allow for the welding of #4 AWG and smaller wire to steel pipe using Cadweld Cathodic Type CAHA connections and #6 AWG and smaller to cast, wrought, and ductile iron using Type CAHB connections.

When larger sized conductors must be attached to pressure piping systems covered by these codes, several alternative solutions are available:

3.1. Using a Formed Terminal Bond (page 10), a #2 AWG can be welded to cast, wrought and ductile iron with a CA32XF19.

3.2. Using a Cadweld Bonding Strap (page 8), a 1/6” x 1” copper strip (equivalent to slightly smaller than a #1 AWG) can be welded to a cast, wrought and ductile iron pipe with a CA32XF19.

3.3. The “Punched Strap” Bond (page 9) (1/16” x 1-1/4” copper, equivalent to slightly less than a 1/0 AWG) can be welded to steel pipe using a CA15. The 5-hole model is used for “Dresser Type” couplings and the 2-hole model for standard joints.

3.4. The strands of a larger 7 strand conductor can be spread and each strand welded separately (figure 1) as noted in the following table:

* Available from: The American Society of Mechanical Engineers

CADWELD CONNECTIONS AND PIPE WALL THICKNESS

The following is a discussion of the minimum pipe size required for safe installation of Cadweld Cathodic Connections considering of the service conditions and without special factory testing. Several things must be considered as outlined below.

For a particular wall thickness:

a. The hoop stress in the pipe will increase as the pipe diameter increases.

b. The heat dissipation will be affected by the thermal characteristics of the material in the pipe.

c. The heat dissipation will be affected by the rate of flow of the material through the pipe while making the weld.

d. The pipe strength will be affected by the temperature of the pipe (material temperature).

e. Any internal coating of the pipe must be checked to find if the temperature of the pipe directly under the weld will adversely affect it.

Based on a minimum wall thickness of 0.109 inches* (2.769 mm) and using a CA15 Weld Metal (the maximum allowed to oil or gas piping systems per ANSI/ASME B31.4 and B31.8), the minimum recommended pipe size and schedule is:

Tests made by operating gas companies indicate no damage to a 4” Grade 52 pipe having a 0.109” wall when making a weld to the pipe at 500 psig using a CA15. Welds made to a steel plate 0.109” thick had a maximum copper penetration depth of less than 0.010”. Other tests on tubes with a 0.125” or 0.150” wall showed a copper penetration of 0.005’ maximum.

DUCTILE IRON

Tests by nVent indicate that connections to DUCTILE IRON pipe can be made using the Cadweld molds and weld metal designated to be used on steel pipe. However, some reports from the field suggest that all ductile iron is not the same. In some cases the material for steel will not work. In such cases, the molds and weld material for cast iron do work.

We therefore, suggest:

1. Whenever possible, make tests on the ductile iron pipe being used to determine if the material for steel can be used.

-OR-

2. Use the material for cast iron. It will make satisfactory connections on all ductile iron.