Overview

The following application solutions need to be considered carefully in respect of the material being welded, the weld process and the weld prep geometry all have a bearing on the choice of Zeromag components and application.  A Zeromag options sheet outlines the techniques and choices available.  For pipe welders we have put together a package of items in our “demagnetizers kit for pipe welders” DKPW that addresses most pipe butt weld applications.

Active nulling:

This is the patented Zeromag technique used to zero the magnetic field in the weld prep.  This field is actively measured and Zeromag ZM100A dynamically controls the demagnetizing current to keep the magnetic field in the weld prep zero even if the remenant field changes in magnitude and polarity.

Joint degauss:

The ZM150 and Zeromag can be used to degauss the complete joint before welding.  This can be very effective in production scenarios but its success does depend on good demagnetizing coil coupling to the pipe, pipe size, wall thickness and the pipe material.  In most pipe lay applications the degaussing coils would be applied using ZMCC clam coils.

Pipe end degauss:

Using the pipe end degauss unit ZM150 with Zeromag allows magnetism to be removed from the pipe ends before fit up.  Although the magnetism will return slowly over time, this technique can be built into the production process to allow welders to work with effectively zero field pipes.  The demagnetizing coils for this application are supplied on bobbins.

Large diameter & plate working:

In weld scenarios where the objects are large plates or large diameter pipes, it is not possible to wind coils around the components.  To overcome this, Diverse supply ZeroZone, this very effectively couples magnetic field into the weld preparation region allowing effective nulling.  Typical applications are ship building, PNG (pressurized natural gas) tanks and steel structures within aluminium smelters.

High power units:

The ZM100A is able to provide up to 1.5KW of demagnetizing power into the coils.  Although sufficient for most applications there are weld scenarios where the power is insufficient, such as joint degaussing on larger diameter pipes, smelting works and objects where it is difficult to get sufficient turns for the demagnetizing coils.  The ZM100A-33 can supply a full 3KW to the coils