How should sealed-end welding be specified for industrial heating elements?

Specify sealed-end welding from the actual duty first: medium, pressure, thermal cycling and corrosion severity determine the end geometry, filler material and process, whether TIG, brazing or laser. The purchase document should state sheath diameter, wall thickness, material, wattage, surface load, IP rating, mounting and thermostat arrangement, plus the basis for joint tightness. Acceptance can be tiered by risk: visual, dimensional and insulation-resistance checks for standard service; leak, hydrostatic, helium or NDT testing where corrosion or high cycling demands it.