We provide the operator with a rash of closed weld heads, which are the slimmest weld heads in their area of application in orbital welding worldwide. The unique clamping system made of spring steel (CWH 21 & CWH 38) enables the operator a comfortable usage, it is inexpensive and can be readjusted several times. Additionally the CWH 21 is able to be reconstructed into a scroll block with a clamping block. The components which have to be welded, are positioned into the clamping block, clamped and this block is put into the weld head. The operator saves the sewing-process and can weld the components in a centered way together. The bigger, water cooled weld heads CWH 53, CWH 76 and CWH 115 are equipped with springing clamping jaws, which are secured by utility patent.