In order to minimize weld cost it is often prudent to make several welds with one stroke of the machine. If time is of the essence, this can be done with a dedicated machine design. Multiple cylinders would all operate at nearly the same time. Their timing is usually spaced slightly to reduce power demand. If multiple welds are in a modest space multiple cylinders may not fit. Then specialized multi spot equalizing holders might be the solution.
MULTI SPOT EQUILIZING HOLDERS
Mutispot equalizing holders are designed to hold two or three electrodes and equalize current and pressure between them during the welding operation. Each stroke of the welder two or three equal welds will be made. The holders come in light and heavy duty models. All provide water cooling for the electrodes.
References: RWMA - Resistance Welding Manual 4th Edition
Tuffaloy Resistance Welding Products Catalog