igniter

This point will vary with different methods of ignition, as well as the location of the spark-plug or igniter.

N is pipe from pump E leading to reservoir P. Q is igniter tube.

In any case, always take pains to force out any possible gas before snapping igniter to see if the spark works all right.

If the explosions still continue, conclude that the igniter spark is too weak, or does not take place.