Excavating a Bell Hole for 24-inch Pipe Installation
Bell or coupling holes must be excavated so that the bells or
couplings support no part of the load. The pipe barrel is designed
to support the trench load and must rest firmly and evenly on the
trench bottom or bedding material.
Bell or coupling holes must be excavated to prevent point loading of the bells or couplings of laid pipe, and to establish full-length support of the pipe barrel.
When properly installed, there should be room to slide a hand
around the lower half of the bell or coupling before the next pipe is
installed.
Pipe resting on the bells or couplings will likely result in pipe failure.