Complex sentence: This water fills the cavity C on the other side of the diaphragm so that pressure is equal on both sides of the diaphragm, however the compressed spring supplies a net downward force.
Split into simpler sentences: This water fills the cavity C on the other side of the diaphragm so that pressure is equal on both sides of the diaphragm. The pressure is the same on both sides of the diaphragm however the compressed spring supplies a net downward force.