I guess what post from "lionnoisy" meant was that tanks such as
M1A1/2s, Merkavas etc are designed with blow off panels in the main
round storage compartments in the turret bustle. When the armor is
penetrated where the main round in the turret is located, any
explosion ( or pressure increase ) will vent off safely. Note that
Western tank rounds are sometimes individually encased in
protective jackets ( eg with water in case of Merkava ). The
propellants in the round also do not explode so easily unlike
Russian rounds.
When penetrated , Russian tanks usually blow up from the secondary
explosions from the main rounds. Western tanks are much more
survivable.