letters patent of removable full automatic and unmanned comparment heat exchang station

letters patent of air cooler shutter blade punching cut die

letters patent of vertical floating head heat exchanger

letters patent of unequal cross-sectional flow area plate heat exchager

untility model patent certificate of spiral corrugated plate heat exchanger

letters patent of spray type slag water heat exchanger

letters patent of flat-cover sealed removable spiral plate heat exchanger

letters patent of fully welded wide-channel plate heat exchanger

letters patent of heater for hot mixing heat supply network

letters patent of heater for hot mixing heat supply network

letters patent of heater for hot mixing heat supply network

untility model patent certificate of heat exchanger plates with different corrugated shapes