Inhibition of corrosion in return steam condensate lines

Claim 1

A PROCESS OF INHIBITING CORROSION IN STEAM AND CONDENSATE RETURN SYSTEMS IN WHICH THE STEAM AND CONDENSATE ARE CARRIED BY FERROUS METAL PIPES NORMALLY SUSCEPTIBLE TO CORROSION WHICH COMPRISES INTRODUCING INTO SUCH SYSTEMS A CORROSION INHIBITING AMOUNT OF A COMPOUND FROM THE GROUP CONSISTING OF HYDROXYALKYLATED ALKYLENE DIAMINES CONTAINING A SINGLE LONG ALIPHATIC HYDROCARBON CHAIN HAVING FROM 10 TO 32 CARBON ATOMS ATTACHED TO ONE OF THE NITROGEN ATOMS AND HYDROXYALKYLATED WITH FROM 1 TO 4 MOLS OF A LOWER ALKYLENE OXIDE FOR EACH MOL OF SAID DIAMINE TO LINK HYDROXYALKYLENE GROUPS TO AT LEAST ONE OF THE NITROGEN ATOMS TO THE EXTENT THAT AT LEAST 5% BY WEIGHT OF SAID HYDROXYALKYLATED DIAMINE IS WATER DISPERSIBLE AND THE SALTS OF SAID HYDROXYALKYLATED DIAMINES WITH ALIPHATIC CARBOXYLIC ACIDS CONTAINING NOT MORE THAN 10 CARBON ATOMS FROM GROUP CONSISTING OF ALIPHATIC MONOCARBOXYLIC ACIDS, ALIPHATIC DICARBOXYLIC ACIDS HYDROXY ALIPHATIC MONOCARBOXYLIC ACIDS AND HYDROXY ALIPHATIC POLYCARBOXYLIC ACIDS, SAID CARBOXYLIC ACIDS CONTAINING ONLY CARBON,,HYDROGEN AND OXYGEN ATOMS, SAID COMPOUNDS BEING FURTHER CHARACTERIZED BY THE FACT THAT THE INITIAL ALKYLENE DIAMINES PRIOR TO HYDROXYALKYLATION CONTAIN 2 TO 6 CARBON ATOMS CONNECTING THE AMINO NITROGEN ATOMS.