Patent ID: 8728324

Claim:
A method of controlling deposit formation on the structural parts of a steam generating system exposed to an aqueous medium under steam generating conditions, said steam generating system operating under a pressure of 600 psig and greater, said method comprising adding to said aqueous medium an effective amount of a terpolymer having the structure wherein E is the repeat unit remaining after polymerization of an ethylenically unsaturated with compound; R 1 is H or C 1 -C 4 alkyl; R 2 is ethylene, isopropylene, or propylene; f is an integer of 1-100; A is OSO 3 or SO 3 ; G is selected from H or a cation including Na, K, or NH 4 ; R 3 is H or C 1 -C 4 with alkyl; and R 4 is a hydroxyl substituted alkylene radical having from 1 to about 6 carbon atoms; c, d, and e are each a positive integer, and wherein X is OSO 3 or SO 3 and Z is Na, K, NH 4 or H.