CFR > Title 33 - Navigation and Navigable Waters > CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY > SUBCHAPTER O—POLLUTION (parts 151 to 159) > PART 157—RULES FOR THE PROTECTION OF THE MARINE ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN BULK > SUBPART D—Crude Oil Washing (COW) System on Tank Vessels (§157.100 to §157.172) > 157.112—Approved Crude Oil Washing Operations and Equipment Manual.