34430 - Fabricated plate work (Boiler shops - Miscellaneous)
34431 - Heat exchangers & Steam condensers, except for Nuclear applications
3443113 - - Heat exchangers, Closed types, Industrial: Bare tube
3443118 - - Heat exchangers, Closed types, Industrial: Fin tube
3443155 - - Heat exchangers, Closed types, Industrial: Steam condensers
3443199 - - Heat exchangers & Steam condensers, except for Nuclear applications (Miscellaneous)
34432 - Fabricated steel plate (Stacks & Weldments) except heat exchangers, Steel power boilers, Gas cylinders, Nuclear reactor, etc.
3443221 - - Shielding for use in nuclear reactors
3443236 - - Pipe, Penstocks, Tunnel lining, Stacks & Breeching
3443244 - - Fabricated steel plate containers (Trash & Other) <13 gal
3443245 - - Trash containers (Steel plate)
3443246 - - Fabricated steel plate containers (Trash & Other) 13 gal to 79 gal
3443247 - - Containers (General - Steel plate)
3443248 - - Fabricated steel plate containers (Trash & Other) >79 gal
3443252 - - Fabricated steel plate sound control equipment for Jet engine test facilites (incl Hush houses, Demountable run-up silencers, Demountable test cells, etc.)
3443254 - - Fabricated steel plate sound control equipment for Gas turbine sound systems (Enclosed, incl Natural gas compression, Electric generation, Marine propulsion, etc.)
3443256 - - Other Fabricated steel plate sound control equipment (incl Sound panels, One piece enclosures, Industrial silencers & Air duct silencers)
3443298 - - Weldments & Fabricated steel plate for other Purposes
3443299 - - Weldments & Fabricated steel plate for other Purposes
34433 - Steel power boilers, Parts & Attachments (>15 p.s.i. steam working pressure) except for Nuclear applications
3443308 - - Water tube steel power boilers (Stationary & Marine) 10000 lb/hr or less 15 p.s.i. steam working pressure or less (except for Nuclear applications)
3443310 - - Water tube steel power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 10000 lb/hr or less, Saturated (except for Nuclear applications)
3443312 - - Stationary power boilers: Water tube: =<10000 lb/hr:>15-449 p.s.i. steam working pressure
3443313 - - Water tube steel power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 10000 lb/hr or less (except for Nuclear applications)
3443314 - - Stationary power boilers: Water tube: =<10000 lb/hr:>450 p.s.i. steam working pressure
3443315 - - Water tube steel power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 10000 lb/hr or less, Super heated (except for Nuclear applications)
3443316 - - Stationary power boilers: Water tube: 10001 lb/hr-100000 lb/hr: >15-449 p.s.i. steam working pressure
3443317 - - Water tube steel power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 10001 lb/hr to 100000 lb/hr (except for Nuclear applications)
3443318 - - Stationary power boilers: Water tube: 10001 lb/hr-100000 lb/hr: =>450 p.s.i. steam working pressure
3443319 - - Water tube steel power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 10001 lb/hr to 100000 lb/hr, Saturated (except for Nuclear applications)
3443321 - - Stationary power boilers: Water tube: 100001 lb/hr-250000 lb/hr: >15-449 p.s.i. steam working pressure
3443322 - - Water tube steel power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 100001 lb/hr to 250000 lb/hr (except for Nuclear applications)
3443323 - - Stationary power boilers: Water tube: 100001 lb/hr-250000 lb/hr: =>450 p.s.i. steam working pressure
3443324 - - Water tube steel power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 10001 lb/hr to 100000 lb/hr, Super heated (except for Nuclear applications)
3443326 - - Water tube steel power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 100001 lb/hr to 250000 lb/hr, Saturated (except for Nuclear applications)
3443328 - - Water tube steel power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 100001 lb/hr to 250000 lb/hr, Super heated (except for Nuclear applications)
3443330 - - Water tube steam power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 250001 lb/hr or more, Saturated (except for Nuclear applications)
3443331 - - Stationary power boilers: Water tube: =>250001 lb/hr: >15-449 p.s.i. steam working pressure
3443332 - - Water tube steam power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 250001 lb/hr or more (except for Nuclear applications)
3443333 - - Stationary power boilers: Water tube: =>250001 lb/hr: =>450 p.s.i. steam working pressure
3443334 - - Water tube steam power boilers (Stationary & Marine) >15 p.s.i. steam working pressure, 250001 lb/hr or more, Super heated (except for Nuclear applications)
3443335 - - Other Water tube steam power boilers (Stationary & Marine) incl 10001 lb/hr or more with 15 p.s.i. steam working pressure or less (except for Nuclear applications)
3443336 - - Stationary power boilers: Fire tube: Horizontal return tubular
3443337 - - Fire tube steam power boilers (Stationary & Marine) Horizontal return tubular, 15 p.s.i. steam working pressure or less (except for Nuclear applications)
3443338 - - Fire tube steam power boilers (Stationary & Marine) Firebox, >15 p.s.i. steam working pressure (except for Nuclear applications)
3443339 - - Vertical fire return tubular type steam power boilers (Stationary & Marine) >15 p.s.i. steam working pressure (except for Nuclear applications)
3443340 - - Fire tube steam power boilers (Stationary & Marine) Horizontal return tubular, >15 p.s.i. steam working pressure (except for Nuclear applications)
3443341 - - Fire tube steam power boilers (Stationary & Marine) Firebox, 15 p.s.i. steam working pressure or less (except for Nuclear applications)
3443342 - - Stationary power boilers: Scotch type: Steam pressure type
3443343 - - Stationary power boilers: Scotch type: Hot water type
3443344 - - Fire tube steam power boilers (Stationary & Marine) Firebox, >15 p.s.i. steam working pressure (except for Nuclear applications)
3443345 - - Stationary power boilers: other Types
3443346 - - Fire tube steam power boilers (Stationary & Marine) Scotch type pressure, 15 p.s.i. steam working pressure or less (except for Nuclear applications)
3443347 - - Fire tube steam power boilers (Stationary & Marine) Scotch type pressure, >15 p.s.i. steam working pressure (except for Nuclear applications)
3443348 - - Marine boilers
3443349 - - Super heated water steel power boilers, Stationary & Marine (except for Nuclear applications)
3443350 - - Other Steel power boilers, Stationary & Marine (except for Nuclear applications)
3443351 - - Other Steel power boilers, Stationary & Marine (except for Nuclear applications)
3443352 - - Parts & Attachments for Steel power boilers
3443399 - - Steel power boilers, Parts & Attachments (>15 p.s.i. steam working pressure) except for Nuclear applications
34434 - Gas cylinders
3443412 - - Gas cylinders: Ferrous
3443413 - - Seamless ferrous gas cylinders
3443414 - - Seamless ferrous & Nonferrous gas cylinders
3443415 - - Seamless nonferrous gas cylinders
3443416 - - Welded ferrous & Nonferrous gas cylinders
3443417 - - Welded ferrous gas cylinders
3443418 - - Gas cylinders: Nonferrous
3443419 - - Welded nonferrous gas cylinders
3443499 - - Gas cylinders (Miscellaneous)
34435 - Metal tanks, Complete (Standard line pressure)
3443520 - - Liquefied petroleum gas tanks (All types)
3443521 - - Liquefied petroleum gas tanks (All types) ferrous metal, Complete at factory (Standard line pressure)
3443523 - - Liquefied petroleum gas tanks (All types) nonferrous metal, Complete at factory (Standard line pressure)
3443531 - - Air receivers (Tanks) Ferrous metal, Complete at factory (Standard line pressure)
3443533 - - Air receivers (Tanks) Nonferrous metal, Complete at factory (Standard line pressure)
3443535 - - Air receivers
3443537 - - Other Ferrous metal pressure tanks (incl Anhydrous ammonia <3000 gallon capacity)(excl range boilers, Expansion, Hot-water storage & Tanks for Water heaters, sold separately)
3443538 - - Pressure tanks (General) + Anhydrous ammonia <3000 gl capacity, excl range boilers, Expansion tanks, etc.
3443539 - - Other Nonferrous metal pressure tanks (incl Anhydrous ammonia <3000 gallon capacity)(excl range boilers, Expansion, Hot-water storage & Tanks for Water heaters sold separately)
3443542 - - Other Pressure tanks (incl Anhydrous ammonia tanks) ferrous & Nonferrous metal, Complete at factory (Standard line pressure)
3443599 - - Metal tanks, Complete (Standard line pressure - Miscellaneous)
34436 - Nuclear reactor steam supply systems + Primary vessels & Tanks, Heat exchangers & Condensers
34437 - Metal tanks, Complete (Standard line nonpressure)
3443712 - - Storage tanks: =<4000 gl capacity: Ferrous
3443715 - - Storage tanks: =<4000 gl capacity: Nonferrous
3443717 - - Storage tanks: >4000 gl capacity: Ferrous
3443719 - - Storage tanks: >4000 gl capacity: Nonferrous
3443748 - - Nonpressure tanks (General) + Tanks for Trailers, Metal septic tanks & Truck tanks for Delivery of Fluids: Ferrous
3443750 - - Nonpressure tanks (General) + Tanks for Trailers, Metal septic tanks & Truck tanks for Delivery of Fluids: Nonferrous
3443799 - - Metal tanks, Complete (Standard line nonpressure - Miscellaneous)
34438 - Metal tanks & Vessels, Custom fabricated
3443803 - - Ferrous metal pressure tanks & Vessels (>24 in. outside diameter & not <5 cu ft capacity) Custom fabricated at the factory, for Refineries, Chemical plants & Paper mills
3443804 - - Pressure vessels & Tanks (>24 in., >5 cuft capacity) + Process vessel: Ferrous
3443805 - - Ferrous metal pressure tanks & Vessels (>24 in. outside diameter & not <5 cu ft capacity) Custom fabricated at the factory, for other Processing industries
3443807 - - Pressure vessels & Tanks (>24 in., >5 cuft capacity) + Process vessel: Nonferrous
3443808 - - Nonferrous metal process pressure vessels, Tanks & Kettles for Refineries, Chemical plants, Paper mills (>24 in. o.d. & not <5 cu ft cap.) Custom fabricated at the factory
3443813 - - Liquefied petroleum gas tanks, Ferrous & Nonferrous, Custom fabricated at the factory
3443814 - - Ferrous liquefied petroleum gas tanks 3000 gallon capacity or more, Custom fabricated at the factory
3443815 - - Liquefied petroleum gas tanks, =>3000 gl capacity
3443816 - - Nonferrous liquefied petroleum gas tanks 3000 gallon capacity or more, Custom fabricated at the factory
3443817 - - All other Ferrous metal tanks & Vessels, Custom fabricated at the factory, incl Anhydrous ammonia tanks 3000 gallon capacity or more
3443818 - - Tanks & Vessels (General) Custom fabricated + Anhydrous ammonia tanks, =<3000 gl capacity
3443819 - - All other Nonferrous metal tanks & Vessels, Custom fabricated at the factory, incl Anhydrous ammonia tanks 3000 gallon capacity or more
3443820 - - All other Ferrous metal tanks & Vessels, Custom fabricated at the factory
3443822 - - All other Nonferrous metal tanks & Vessels, Custom fabricated at the factory
3443899 - - Metal tanks & Vessels, Custom fabricated (Miscellaneous)
34439 - Metal tanks & Vessels, Custom fabricated & Field erected
3443915 - - Ferrous metal bulk storage tanks, Custom fabricated & Field erected, Elevated type, for Dry materials
3443917 - - Ferrous metal bulk storage tanks, Custom fabricated & Field erected, Elevated type, for Water
3443919 - - Ferrous metal bulk storage tanks, Custom fabricated & Field erected, Elevated type, for other Liquids
3443921 - - Bulk storage tanks: Elevated types: Ferrous
3443923 - - Bulk storage tanks: Elevated types: Nonferrous
3443930 - - Bulk storage tanks: Ground storage type: Ferrous
3443931 - - Ferrous metal bulk storage tanks, Custom fabricated & Field erected, Ground storage type, for Dry materials
3443932 - - Ferrous metal bulk storage tanks, Custom fabricated & Field erected, Ground storage type, for Petroleum products
3443933 - - Ferrous metal bulk storage tanks, Custom fabricated & Field erected, Ground storage type, for Water
3443934 - - Ferrous metal bulk storage tanks, Custom fabricated & Field erected, Ground storage type, for other Materials
3443936 - - Bulk storage tanks: Ground storage type: Nonferrous
3443951 - - Ferrous metal pressure vessels & Tanks (incl Gas holders & Process vessels, etc.) Custom fabricated & Field erected, for Refineries, Chemical plants & Paper mills
3443953 - - Ferrous metal pressure vessels & Tanks (incl Gas holders & Process vessels, etc.) Custom fabricated & Field erected, for other Processing industries
3443956 - - Pressure vessels & Tanks + Gas holders & Process vessels, Tanks & Kettles for Refineries, Chemical plants: Ferrous
3443958 - - Pressure vessels & Tanks + Gas holders & Process vessels, Tanks & Kettles for Refineries, Chemical plants: Nonferrous
3443999 - - Metal tanks & Vessels, Custom fabricated (Miscellaneous)
3443XX0 - - Fabricated plate work (Boiler shops - Miscellaneous - Volume)
3443XX2 - - Fabricated plate work (Boiler shops - Miscellaneous - Speciality)