Boiler_Flue_Material_Specification.pdf

Cincinna� Northern Kentucky Airport Addendum #1

Industrial Rehabilita�on and Efficiency Program April 18, 2025

CONDENSING BOILERS 235216.00 - 1

2.5 BREECHING, CHIMNEY & STACK

A. Manufacturer shall provide factory-built modular universal stack/vent system tested and listed by Un-derwriters Laboratories Inc. (UL) for use with eight (8) different UL Duct/Chimney/Vent Standards ranging from building heating appliances chimneys (pressure stacks), 1400˚F chimneys (engine ex-haust), gas vents for condensing appliances, low temperature oil fired equipment, and kitchen exhaust

(grease duct). UL Listings shall include:

a. UL 103 Standard for Building Heating Appliance Chimneys which may produce exhaust gas at temperatures not exceeding 1000˚F under continuous operating conditions and

1400˚F under intermittent condition when burning gaseous, solid, or liquid fuels as de-scribed in NFPA-211

b. Additional UL 103 Type HT 2100˚F burnout test for Solid Fuel.

c. UL 2561 1400˚F Chimney for appliances which may produce exhaust gas at temperatures not exceeding 1400˚F under continuous operating conditions and 1800˚F under intermittent con-ditions.

d. Additional UL 103/2561 pressure testing for positive pressure applications up to 90 inches

W.C. after 1400°F continuous exposure.

e. UL 1738 Standard for Venting Systems for Gas-Burning Appliances, Categories II, III, and

IV, with operating flue gas exhaust temperatures up to 550°F continuous, and/or 480°F continuous.

f. UL 441 Standard for Gas Vents, for appliances listed for use with Type B Gas Vent, with operating flue gas exhaust temperatures up to 480°F continuous.

g. UL 641 Standard for Type L Low-Temperature Venting Systems, suitable for use with ap-pliances approved for use with Type L Venting Systems, with operating flue gas exhaust temperatures up to 570°F continuous.

h. UL 1978 Grease Duct for use with commercial cooking equipment, as described in NFPA-

96, which may produce temperatures not exceeding 500˚F under continuous operation and

2000˚F for 30 minutes.

1.2 CONSTRUCTION

A. The double wall fiber insulated exhaust system shall be constructed of all-stainless steel. The materi-als and construction of modular sections and accessories shall be as specified by the terms of the product’s UL listing.

a. Type 444 stainless steel inner liner.

b. 1-¼” minimum thick fiber insulation.

c. Type 304 BA stainless steel outer jacket.

d. The entire exhaust system, including all accessories (connectors, hardware, anchor plate supports, guides, drains, and terminals), shall be Type 304 stainless steel.

Cincinna� Northern Kentucky Airport Addendum #1

Industrial Rehabilita�on and Efficiency Program April 18, 2025

CONDENSING BOILERS 235216.00 - 2

B. Inner flue shall have an overlapping male/female socket that protects the rolled flange with seal-ant against condensate and high-pressure cleaning. The inner joints shall be secured with vee bands on the inner and overlapping locking band on the outer jacket.

C. Double-wall exhaust system shall be constructed so the outer jacket is floating and not welded to the inner liner.

D. Exhaust system shall be designed to compensate for all temperature induced thermal expan-sion, installed to be gastight, and thus prevent leakage of combustion products into a build-ing.