Fiberglass (FRP) Ducts and Fiberglass Fume Stacks

A ventilation system, of FRP cylindrical ductwork and fume stacks, is a low cost, maintenance-free way to remove corrosive chemical fumes and provide proper ventilation in corrosive environments.

Bittner manufactures FRP ductwork and fume stacks up to 72 inches, to your specifications and may be made fire-retardant and / or heat resistant, to withstand high temperatures. Using additives or specialized resins during the manufacturing of duct systems has allowed installations to operate in temperatures of 400 F for years. Bittner recommends that all stacks be manufactured of fire-retardant resins. Properly installed FRP stacks and ductwork of fire retardant resins have prevented fire from causing major damages to life and property.

Benefits that make Bittner’s FRP ductwork and fume stacks dependable:

• From 2 inches up to 72 inches in diameter
• A smooth interior layer that has a resin-rich interior surface which reduces air turbulence.
• Exacting standards of manufacturing provide years of dependable trouble-free service.
• Lightweight for ease of installation requiring fewer hangers than metal ductwork.
• Compare the specific gravity of FRP - 1.3 to 1.7 with the specific gravity of steel - 7.85
• Can operate in temperatures up to 400° F
• Duct Plain or flanged end sections, in diameters from 2 inches to 60 inches, with larger diameters available on request.
• Contact-molded throughout according to the latest ASTM Standards. It is made to the minimum wall thickness shown
  in the Round Duct Specification Chart. Heavier wall thickness can be made if your specifications require them.
• Low-cost
• Maintenance Free
• Can be fire retardant (depends upon additives)
• Can be made "electrically conductive" for specific applications.
  

Fiberglass Fume Stacks will complete your ventilating system. Stacks are manufactured in diameters up to 12 feet and designed to be free standing or guyed to the height required. Bittner recommends all fume stacks from 50 feet or more in height be manufactured by filament-winding. This process gives the fume stack added strength to withstand maximum wind loads. Stack accessories are custom designed to your individual requirements. We can provide rain caps, round and rectangular inlets, and a variety of nozzles. Guy wire attachments, guy wire, shackles and turnbuckles needed to meet the tension requirements for your installation are also available. Our duct has a safety factor of 10:1 in accordance with applicable ASTM specifications

Round Duct Specifications

Wall Thickness (min) inches	Allowable Vacuum inches of water	Allowable pressure inches of water	Flange diameter (O.D.) inches	Flange Thickness inches	Bolt circle diameter inches	Bolt hole diameter inches	No. of bolt holes
0.125	405	750	6-3/8	1/4	5	7/16	4
0.125	405	500	7-3/8	1/4	6	7/16	4
0.125	210	410	8-3/8	1/4	7	7/16	4
0.125	64	350	10-3/8	1/4	9	7/16	8
0.125	30	180	12-3/8	1/4	11	7/16	8
0.125	16	340	14-3/8	3/8	13	7/16	12
0.125	9	280	16-3/8	3/8	15	7/16	12
0.125	7	220	18-3/8	3/8	17	7/16	12
0.125	6	290	20-3/8	1/2	19	7/16	16
0.125	5	240	22-3/8	1/2	21	7/16	16
0.125	5	190	24-3/8	1/2	23	7/16	20
0.187	9	140	28-3/8	1/2	27	7/16	20
0.187	7	100	34-3/8	1/2	33	7/16	28
0.187	5	70	40-3/8	1/2	39	7/16	32
0.250	10	120	46-3/8	5/8	45	7/16	36
0.250	9	100	54-3/8	5/8	52	9/16	44
0.250	7	80	60-3/8	5/8	58	9/16	44
0.250	6	60	66-3/8	5/8	64	9/16	52