Brochure
28% UP
CHIMNEY
LOWER EFFICIENCY - before 1992
HEAT DISTRIBUTION
400 - 550F
70% TO HOUSE
2%
STANDBY
18% UP
CHIMNEY
HIGHER EFFICIENCY - after 1992
275 - 450F
80% TO HOUSE
2%
STANDBY
Higher Efficiency Produces 
Lower Stack Temperatures
1 2
Z-Flex 
IS THE LEADING MANUFACTURER 
OF SPECIALTY VENTING SYSTEMS FOR 
FURNACES, BOILERS, WATER HEATERS, 
OIL HEATERS, FIREPLACES, AND MORE.
Z-FLEX has been providing flexible 
answers to gas, oil, pellet and wood 
venting applications since 1979. 
We have pioneered flexible chimney 
liner solutions and special gas vent 
(AL29-4C
®
). 
A variety of innovations in materials 
and construction have led to products 
that deliver: 
• Superior performance and 
increased efficiency 
• Easier handling and faster, 
simpler installation 
• Greater reliability, safety and 
increased service life
To that we add responsive 
customer service along with 
expert technical support.
SPECIALISTS 
IN FLEXIBLE  VENTING SOLUTIONS
Safety Issues
Since  the  federal  government  required  modern  heating 
equipment  to  achieve  higher  efficiencies  in  1992,  safely 
venting  them  has  become  more  of  a  challenge.  Today’s 
more  efficient  equipment  produces  lower  flue  gas 
temperatures  than  pre-1992  equipment.  The  low 
temperature flue gas provides little natural draft in chimneys 
and is more likely to condense into an acidic, and corrosive, 
solution. The result can cause property damage, personal  
injury, or death. The natural laws of physics that control this 
phenomenon  pertain  to  all  gas  and  oil  fired  equipment. 
Our  three  major  product  lines;  chimney  liners,  special  gas 
vent (AL29-4C® stainless steel), and flexible vent connectors 
are  all  designed  to  prevent  flue  gas  condensation  or 
protect  against  its corrosive  effects.  Most  of  the  products
Z-FLEX has developed are now recommended or required by 
the  following  national  codes  and  testing  agencies: 
1992 National Fuel Gas Code 
• Venting Tables for sizing Chimney Liners and 
Vent Connectors when adding or replacing equipment 
• Insulated Connectors required in attics and 
other “cold” spaces 
1997 NFPA 31 “Installation 
of Oil Burning Equipment” 
• Venting Tables for sizing Chimney Liners 
International Approval Services 
(formerly AGA) 
• June, 1996 – IAS requires all Category III gas boilers 
and furnaces to use a UL 1738 approved vent system 
(like our Z-Vent) 
• July, 1998 – IAS requires all Category III gas residential 
unit heaters to use a UL 1738 approved vent system 
(like our Z-Vent) 
Advanced Products
 FOR MAXIMUM PERFORMANCE
Advanced Products
 FOR MAXIMUM PERFORMANCE
• PATENTED TRIPLE-LOCK DESIGN 
FOR STRENGTH 
• COMPRESSED TO LOWER 
SHIPPING COSTS 
• BEST AVAILABLE 
MATERIALS/ALLOYS 
• 20+ YEARS OF MANUFACTURING 
EXPERIENCE 
• “IMMEDIATE” AVAILABILITY 
(24–72 HR. LEAD TIME) 
• LISTED BY UNDERWRITERS 
LABORATORIES







