U.S. Boiler Company INDEPENDENCE IN3PV, Installation & Operating Manual

12

a.  Clean the male end of each joint using an alcohol 

pad to remove any dirt and grease.

b.  Apply a continuous ¼ inch bead of sealant 

around male end of joint no more than 1/8 inch 

from end.

c.  Align weld seams in pipes and use a slight 

twisting motion to FULLY insert male end into 

female end of joint.  Ensure bead in male end of 

pipe is below locking band and rest against the 

end of the female pipe.  Verify the factory-

installed gasket is not dislodged or cut.

d.  Smooth sealant around joint for a continuous 

seal.  Reapply sealant if necessary.

e.  Tighten locking band by HAND with a 5/16" nut 

driver until snug plus ¼ turn.  DO NOT 

SECURE JOINTS WITH SHEET METAL 

SCREWS OR POP RIVETS.  DO NOT 

PUNCTURE THE VENT SYSTEM!

f.  Once the installation is complete, operate boiler 

and inspect all joints to ensure that flue gases 

and/or liquid condensate will not escape. 

length of 12¾ inch and can adjust across a 7 inch 

gap up to a maximum of 19¾ inch long.  (Note for 

the adjustable pipe the installed length should be 

measured from the centerline of the bead on the 

male end of the first pipe to the end of the female 

pipe excluding the locking band of the second pipe 

with a single gasket.)  

WARNING

Never exceed maximum installed length of 19¾ 

inches for adjustable length pipe.

Risk of flue gas leakage is possible.

  Only in the event the adjustable length pipe is not 

sufficient a standard length pipe may be cut using 

the following procedure.

  Carefully cut pipe to length using a hacksaw with 

minimum 32 teeth per inch or circular saw with 

metal abrasive wheel.  Remove male (bead) end 

only – female (bell) end accepts next fitting or pipe.

NOTICE

Cut  must  be  square  with  pipe  and  filed  or 

sanded smooth before joining.  Carefully ensure 

roundness of cut pipe by hand with gloves before 

installing.    Seal  joint  with  RTV  specified  in  this 

manual.

6.  Seal all U.S. Boiler Company Gasket-Less vent, U.

S. Boiler Company mixed vent (Gasket-Less and 

Gasketed) and field cut joints using Dow Corning 

Silastic 732 RTV, Dow Corning Silastic 736 RTV, 

GE RTV106, Polybac #500 RTV, Sil-bond RTV 

4500 (Acetoxy) and Sil-bond RTV 6500.  Do not 

use other adhesives or sealants.

E. 

 Install Vent Pipe, U.S. Boiler Company Gasketed 

Vent System.

1.  Procedure for Joining U.S. Boiler Company 

Gasketed Vent Pipe and Fittings.  See Figure 8A.
a.  Wipe the male end of each joint using an alcohol 

pad to remove any dirt and grease.

b.  Align weld seams in pipes and use a slight 

twisting motion to FULLY insert male end into 

female end of joint.  Ensure bead in male end of 

pipe is below locking band and rest against the 

end of the female pipe.  Verify the factory-

installed gasket is not dislodged or cut.

c.  Tighten locking band by HAND with a 5/16" nut 

driver until snug plus ¼ turn.  DO NOT 

SECURE JOINTS WITH SHEET METAL 

SCREWS OR POP RIVETS.  DO NOT 

PUNCTURE THE VENT SYSTEM!

d.  Once the installation is complete, operate boiler 

and inspect all joints to ensure that flue gases 

and/or liquid condensate will not escape.  

F. 

 Install Vent Pipe, U.S. Boiler Company Gasket-Less 

& Gasketed Vent System.

1.  Procedure for joining the male end of U.S. Boiler 

Company Gasket-Less Vent with the female end of 

U.S. Boiler Company Gasketed Vent.  See Figure 

8B.

Figure 8A:  U.S. Boiler Company Gasketed Vent Joint Detail

Figure 8B:  U.S. Boiler Company Gasket-Less Male and

Gasketed Female Vent Joint Detail

V. Venting (continued)