Single Wall & Double Wall

Gas Vent

Special V & 2V Type BH

Special Gas Vent

Special Gas Vent
V Type BH (Single Wall)

  • UL Listed to UL Standard UL1738, ULC-S636-08.
  • Constructed of 444 stainless steel
  • Inner vent diameters range from 8" to 16"
  • Suitable for interior or exterior installation
  • Suitable for use with gaseous fuels venting appliances rated category II, III, and IV
  • Model V Type BH available for Negative & Positive Pressure Industrial or Commercial Appliances up to 50" w.c.
  • Rated for continuous operation at 550 degrees F in United States
  • Rated for continuous operation at 473 degrees F in Canada
Gas Vent

Single Wall Clearances

SINGLE WALL -V VENT DIAMETER (ID) -V THIMBLE ASSEMBLY VENT SHELL DIAMETER (THRU PENETRATION) CLEARANCE TO COMBUSTIBLES (VENT TO CEILING/WALL) -V THIMBLE ASSEMBLY CLEARANCE TO COMBUSTIBLES (SHELL TO JOIST) CLEARANCE TO NON-COMBUSTIBLES THROUGH WALL/FLOOR OPENING
8" 12" 3" 1" 0" 16-1/2"
10" 14" 3" 1" 0" 18-1/2"
12" 16" 4" 2" 0" 20-1/2"
14" 18" 4" 2" 0" 22-1/2"
16" 20" 5" 3" 0" 26-1/2"
* Clearance plates are supplied with all -V thimble assemblies to maintain a minimum 2" clearance to combustibles from the surface of the vent shell for 8" thru 14" diameter, and 3" clearance to combustibles from the surface of the vent shell for 16" diameter. * Clearance plates used with -V thimble assemblies for clearance to combustibles may be removed if a tighter clearance is desired. Vent clearance is from the vent's outer diameter (OD) to the combustible ceiling/wall. The thimble assembly clearance is from the vent's shell OD to the combustible joist. It is important that all clearance to combustibles noted on the UL label are followed.

Special Gas Vent
2V Type BH (Double Wall)

  • UL Listed to UL Standard UL1738, ULC-S636-08.
  • Vent sections are constructed of an inner wall and outer wall with insulation in between - inner vent is Single Wall 444 Stainless Steel and outer shell is 430 stainless steel
  • Inner vent diameters range from 8" to 16"
  • Suitable for interior or exterior installation
  • Suitable for use with gaseous fuels venting appliances rated category II, III, and IV
  • Model 2V Type BH available for Negative & Positive Pressure Industrial or Commercial Appliances up to 50" w.c.
  • Rated for continuous operation at 550 degrees F in United States
  • Rated for continuous operation at 473 degrees F in Canada
Gas Vent

Double Wall Clearances

-2V VENT DIAMETER (ID) -2V THIMBLE ASSEMBLY VENT SHELL DIAMETER (THRU PENETRATION) -V THIMBLE ASSEMBLY CLEARANCE TO COMBUSTIBLES (SHELL TO JOIST) CLEARANCE TO NON-COMBUSTIBLES THROUGH WALL/FLOOR OPENING
8" 12" 2" 0" 16-1/2"
10" 14" 2" 0" 18-1/2"
12" 16" 2" 0" 20-1/2"
14" 18" 2" 0" 22-1/2"
16" 20" 2" 0" 24-1/2"
* 2" clearance to combustibles from the surface of the duct outer shell.
Dye Penetrant Testing All ductwork is tested at the factory
for quality assurance.

Product Resources

The Special Gas Vent -V Type BH Series has been certified by UL. This certification mark indicates that the product has been tested to and has met the minimum requirements of a widely recognized (consensus) U.S. Product safety standard, that the manufacturing site has been audited, and that the applicant has agreed to a program of periodic factory follow-up inspections to verify continued performance.


Model DW-V Type BH is UL Listed under file   number MH60693 and complies with UL 1738, ULC S636-08.

The Special Gas Vent 2V Type BH Series has been certified by UL. This certification mark indicates that the product has been tested to and has met the minimum requirements of a widely recognized (consensus) U.S. Product safety standard, that the manufacturing site has been audited, and that the applicant has agreed to a program of periodic factory follow-up inspections to verify continued performance.


Model DW-2V Type BH is UL Listed under file number MH60693 and complies with UL 1738, ULC S636-08.