Boiler Stacks

Burner Combustion Systems offers boiler stacks from Van-Packer such as the DW & DW Plus, as well as the CS (CM) & CS Plus.

DW & DW Plus Boiler Stacks

Van-Packer Co.’s most popular product, DW, is used for high temperature and combustion gas venting. This product is one of the most versatile in the industry.

Van-Packer Co logo

CS & CS Plus Boiler Stacks

Van-Packer Co.’s CS & CS Plus boiler stacks were specifically designed for special gas venting applications. They have been tested and listed by UL 1738 for venting systems in the following categories: II, III, IV, or in Canada, type BH gas vent. The CS model can be used with appliances that burn natural gas or propane.

The CS (CM) & CS Plus boiler stacks’ standard features include:

  • 4″ I.D to 36″ air space and tested up to 550 ℉ (228 °C) and 5″ water column positive pressure.
  • The flue is capable of being installed in either interior or exterior installations, 2″ clearance to combustibles, with 0″ clearance to non-combustibles.

Van-Packer Co.’s Model CS is identified by the (CM) designation in part identification numbers. An accessory collar (spot welded) has been added to one side (male end) the flange. This allows for an easy connection, especially for larger diameters.

Designation “CM”

Why Van-Packer CO. Uses the Term “CM”

The prefix “CM” lets the factory know that this Model CS part requires a male end collar.


Why The Van-Packer Co. Offers the Male End Collar

  • The Male End collar aids in alignment making the Model CS a user-friendly product.
  • The male end collar serves as a guide when applying sealant to flange.
    While the two sections are being assembled, the male end collar protects sealant from smearing.
  • What is the Difference Between C08STR12BL & CMO8STR12BL?


van-packe boiler stack co8str12bl

Part Identification of the C08STR12BL
  • C – Model CS (NO male end collar)
  • 08 – 08” Inside Diameter
  • STR – Part Code
  • 12 – 12” Long Section
  • B – VP1738 Stainless Alloy Liner
  • L – Aluminized Steel Shell



van-packer boiler stack CMO8STR12BL

Part Identification of the CMO8STR12BL
  • CM – Model CS (WITH male end collar)
  • 08 – 08” Inside Diameter
  • STR – Part Code
  • 12 – 12” Long Section
  • B – VP1738 Stainless Alloy Liner
  • L – Aluminized Steel Shell


Model CS & CS Plus Boiler Stacks

Testing and Applications

Special gas vents CS (with 1″ to 4″ fiber insulation), and CSplus (1″ of airspace) have been tested according to the procedures and methods set forth in UL1738 / UL S636 (Venting Systems For Gas Burning Appliances, Category II, III, &IV). The models CS and CSplus can be used to vent appliances that burn propane or natural gas. These vents can be used with positive, negative and positive vent pressures (40 inch water column maximum positive pressure) and have a maximum operating temperature at 550°F (288°C). These vents can be used in interior and exterior installations.


Listing and Code Compliance

Van-Packer’s Model CS and CSplus special gas vents are listed by Underwriters Laboratories file MH45778 as a “Special Gas Vent” in the United States and as a “Type BH Vent” in Canada when installed in accordance with local and national code requirements and our installation instructions.



Standard and extended warranties are available for Van-Packer Co. boiler stacks (double wall air and fiber insulated special gas vents).


Standard Sizes

4″ I.D. to 10″ I.D. available in 1″ increments and from 10″ I.D. to 48″ I.D. available in 2″ increments.



Vents in the Model CS & CSplus Series are available from 4″ to 36″. I.D. Vents between 38″ and 48″ I.D. require a minimum clearance of 2 inches from combustibles. You must allow a minimum of 5″ clearance for combustibles. You should not place insulation or wrap the vent system in the required space to reduce clearance. Clearance of non-combustibles must be done as per the local code.


Duct Sections & Fittings, Supports & Guides, Penetrations

Van-Packer Co. has a variety of components that can be used to complete any venting system. Straight sections in standard lengths are available in 12, 24, and 36 inches. Variable length sections can accommodate lengths of 5-1/2″ to 18. Van-Packer Co. has many sections with factory-installed pipe nipples that can be used for drainage or effluent sampling. Standard elbows are 15deg, 30deg and 45deg. There are three types of tee sections available: 90deg centered (boot), and 45deg. Plate supports, full angle rings, and breeching hanger band are some of the guides. Wall penetrations, flashings and counter flashings are all possible. Van-Packer Co. also offers adapters, terminations and transitions.


Installation Considerations of Van-Packer Co., Boiler Stacks

Every part of the vent system should be correctly assembled and installed. Incorrect or inadvertent installation could result in the malfunction of the vent system. It is important to follow all local and national codes when installing the vent system.

Vent layouts should be planned carefully to provide enough space for assembly, support installation, connection of supports, and accommodate standard fitting dimensions.

You should not assume that all equipment in a facility can exhaust with one system. Verify compatibility between the equipment and the vapors being vented. Also, check draft requirements. Check with the respective providers.

Consult a design professional as required. For installations that are exposed to weather, a primer coat is recommended and a finish coat of the appropriate paint is recommended.

Sealing draw bands, overlapped, or butted seams. For installations that are exposed to the elements, a suitable sealant is recommended to prevent moisture from entering between the liner and duct shell.