DuraVent CVS Telescoping Adjustable Length: a sliding section for the last few inches
The DuraVent CVS Telescoping Adjustable Length is a sliding vent section that joins straight CVS pipes. It fills the gap when fixed lengths don’t reach, since CVS pipe cannot be cut to fit. The three included screws hold it at your chosen length. Keep at least 1/2 inch of overlap. CVS is DuraVent’s concentric vent: the exhaust runs up a 3 inch inner pipe while combustion air comes in through the 5 inch outer pipe around it. Both use one opening through the wall or roof. It serves pellet and gas appliances whose makers approve CVS.
Choose your finish and adjustment range on this page. The 9 to 12 inch version comes only in galvalume, a metal finish. The 12 to 18 inch version comes in galvalume or painted black. When planning the run, subtract 1 1/4 inches at every joint because each pipe slips into the next. That overlap affects how much length you need this section to fill. Need the straight sections too? See the DuraVent CVS Vent Pipe Length straight pipe. The DuraVent CVS Telescoping Adjustable Length ships free from My Cozy Outdoors with No Sales Tax (except WY) and the full manufacturer warranty.
Details
SKU: 35CVS-12TA | 35CVS-18TA | 35CVS-18TAB
Applications
Concentric Venting System (CVS) (direct vent or two-pipe system) for use with condensing natural gas or propane Categories II, III and IV appliances or Canada’s Type BH Gas Vent Systems, (having a maximum rated operating temperature of 500°F). For use with Stoves and inserts of Type L gas, pellet, oil, corn and biofuel (Rated to a continuous use flue temperature up to 570°F). CVS can be used on a wide range of appliances, including: gas boilers, warm air furnaces, water heaters, unit heaters, tankless water heaters, pellet stoves, direct vent gas or propane stoves, heaters, and fireplaces.
Materials and Construction
Unitized concentric construction. Inner: Laser-welded UL approved 444 super-ferritic stainless steel .012″ Outer: Laser-welded, paintable, zincalume .018″ Silicone O-ring seals on inner liner and outer wall. Precision twist-lock connection on outer wall.
Clearances
CVS is listed to 0” clearance as a double-wall vent system for Category II, III, and IV appliances, for flue temperature of up to 400°F for horizontal enclosures, and up to 480°F for vertical enclosures. CVS must maintain 1” clearance to combustibles when used with pellet fuel. When CVS is used as a concentric/direct vent system on gas, the clearance to combustibles is specified by the appliance manufacturer.
Diameters
3″ inner and 5″ outer.
Listings
CVS vent pipe is listed to UL 1738 (MH25700) as a double-wall vent system for Category II, III and IV appliances. It is pressure rated to 10 WC for the inner pipe. This product is also intended to be used as a direct vent system for Listed to UL 1738 (DGSH.MH25700) and ULC S636 (DGSH7.MH25700). Pressure rated to 10” W.C. Listed to UL 641 (DFTX.MH8381), ULC S609 (DFTX7.MH8381), and ULC/ORD 441 (DFVAC.MH21150). Listed in combination with gas appliances, has been tested and listed as a decorative gas appliance system or as a direct vent heater system. Check with your appliance manufacturer for approval.