This unique wall thimble has a built-in 18" section of adjustable pipe which goes to the inside of your structure giving you a lot of flexibility when running the vent pipe to your heater. The pipe is also sealed to the thimble so there is no air leakage to worry about. This thimble is for walls 4 1/4" to 8 1/2" thick (extensions are available for thicker walls). The stainless steel heater vent pipe and fittings feature patented built-in mechanical locking band and triple-lipped directional gaskets. All pipes and components are engineered with smooth clean welds located 90° from mechanical locking bands. All pipe and fittings are UL1738 approved for category II, III and IV venting applications.
What is UL 1738? In short, it is a US standard for gas venting systems required in category III applications. Category III refers to positive vent pressure which is created by exhaust blowers in unit heaters. These vent systems must be constructed of AL29-4C® stainless steel, contain gaskets for sealing, and have a built in mechanical locking band among other requirements.
- Built-in adjustable 18" vent pipe
- Made of AL29-4C® super-ferritic stainless steel
- Built-in high temp silcone gaskets for air tight seal
- Built-in locking band to insure a secure fit (no hardware needed)
- UL1738 approved for category II, III and IV appliances.
- Limited lifetime warranty
Item # 4650160, 4651160