The 2 Inch to 1 Inch reducer was built for the RV-10 to route 1 inch scat tube around the Andair valve in the consol. It is made of stainless steel because it has been assembled from parts we already make for the heater bypass valve and firewall penetration kit, it is light, has bolt holes to mount it, and is inexpensive.
2 Inch to 1.5 Inch Reducer (Aluminum)
The 2 inch to 1.5 inch reducer was made to increase the heat output of the heat muff on an RV-4. In cold conditions there was insufficient heat in the cabin. However when we reduced the scat tube from 2 inch to 1.5 inch, the air was retained in the muff long enough to heat sufficiently and deliver good volume.
Firewall Penetration Kit
• Fireproof seal of the firewall for penetration of wires and cables.
• Seals out moisture and gasses.
• Easy replacement of wires and cables if necessary.
• Very clean looking installation.
• Available in three sizes.
• Hardware for attaching the unit to the firewall of the aircraft NOT included
To determine the size you need, plan where you want to run your wire and cable bundles. Use a tie strap or twist tie to bundle the wires and cables. Measure what size holes the bundle will fit through and choose the NEXT LARGER size (see installation instructions.) You need enough clearance between the bundle and stainless fitting to push the second fire sleeve into the fitting creating the fireproof, chafe proof seal.
Typical installation. Wires can be run straight out or turned back to attach on firewall reducing vibration.
They are so effective that they received an STC under Advisory Circular AC 20-135 Power plant Installation and Propulsion Systems Component Fire Protection Test Methods, Standards and Criteria.
During the testing phase of our all stainless steel heater bypass valve, we were astounded at the affects of a simulated engine fire on aluminum firewall components. Watching how fast the aluminum melted away (only 16 seconds) took us by surprise. It became very apparent that fireproofing the firewall was more important than most people realize. Testing was initiated on most common methods of wire and cable penetrations available on the market. Simulated engine fire was directed at the stainless shields with rubber grommets, high temperature silicone, eyeball fittings, plain rubber grommets and several untried methods. All failed the fire test with the exception of the steel eyeball, and it only accepts one cable.
After many months of trial and error, a fireproof pass through was designed. The firewall Penetration Kits offer a fireproof method of getting wires and cables trough the firewall in a clean, professional looking manner that allows easy removal for replacement if necessary.
During testing of our firewall penetration kits, we wanted a fireblock material to seal the stainless steel fitting to the firewall and seal out moisture and gas from the other end. Many months of testing resulted in the use of BIOTHERM 100. Very nice for sealing the firewall on the RV-10.
The reasons for settling on this material are as follows:
Testing on “high temp” silicone sealer revealed that “high temp” for common silicone meant burning at about 600 degrees. Unacceptable with windblown Avgas burning at 1875 degrees. We tried Intumescent Sealers. Intumescent meaning they expand with heat, supposedly sealing voids better. The problem with intumescent sealers is that they start to expand at 250 degrees. Not a good program right next to a cylinder that runs 350 degrees or hotter. The BIOTHERM 100 proved through testing to be the best material available for the application of sealing out flames on the firewall. It is easy to apply, stays flexible, it’s not intumescent, and blocks fire to 2000 degrees. Available in .33814oz 10ml.
Heater Bypass Valve
The HBV-2 is designed for the RV7, RV8, or RV9 aircraft where the air is distributed in the cabin through a plenum.
The HBV-10 is a set of two that have offset levers to clear the upper nose gear mount.