Exactly my concern. How would you know? These parts are seeing moisture. When your done sledding for the day and shut off your machine Im assuming the valve shuts also, leaving as easy place for an ice build up.
Edit: ya beat me to it Scott! I'm either to dang slow at typing, or I ramble on to much!
I incorporated several safety feaures when designing the roll-over valve system, for this very concern.
The valve used is a normally open, solenoid type valve. What this means is the valve remains open until voltage is applied to it. The valve is spring loaded to the open position.
The valve remains open while the sled is shut-off and while the engine is running. So for example if there is moisture in the vent line and the sled is outside in freezing weather, the ice could freeze it in open position only. It is a much safer design then using a normally closed valve. Which would freeze in the closed position. Once the engine is started,warm air flowing through the vent line, thaws out the moisture.
I recommend warming the engine up for a few minutes before trying to activate the roll-over valve after it has been sitting out in freezing weather. For example if you want to flip the sled on it's side first thing in the morning, to perform some suspension adjustments etc.
Additionally the valve is installed directionally. The valve has a flat disc that seals against the body when closed. When the valve is installed correctly, with the "short fitting" towards the oil tank. In the un-likely event a valve trys to stick closed, positive oil tank pressure from a running engine will actually force the valve off of it's seat to open and vent. Its the same principle as how a safety pressure relief valve operates.
If the valve is installed in-correctly (backwards), the oposite would be the effect in that positive oil tank pressure could force a sticking valve to lock on to its seat. Not allowing the oil tank to vent. There are instructions in the box with the kit and pic's on my web site show the correct way to install the valve.
There are also electrical safety features as well.
The red flashing LED is wired into the same circuit as the shut-off valve. It will flash anytime anytime voltage is being applied to the valve to close it.
I designed the Roll-over valve system with a LED for two reasons.
First as a warning light, you should never see the LED on/flashing any time the engine is running. If you do, shut the engine off imediately, and investigate the cause. If your out in the back country the entire system can be bypassed by simply un-pluging the plug and play connectors and pluging the kill switch harness back to stock. Or on non-plug and play models remove the fuse and or un-plug the conncetor to the valve.
Second, the LED is a reminder light. For example if I activate the system to roll my sled over to get un-stuck, then flip the sled back upright and deside to take a quick breather. If I look down and see the LED flashing, it tells me that I need to turn the key off!
The tether switch itself is a built-in safety feature as well. It is a dual pole switch and will either be up (tether cord in) or down (cord pulled) and only one set of contacts can have continuity at a time. Either the main contacts will be closed and roll-over contacts will be open. (engine running/valve off, cord in). Or the main contacts will be open and the roll-over contacts closed. (engine off/valve closed, key on tether cord pulled) Not both at the same time!
During the engineering/R+D phase of the Roll-over valve system, I also had a pressure sensor and vacuum/pressure gauge installed on my sled. This was so I could monitor breather vent flow/pressure during real world riding conditions. I wanted to make sure that the valve has the ability to allow for proper air flow.
Bill