Air Dryer Bypass

[hyjaxe]

Question for you guys who run air dryers. I recently got a Ingersoll Rand D42IT air dryer. Is it generally safe to run the compressor with the dryer unit off, like where you only need it for a short period. Or do I need to install a bypass? Wasn’t sure if the unit internals would get damaged etc

 

[MacMcMacmac]

No, there is no risk to the internals.

Keep in mind that it takes time to bring the internal temperature of a refrigerated dryer down to operating temperature, so you can't just flick it on like a lightbulb when you need dry air, then switch it off again. You probably already knew that, but I figured I'd cover the bases anyway.

Wet air will get past the dryer though.

 

[cretedog]

Question for you guys who run air dryers. I recently got a Ingersoll Rand D42IT air dryer. Is it generally safe to run the compressor with the dryer unit off, like where you only need it for a short period. Or do I need to install a bypass? Wasn’t sure if the unit internals would get damaged etc

I installed a bypass- more so to take the dryer out of the system if it ever had problems. Fine for 10 years then recently I was glad I did. A part failed causing a leak. Took a couple of weeks to get the part. Closed two valves and opened one and no down time or re-piping needed.

 

[Beerhippie]

Installed a bypass when I installed the D42 here. It also bypasses the secondary coalescing filter and microfilter, so I can clean/change elements without cutting the air supply.

I also plumbed the dryer with PEX and Sharkbite fittings, so if I need to take it out of the system for any reason, I can "jump" it and still use the filters.

Damned glad I did both of those, as I've had to replace the unit twice this year.

 

[hyjaxe]

No, there is no risk to the internals.

Keep in mind that it takes time to bring the internal temperature of a refrigerated dryer down to operating temperature, so you can't just flick it on like a lightbulb when you need dry air, then switch it off again. You probably already knew that, but I figured I'd cover the bases anyway.

Wet air will get past the dryer though.

Thank you guys for the quick replies! I appreciate it. Yes, the manual states at least 10 Min (I believe or more) run time prior to opening the compressor.

 

[RichardK]

No, there is no risk to the internals.

Keep in mind that it takes time to bring the internal temperature of a refrigerated dryer down to operating temperature, so you can't just flick it on like a lightbulb when you need dry air, then switch it off again. You probably already knew that, but I figured I'd cover the bases anyway.

Wet air will get past the dryer though.

Hi Mac,

I too am installing a dryer. It's an Airbase Industries PDRCF1150029 on an emax 5hp 80 gallon compressor. Manual says "Avoid leaving the dryer off when compressed air is still flowing through it."

I was wondering if I can do exactly that, and what the concern might be.

Thanks,
rich

 

[Beerhippie]

Keep in mind that these dryers go into a "Standby" mode when you're not using air--at least, ours does--so the electrical draw should be very low when not in use.

As @MacMcMacmac pointed out, they take a while to get down to operating temps after being shut down. On standby mode, they're ready go on demand.

 

[RichardK]

Thanks and copy. It's kinda why I'm asking is I'm not seeing a "standby" mode, at least explicitly. Not sure why I'd ever want to not use it, but the curiosity is there.

I wasn't going to, but I think I'm going to build a bypass circuit for the dryer. There are some good examples here.

Cheers,
rich

 

[MacMcMacmac]

If the dryer has an electric drain, i could see it becoming a reservoir for condensate if it isn't draining. Other than that, maybe they don't want any internal separators gumming up with debris. If it's a high temp dryer, they probably don't want hot air going through it with the aftercooler not running.

There may not be much water to separate out in the winter months, hence the temptation to run air through it when it isn't operating.