The Castair RDD40-OGK is the O-ring and gasket kit for the RDD40 refrigerated compressed air dryer. When your RDD40 starts leaking at connection points, around drain fittings, or at heat exchanger seals, the problem is almost always worn or cracked O-rings and gaskets rather than a failed unit. This kit gives you the correct seals specific to the RDD40 so you can restore a leak-free seal without hunting down generic hardware store parts that may not be the right material or durometer for refrigeration service.
This is a service part. If you are performing scheduled maintenance on an RDD40 dryer — particularly after refrigerant service, drain valve replacement, or heat exchanger service — replacing the O-rings and gaskets at the same time costs very little and prevents a callback. If you are sourcing this for a repair, have your dryer serial number and unit age available when you call, as seals degrade faster in high-temperature or high-humidity environments.
What This Kit Covers
- O-ring set: Replacement O-rings for the RDD40 refrigerated dryer — specific to this model
- Gasket set: Replacement gaskets for drain connections, heat exchanger access points, and service ports
- Application: Castair RDD40 refrigerated compressed air dryer series
Note: This kit is designed specifically for the RDD40 model. It is not compatible with other Castair dryer models (RDD50, RDD80, RD25-6K, RD59-11K, RD71-15K, or others) without confirming fitment. Call 866-217-0063 to confirm compatibility before ordering.
When You Need This Kit
- Air or refrigerant leaks detected at connection points or service ports on the RDD40
- Scheduled preventive maintenance — recommended any time the dryer is opened for service
- After refrigerant recharge or drain valve replacement
- Any time seals show visible cracking, compression set, or deformation on inspection
What's in the Box
- O-ring set for Castair RDD40 refrigerated dryer (model-specific)
- Gasket set for Castair RDD40 refrigerated dryer (model-specific)
Note: Detailed contents list varies by kit revision. Full contents are confirmed by the kit part number RDD40-OGK. Contact us for complete contents if needed before ordering.
Compatible Equipment
- RDD40 series: Castair RDD40.016, RDD40.030, RDD40.060, and related RDD40 variant dryers
- Not compatible with: RDD50, RDD80, or the RD-series dryers (RD25-6K, RD59-11K, RD71-15K) without confirmed fitment
Technical Specifications
- Part Number: RDD40-OGK
- Manufacturer: Castair (Cast Air, Inc.)
- Application: Castair RDD40 refrigerated compressed air dryer
- Kit Type: O-ring and gasket service kit
- Material: Contact us for specific O-ring material specification — important for refrigerant compatibility
Why Buy From Air Compressor Factory Direct?
We specialize in Castair compressed air equipment and service parts. We can confirm kit compatibility with your specific RDD40 unit before you order — important if you are not sure which sub-variant of the RDD40 you have. Free shipping on qualifying orders, free pre-sale technical support, and genuine Castair parts with full manufacturer warranty.
Call 866-217-0063 for quick answers and help!
