Ken,
I used that number under a Parker search site and came up with manifold fittings so I think you might have read the PN for a part that was on the accumulator/dryer. Take another look and see if there are other PNs, perhaps under the holding clamp.
Worst case pull it and take it in to a supplier. These are quite common parts and your coach may possibly have the part listed in the back closet. The length, port fittings, and diameter may be a good way to track one down short of having a PN.
A call to BCS may also yield a PN and part. My guess is they used the same part on many coaches.
Later Ed