The rain water pressure tank has been relocated.

Let me be perfectly clear with this post.  I am not a plumber.  I am not an expert on building codes.  I'm making this post to show what I did in my situation.  It is not intended to be a how-to guide.  Always seek qualified professionals when making home improvements.

That said, I finally got around to relocating my pressure tank to my crawlspace.  I don't know if it was absolutely necessary (again, I'm not a plumber) but I thought that getting it out of the elements was a good idea.  It's also cooler down there so it won't be subjected to the high (90+ degree) heat and temperature swings.  Also, I won't have to drain and move it in the winter.

I used the following:

• 3/4" slip x 1/2" FPT PVC elbows
• 3/4 in. Schedule 40 PVC Tee
• 3/4 in. x 3/4 in. x 1/2 in. PVC Sch. 40 S x S x Female Pipe Thread Reducing Tee
• 3/4 in. PVC Sch. 40 Female S x FPT Adapter
• 1/2-Inch Pressure Relief Valve
• 1/2 in. Brass Push-to-Connect x Male Pipe Thread Adapter 
• 1/2 in. Brass 1/4 Turn MPT x MHT No-Kink Hose Bibb 
• 3/4 in. PVC Sch. 40 Pipe

I glued all of the PVC connections and used thread sealant on the brass fittings.

The pressure tank is rated to 100 psi.  The pump that I have shuts off at 55 psi.  In theory the pump should never cause enough pressure to make the tank fail.  I didn't want to take any chances.  I got a spring loaded pressure relief valve that opens at 75 psi.  The hose connection allows me to drain the pressure tank, and the other connect attaches to the existing PEX pipe I recently ran through my crawlspace.

The above picture shows the tank in its final location.  It's against the wall out of the way near my water heater.