If you purchase the new Fabco NV-55-18 needle valve with 1/8” NPT ports and you want to hook it up for inline use or connect it to 1/8” ID tubing, this is one way to do it. I picked up the following parts made by WATTS in the plumbing section at Lowes. I mention this because you may want to use this needle valve down the road instead of the regular NV-55 with #10-32 threads. Note that you will need two of each part for inline use. Lowes did not carry the 1/8” Barb x 1/8” MIP adapter that would be much simpler to use. Swagelok has its set of nicer tubing adapters and I didn't list these parts.
WATTS A-85 Hose Barb Adapter (1/8" Barb x 1/4" MIP) [$2.91]
WATTS A-734 Pipe Reducing Coupler (1/4" FIP x 1/8" FIP) [$2.56]
WATTS A-715 Brass Pipe Nipple (1/8" MIP x Close) [$2.60]
Fabco NV-55-18 Needle Valve [$34.75]
WATTS A-85 Hose Barb Adapter (1/8" Barb x 1/4" MIP) [$2.91]
WATTS A-734 Pipe Reducing Coupler (1/4" FIP x 1/8" FIP) [$2.56]
WATTS A-715 Brass Pipe Nipple (1/8" MIP x Close) [$2.60]
Fabco NV-55-18 Needle Valve [$34.75]
