LP usage should be limited to interior applications, originating from the second stage regulator to the appliance.
NOTE: Not suitable for use underground

Type "L" tubing is typically used for both internal, external, and inground applications. LP usage is acceptable downstream of the first stage regulator. Type "L" may also be used downstream of the second stage regulator if desired.

Type "K" tubing is typically used for both internal, external, and in-ground applications. LP usage is acceptable for tank vapor pressure and liquid applications (i.e. fill station bypass lines).