Insulation; Piping Size - Mitsubishi Electric P Series Installation Manual

11.1. Insulation

the refrigerant and drain pipes. When using commercially available
refrigerant pipes, be sure to cover with available insulating material
with heat-resistant temperature of more than 100 °C [212 °F] and
thickness given below, on both liquid and gas pipes. Insulate all indoor
pipes with polyethylene insulation with a minimum density of 0.03 and
Pipe size
6.4 mm to 25.4 mm [1/4 to 1 in.]
28.6 mm to 38.1 mm [1-1/8 to 1-1/2 in.]
-If the unit is used on the highest story of a building and under high
temperature and high humidity, it is necessary to use thicker insulation

11.2. Piping size

Model
Liquid pipe
Refrigerant
pipe Gas pipe
Drain Pipe
18
Insulation thickness
>10 mm [7/16 in.]
>15 mm [5/8 in.]
PVA-AA7
12-18 24-30-36-42
6.35 mm [1/4] 9.52 mm [3/8]
12.7 mm [1/2] 15.88 mm [5/8]
O.D. 32 mm [1-1/4]