PVC/NBR Thermal InsulationPipe /Thermal Insulation Material features good heat protection, strong load bearing, non-water absorption, high resistance to acid and alkali. Thermal InsulationPipe Inner Size(mm)Copper Pipe Size(Inch)Iron Pipe (DN)6(S) Size9(N) Size13(T)Size19(NT) Size25(TF) Size32(TT)Size61/4"66*109*613*6103/8"6*129*1013*10121/2"86*159*1213*1219*12155/8"6*199*1513*1519*15193/4"156*229*1913*1919*1925*1932*19227/8"6*259*2213*2219*2225*2232*22251"206*289*2513*2519*2525*2532*25281-1/8"9*2813*2819*2825*2832*28321-1/4"9*3213*3219*3225*3232*32351-3/8"259*3513*3519*3525*3532*35381-1/2"9*3813*3819*3825*3832*38421-5/8"329*4213*4219*4225*4232*42451-3/4"13*4519*4525*4532*45481-7/8"4013*4819*4825*4832*48542-1/8"13*5419*5425*5432*54572-1/4"13*5719*5725*5732*57602-3/8"5013*6019*6025*6032*60767019*7625*7632*76898019*8925*8932*89 Thermal InsulationPipe for example: 19*89, it means the 19(NT)Thermal InsulationPipeinner size is 89mm. Aboutthe Thermal InsulationPipe inner size ≥89mm, we suggest use the same thickness of the plate.