2-11.5NPSH vs R2-1/2: specs compared
Updated 05 September 2026.
75.184 mm
R2-1/2 wins on major diameter
On major diameter, R2-1/2 leads: 75.184 mm versus 59.74 mm.
| Spec | 2-11.5NPSH | R2-1/2 |
|---|---|---|
| Designation | 2-11.5NPSH | R2-1/2 |
| Major diameter | 59.74 mm | 75.184 mm |
| Threads per inch / pitch | 11.5 | 11 |
| Thread form | straight (parallel), 60 degree | tapered, 55 degree |
| Seals on | gasket in the coupling | on the thread flanks with PTFE tape or paste |
Questions and answers
Which has the higher major diameter, 2-11.5NPSH or R2-1/2?
On major diameter, R2-1/2 leads: 75.184 mm versus 59.74 mm.
How do 2-11.5NPSH and R2-1/2 compare?
On major diameter, R2-1/2 leads: 75.184 mm versus 59.74 mm.