Siemens SITRANS P Compact Operating Instructions page 92

Sealing plug / thread adapter
B.4 Dimensional drawings for accessory part
Thread adapter Ex d, M25 x 1.5 on M20 x 1.5 and
M25 x 1.5 on ½-14 NPT, dimensions in mm
Sealing plug Ex d ½ -14 NPT
92
①
Sealing ring: Use for dust protection "Ex t" type of
protection.
Compact Operating Instructions, 01/2021, A5E38874562-AC
SITRANS P320/P420