Siemens SITRANS P500, Operating Instructions Manual, Page: 38 / 238

Install
4.4 Sealing connecting elements
SITRANS P500 with HART
38
Operating Instructions, 12/2014, A5E02344528-09
4.4 Sealing connecting elements
● Siemens optionally delivers a metric thread M20 x 1.5 or a conical thread 1/2-14 NPT for
the cable gland or the blanking plug.
● The metric threads are sealed using O-rings as standard.
● If you are using flat gaskets for a M20 x 1.5 thread, improper mounting can result in
sealing problems.
Instructions for the sealing methods:
Thread sealant
For metric and tapered threads
● To seal the thread, use suitable liquid sealant, e.g. Loctite.
● Completely remove all the sealant residue when resealing the threads following
disassembly.
● Check the thread for possible damage and replace the damaged parts.
● During installation, make sure that the cable gland or the blanking plug is completed
screwed in.
Teflon tape
For tapered thread only
● Make sure that you do not wrap the Teflon tape around threads more than two to three
times.
● We recommend using tape with a thickness of 0.1 mm. If you use thicker tape, you must
reduce the number of wraps.
● Count the threads in the engagement length. Make sure that when you screw in the cable
gland with Teflon tape that the total number of threads has not been reduced by more
than one thread.
Flat gasket
For metric thread only
● Make sure that the flat gasket has a maximum thickness of a thread lead. For example,
the flat gasket for a M20 x 1.5 thread has a maximum thickness of 1.5 mm (0.06").
● Count the threads in the engagement length. Make sure that when you screw in the cable
gland with the flat gasket that the total number of threads has not been reduced by more
than one thread.