Yes, provided the « pi » marked receptacle has been placed on the market and used as transportable pressure equipment, it can then be used permanently as static pressure equipment without being CE marked.
Note 1:
For static use the receptacle may be subject to national regulation dealing with conditions of use, installation and periodic inspection. (see also Article 3 of TPED 2010/35/EU- On-site requirements)
Note 2:
The term “static pressure equipment” has to be understood as “pressure equipment under the scope of Pressure Equipment Directive”, even though these receptacles fall under Article 1 paragraph 2 (s) of PED.
Note 3:
See PED Guideline A-30 for receptacles with double CE-mark and π-mark.