No, according to the definition in Article 2 (4), a safety accessory is designed to protect pressure equipment against exceeding the allowable limits.
Note 1:
However, there are important safety implications for these devices which are covered by the essential safety requirement Annex I Section 2.3 of the PED.
The manufacturer shall address this as part of the hazard analysis.
Note 2:
This control equipment could be of a simple self-acting type or of a more complicated type, e.g. with a pressure transmitter and an actuator.