Read paragraph 4 of the attached document.
Thanks,
Dzyanis.
https://fluidpower.prohttps://files.engineering.com/getfile.aspx?folder=c1561470-00c8-4fd0-9a22-f34bfe7aa6a0&file=TI001-1.pdf
Check valve pilot operated with manual override.
This symbol doesn't match ISO 1219 but I often meet it at the drawings.
Thanks,
Dzyanis.
https://fluidpower.pro