Your insight is highly appreciated pertaining the installation of pre- action control valve above the suspended falls ceiling, with adequate access. Dose it violate NFPA 13 ?
No, but doing so will make it difficult to inspect and maintain. We have few buildings with concealed control valves, and it's a real bother for monthly valve inspections because we have to haul a ladder around and remove ceiling tiles.
See NFPA 31, 2019 edition
16.1.1 System valves and gauges shall be accessible for operation, inspection tests, and maintenance.
Annex not mentions doors and removable panels can satisfy this requirement.
220.127.116.11.1 Each sprinkler system shall be provided with a listed indicating valve in an accessible location....
Annex note on this says that all control valve should be accessible to authorized persons during emergencies and mentions permanent ladders, chain-operated hand wheels, etc.
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