Is this sentence correct?

Is this sentence correct?: " If a document is to be reviewed by more than one department, preferably only a single copy of the document should be circulated.
I don't understand if... is to be reviewed what is it grammatically? it is conditional, but is it correct like this?

Thanks Smudla

[Francois]

Yes, it's fine.
You can take a look here.

FRC

Not only is it fine (Francois), it is correct.

The subject of the sentence (document) is a singular noun therefore the verb of the sentence (to be) must also be singular.