It shall be unlawful for any person not connected with the commissioners of public works of any municipality of this State, the fire department of any such municipality or the body charged with the duties of commissioners of public works in municipalities which have no such commissioners to interfere with or open for any purpose whatever any of the fire hydrants on the mains of the waterworks of such municipalities, except in case of fire, without first having obtained a proper permit so to do from the authorized representatives of such commissioners, fire department or other such body.