Section 78. The owner or user of a boiler required by section seventy to be inspected shall prepare the boiler for inspection as directed by the inspector. The inspector shall, if requested, give the owner or user at least fourteen days notice to prepare a boiler for inspection; provided, that no notice shall be required of an external inspection, nor if the boiler is being installed or has not been inspected within one year and a certificate of inspection issued. If, in the judgment of an inspector of the division, any such boiler or its appurtenances is in a defective or dangerous condition, he may immediately forbid the operation of the boiler, whether or not it is under the inspection of an insurance company; and no person shall again operate such boiler nor cause it to be operated until a certificate of inspection has been issued by an inspector of the division. The owner or user of any boiler required by section seventy to be inspected shall immediately notify the division of inspection or the insurance company, if a boiler is insured, if a defect affecting the safety of the boiler is discovered. If the insurance on any boiler required by section seventy to be inspected expires, or is cancelled because the insurers deemed it unsafe to continue the operation thereof, the owner or user shall cease to operate it until it has been put in a safe condition, satisfactory to the insurers, or has been inspected by the division and a certificate of inspection has been issued.