Flameproof Class 1, Div 1 Compliance

The prototype device will need to be type-tested at an accredited testing laboratory before a certificate can be issued.

BASEEFA is the UK-based agency that does this (usual disclaimer).

I understand that the slot is cut in aluminium plate to insert electric heater and this heater if part of either process vessel or any other process equipment handling hazardous chemical. Normally process equipment are provided with nozzle to insert heater. The heater to be inserted are certified for use in area classification. The arrangement being described is very crude method and should not be attempted because of 1. The plate is being used for screwing which does not indicate the meeting surface of the flange required for cooling down of explosion before it comes out from the flange. 2. The sealing after inserting heater is also very crude method. Normally cables are connected through cable glands. In case conduit entry is used, these are also threaded as per NPT. if the product is for development stage, kindly refer codes for enclosure of explosion proof equipment as these will require testing and approval for compliance to codes.