Tamper switch, tamper resistant valve and valve monitor

A method of manufacturing a tamper resistant valve, the method comprising:

• providing a valve housing comprising a valve case and a valve cover, the valve case comprising a base and a wall, the valve cover removable from the valve case and the valve cover defining a housing mechanical linkage or part thereof;
• and
• providing a gear for fitting onto a main valve drive shaft, the gear comprising a valve mechanical linkage or part thereof for inter-fitting with the housing mechanical linkage or part thereof so the valve cover can only be removed when the valve mechanical linkage or part thereof and the housing mechanical linkage or part thereof are in an access orientation and not a secure orientation and wherein the access orientation triggers a switch.

A tamper resistant valve comprising:

• a valve housing comprising a valve case and a valve cover, the valve case comprising a base and a wall, the valve cover removable from the valve case and the valve cover defining a housing mechanical linkage or part thereof;
• and
• a gear for fitting onto a main valve drive shaft, the gear comprising a valve mechanical linkage or part thereof for inter-fitting with the housing mechanical linkage or part thereof so the valve cover can only be removed when the valve mechanical linkage or part thereof and the housing mechanical linkage or part thereof are in an access orientation and not a secure orientation and wherein the access orientation triggers a switch.