Switches proof pressure

Houses located in hazardous areas should comply with the electrical reg lations in force. In some cases, the whole house must be pressurized by using a source of fresh air in non-hazardous areas and an air-sensitive switch to automatically turn off the electrical power if the aeration system should fail. Even if the air is efficiently renewed, explosion-proof switches should be used for aii electrical apparatus. 

When the pressure switch fails dangerously but detected by the effectiveness of the proof test (PSHOl DU E),... 

OR when the pressure switch impulse line fails dangerously and not detected by the proof test (IMP DU U),... 

All components in the system have been individually proofed to 1.5 times then-maximum operating pressure (MOP). All the high- and low-pressure system components have a design burst pressure of at least four times the MOP. The single manifold valve switches the systan from side A to side B so that only one side can be used at a time. This manifold systan was taken from a previously used block that needed the ability to switch from one side to the other. 

Indicating pressure switches provide both pressure indication and the switehing function. Switches installed into areas classified as hazardous, should either be explosion proof or used to switch very low electronic signals within the restraints of code directives. 

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