According to Indian Boiler Regulations the essential requirement of any safety valve is that

• A. It should be costly
• B. It should have good appearance
• C. Its area should be sufficient to discharge the steam as quickly as it is generated with rise in pressure not more than 10% of the safety valve blow off pressure
• D. It should be located outside the boiler room
• E. It should be visible to boiler operator from all positions in the boiler room