What are the important control valves on the nitric acid plant?

Important control valves on the nitric acid production plant are as follows:

**I. Process section**
| Serial No. | Name of Control Valve | Medium |
|-------------|------------------------|--------|
| 1 | Ammonia evaporator liquid level control valve | Ammonia |
| 2 | Ammonia pressure control valve at the outlet of the ammonia evaporator | Steam |
| 3 | Ammonia gas temperature control valve | Steam |
| 4 | Ammonia gas flow control valve | Ammonia gas |
| 5 | Ammonia gas vent valve | Ammonia gas |
| 6 | Ammonia gas shut-off valve | Ammonia gas |
| 7 | Boiler feedwater temperature control valve | Steam |
| 8 | Bubble column liquid level control valve | Water |
| 9 | Absorption tower liquid level control valve | Nitric acid |
| 10 | Bleaching tower liquid level control valve | Nitric acid |
| 11 | Water supply flow control valve at the top of the absorption tower | Water |
| 12 | Steam condenser liquid level control valve | Condensate |

**II. Unit section**
| Serial No. | Name of Control Valve | Medium |
|-------------|------------------------|--------|
| 1 | Air compressor outlet anti-surge control valve | Air |
| 2 | Exhaust turbine cooling air control valve | Air |
| 3 | Exhaust turbine inlet valve | Exhaust gas |
| 4 | Exhaust turbine bypass valve | Exhaust gas |
| 5 | Secondary air control valve | Exhaust gas |
| 6 | Steam turbine speed control valve | Steam |