When natural gas is subject to pressure reduction, the temperature is subject to a reduction as well. It is a normal practice to have provision for heating natural gas, preferebly befeore the pressure reduction stage, so that its temperature is maintained at an acceptable level to avoid operational and material integrity problems that can be caused by low gas temperature. Design can have several options both on bundle and on control side, such as:

– number of bundles series/parallel
– isolation and redundancy among bundles
– safety control for electrical spark, temperature control, pressure and flow switch
– type of tempertaure control (spet, continuos or combined)

It is the inlet section and it provides the closure of the flow in case of an emergency. It can be remote/manually operated with different possibility for the re-opening and re-pressurizzation of the downstream lines. Usually composed of a small skid mounted unit with one actuated ball valves next to a manual gear operated one.

Filtration is one of the most crucial aspect of natural gas system. It can be composed of several stage.
The first stage can the Knock Out (KO) Drums. It is used when considerable quantities of fluid, like water or hydrocarbon condensates is expected with the natural gas. , a knock-out drum with a demister can be installed. Placed after the ESD skid it is used as a single filter to remove the most heavy particles inside the gas.
The second stage is the main filtration point and it can be customized according to the design conditions and installation constrains. Main options are:

– Single stage/ double stage
– Vertical/ horizontal
– Manual/ automatic drain into condensate tank

The third and last stage is the final filtration. It is the last barrier before the burner or GT. The configuration is usually a single stage filter of coalescing cartridges with efficiency of 99,9% for particles up to 3 micron or better.

Gas pressure reduction installations help to control and regulate the flows of gas to ensure the effective and efficient operation and for downstream protection by means of control valve system.
Number and type of installed safety devives depend to customer request and local regulations.
Can be combined flow & pressure reduction and control.
Can be of one or two reduction stages.

Dosing Scale Inhibitor for controlling conductivity to prevent scaling. Controlling pH by metering acids and caustics to maintain a pH range that prevents corrosion. Controlling ORP by metering bromine or chlorine to prevent biological growth and fouling. Metering inhibitors such as polyphosphates to inhibit corrosion. Timed dispensing of biocides such as gluteraldehyde or isothiazilone to prevent biological growth and fouling. Even some of the ordinary treating chemicals, such as chlorine, are themselves corrosive, frequently attacking the wooden surfaces of the cooling tower, causing delignification of the wooden structure.  Addition of MgSO4 can prevent the deterioration of wood structures of cooling towers and prolong.

Heating of water will form CO2 and oxygen, which forms carbonic acid when it condensates. This can cause the boiler to corrode.  Neutralization is carried out injection Alkalis. To prevent Corrosion and pitting of boiler tubes hydrazine or oxygen scavenger chemicals injection(LP Dosing) is being used. High pressure dosing Tri sodium phosphate injection into boiler is added to reduce Scale formation into boiler. Tri sodium phosphate act as Scale Inhibitor. To prevent corrosion of boiler internals, amine injection is used to coat the inside of the boiler. Sodium Bisulphate is used as Oxygen scavenger.

Coal and gas power plants emit Sulfur Dioxides(SO2), Nitrogen Dioxides (NO2), Carbon Monoxides (CO), Particulate Matter. Wet Scrubbing method is used to desulfurize flue gases. Scrubbing agent includes injection of calcium carbonate and caustic soda (sodium hydroxide). Ammonia can be added to the flue gas in the stack to reduce the particulate matter discharged in the process of burning coal.