Process Plant Utilities Terminology

Process Plant Utilities Terminology

The utility is a refinery’s service portion. While a home has water, gas and electricity, a refinery or other plant has many more, some of which are below.


Steam services many plant items. Heat generates steam in fired boilers or heater which will make many different steam pressures and temperatures. They apply heat and convert condensate (pure water) to steam (a vapor). The steam then goes to the different plant units in the piping systems which use the steam.

Many students think they have seen steam, but they haven’t. They cannot actually see steam: it is invisible. What they have seen is the condensate condensing out of the steam. That is where the term condensate” comes from.


As the energy in steam is used, the steam turns to condensate. Another piping system collects this condensate, which is returned under a row pressure to a collection point and is pumped through the boiler tubing and converted to steam again. So the condensate is in a constant cycle from steam to condensate to steam.

Fuel Oil

Fuel oil is another utility that refineries make and partially consume. It is also sold as a product to heat homes and fires furnaces in private business.

Instrument Air

A utility that operates the plant instruments is instrument air. A piping system distributes this air, which has been compressed and dried to remove, all its moisture, as the moisture would harm the instruments.

Utility Air

Utility air drives air motors and blow air on objects to clean them, such as some barbers blow cut hair off customers with air hoses.

Cooling Water

Cooling water cool various streams in a plant. The water starts at a cooling tower and is pumped through a piping system to exchangers, which exchange heat. it comes out boner-much like water from a hot water heater in a home. This water then returns to the cooling tower, which cools the water. and then is ready for more circulation into the unit. Like the steam and condensate system above, this is a constantly c system.


An underground utility collects drains from funnels or catch basins and, in a separate piping system, transports them to a disposal point. Since no pressure is in this drain piping, the pipes must slope to cause flow. This slope is usually 1 foot per 100 feet of tine or greater.

It can be very difficult to design drain systems. Since they run underground, they must miss all other underground items. The drainage system must twist and turn to miss all the process equipment foundations.
Most plants also have more than one drain system. They may have an oily water sewer a storm water sewer and an acid sewer.

The oily water sewer handles the oily drips and drains. The storm water sewer collects surface runoffs from rains. The acid sewer collects acid drains and drips. There may be many other types of separate drain systems.

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