Use of Utility Station

Utility Stations are required for operations and maintenance. They are not optional they are mandatory, just ask the Client.

A “Utility Station” is a place in a Process Plant (Refinery, Petrochemical Plant, Chemical Plant, Power Plant, etc.) where utility services are provided for the use by Plant Operators and Maintenance people. These “Utilities” will normally include: Plant Water, (Low Pressure) Steam and Plant Air. Some Clients also require Nitrogen.
The “Plant Water” is for wash down of water soluble spills.
The “Steam” is for wash-down of hydrocarbon fluids.
The “Plant Air” is for pneumatic power tools.
The “Nitrogen” is for purging fluids and gasses from pipe systems prior to maintenance work.

A “full” (all services) utility station for the normal grade level location. Other utility stations are also required for elevated locations such as on the upper levels of structures and Vertical Vessels. Elevated Utility Stations may be “Full” Stations or may be limited to just one (Air) or two (Air & Steam) services depending on the requirements in the Clients Project Design Specifications.

What is the necessity of placing the steam line for the utility station on the top platform of the columns?
Is it really necessary?
If yes, when and how it will be?

My answer:
This is a very common situation.
The reason for the Utility Steam (and Utility Air) at the top platform is for maintenance requirements.
The situation would be:
- A very tall vessel
- In a dirty service
- When the vessel is subject to higher than normal maintenance activity
- The relative low cost of the pipe material is less than the labor hour costs to drag hoses from grade to the top of the same vessel plus the cost of that hose.
- When the Client's Maintenance Department says that they want it

if the answer to all or most of these is "Yes" then you should do it.

The way I did it in the past was:
- Run two 3/4" (DN 20) lines from the bottom of the column to the top platform.
- the lines would start about 4'-0" (3.2M) from grade
- They would end about 3'-0" (1M) above the top platform
- The lines would be supported near the top tangent line of the vessel
- the lines would be guided about every 20'-0"
- at the bottom of each line there would be the appropriate hose coupling for the service and a sign defining the service
- At the top of each line there would be a line class block valve, a nipple, an elbow, a nipple, the appropriate coupling for the service and a sign defining the service
- the steal line would not be insulated unless it is required for personnel protection at platforms. The steam in the pipe is going to be "thrown away" so there is no logical reason for conserving it.

When maintenance is required at the top of the vessel then a hose is run from a Utility Station at grade to the connections at the bottom of the tower. Additional hosed are lifted to the top of the vessel for use there.

Options: additional outlets could be added at intermediate platforms where Utility Air and Utility Steam might be required.

The First criteria is Safety. Once a sequence is established for a plant make sure that ALL of the Utility Stations are the same. It would not be good for you (being a maintenance person who just wanted to wash your hands) to turn on a valve thinking it is Utility Water and get scalded by Utility Steam.

The criteria for the sequence is the preference of the Plant Operators and Maintenance people.

SWAN is S (Steam), W (Water), A (Air) and N (Nitrogen). Not a bad sequence to follow.

Safety First