Introduction to Steam Distribution

The steam distribution network comprises of pipelines and accessories that connect the steam boiler to the process equipment. The key objective of the distribution network is to transport steam as efficiently as possible, in the required quantity and at the right quality from the steam boiler to the point of use in the process. In practical settings, plants face several issues due to deficiencies in the distribution network.

 

IssuesPossible Causes
Pressure drop or steam starvationUndersized steam lines
Frequent leakages from flanges,
gasket failures or pipeline leakages
Condensate accumulation in the lines on account of
– Wet steam
– Necessary pipeline slope not provided
– Incorrect drain pockets
– Sagging of the pipelines due to incorrect/ inadequate supports
– Steam traps not installed at desired locations
– Water logged /blocked /isolated mainline traps
Displacement of the pipelines– Incorrect/no provision for pipeline expansions
– Incorrect piping supports
Higher batch times in the processPresence of air / air-steam mixture in the system
7-10% gap between steam generation and consumption / unaccounted distribution loss– High radiation losses
– Leaking steam traps
– Direct steam leaks

Table: Common issues in steam distribution and their possible causes

These issues adversely impact the plant’s performance on Product Quality, Productivity, Energy Conservation, Safety, Uptime and Sustainability.

Optimising the distribution network involves addressing four key aspects:

  • Supplying the right quantity of steam to the process
  • Ensuring steam quality i.e. the steam is dry, clean and free from air
  • Ensuring that the distribution losses do not exceed 3% of steam generation
  • Making sure that the network is safe and easy to operate and maintain