FILTERS & STRAINERS - STEAM TRAPS PDF Print E-mail
Written by Norrie   
Tuesday, 11 May 2010 19:22
Article Index
FILTERS & STRAINERS
FILTERS
STRAINERS
STEAM TRAPS
MECHANICAL STEAM TRAP
THERMOSTATIC STEAM TRAP
THERMO-DYNAMIC STEAM TRAP
EJECTOR SYSTEMS - INTRODUCTION
EJECTORS AND EDUCTORS
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3. STEAM TRAPS

In operations involving the use of steam for heating process fluids in exchangers, vaporizers, reboilers … etc, much of the steam condenses back to water as it gives up its latent heat to the process fluids. The water, if allowed to remain in the system, would cause problems leading to loss of efficiency and would cause 'Water Hammer' in the piping.

Water hammer is caused when water in steam pipes is allowed to build up. The steam travelling at high velocity pushes slugs of water along the pipe until it slams up against a bend or fitting in the system. The force of the water striking the bend causes a noise like a hammer blow and, at the same time the force of the impact produces a heavy shaking and vibration of the pipe-work. The power of this hammering can result in damage to piping and equipment. The slugs of water in the piping also cause 'steam-lock' in the system giving rise to pressure surges as steam flow is temporarily blocked. Another effect, is the rapid condensation of steam and re-vaporization of water which also causes pressure surges within the system.

The only way to prevent water problems in steam systems is to ensure that the water is continuously drained away. To have an operator standing by each steam system to drain off water would be very uneconomical and a waste of manpower.

To deal with the problem, 'STEAM TRAPS' are installed at strategic points in a steam system. The steam traps are automatic in operation and, when properly maintained will perform the job of water removal continuously and efficiently.

There are various types of steam trap. The main types are listed and explained as follows :

  1. MECHANICAL TRAP
  2. THERMOSTATIC TYPE
  3. THERMO-DYNAMIC TYPE