Steam Traps Flashcards
What’s a steam trap?
-Self contained valve that automatically drains condensate from a steam system
Why do we use steam traps?
-To prevent water hammer
What’s water hammer?
- Sudden, intense,pressure surge or wave in a fluid or vapor system
Three types of steam traps at PVGS
-mechanical (free float,inverted bucket )
-thermodynamic (Disc trap)
-thermostatic (balanced pressure)
Two types of mechanical traps
-Free float
-float lever
How does an inverted bucket work?
-Upside down bucket inside a container
-Valve opens/closes as bucket floats/sinks
-If steam fills the bucket it becomes buoyant closing the trap
-Vice versa when condensate enters the bucket falls and allows condensate to flow
What type of thermostatic steam trap does PVGS use?
-PVGS uses balanced pressure (bellows that work off temp.)
How does a balanced pressure trap work?
-Bellows pressurize/depressurize in response to temperature which open and closes the trap.
Types of operations Balanced pressure traps mainly used for?
-System startups where large volumes of purging is required
What type of thermodynamic steam trap do we use?
-PVGS uses disc trap thermodynamic steam trap
How does a disc trap work?
-Disc traps work off surface area, As steam enters the trap it applies more pressure on the top then water can at the bottom and closes the disc
-as condensate enters it cools the steam allowing the condensate to pass
How are steam traps identified on P&ID’s?
-Identified in a box with several valve numbers inside
How do you find the details of the steam trap?
-You find the details in the mech. Legend P&ID using the trap detail
What can be done if the trap isn’t functioning properly?
-Operate the manual bypass valve
What are critical steam traps?
-traps that if removed from service need an alternate means of steam traping or the piping needs to be removed
