Automatic Pumping Trap

FORBES Marshall brings to you the Automatic Pumping Trap - the world's smallest condensate drainage system that works under all the load conditions, even vacuum. It's compact design makes it convenient to install within 200 mm of the installation head. The Automatic Pumping Trap is fully mechanical with no requirement for electrical power, pnuematic supply, motors or level switches. 
What do you mean by Stall ? 
Stall is the reduction or the cessation of condensate flow from the steam space, and occurs when the pressure in the steam space is equal to, or less than, the total backpressure imposed on the steam trap.