9
Task and function
Purpose
The equipment is designed for discharging large
condensate flowrates that are produced
continuously and for air-venting pipelines.
The equipment opens and closes as a function of
the membrane regulator (thermostatic capsules)
immediately below the pressure-dependent
saturation temperature.
At start-up and during operation the equipment
automatically vents non-condensable gases.
Function (equipment with DN 50)
The membrane regulator capsules and the
upstream pressure of the condensate control the
discharge of condensate.
If undercooled or cold condensate, or air or other
incondensable gases are present, the membrane
regulator capsules are in the open position.
The pressure in the chamber (18) drops below the
upstream pressure and, as a consequence, the
regulator unit is lifted and the valve (20) opens.
The condensate or the gas is discharged.
A small part of the fluid ("leak passage") flows
through the regulator unit with the membrane
regulator capsules. This partial flow enters the
chamber through the annular slot (17) and flows
through the regulator unit and the cone (19) before
it is discharged.
This ensures that the membrane regulator capsules
always have the same temperature as the fluid.
Immediately before the boiling temperature of water
is reached the membrane regulator capsules are
back in the closed position.
The partial flow can no longer drain. Inside the
chamber pressure builts up until it reaches the
upstream pressure of the fluid and the valve is
closed.
The lift plate (21) prevents the steam trap from
opening and closing abruptly.
