Valve type and principle-steam-blocking drain valves

(1) Bell-shaped float trap

Mainly composed of regulating valve, bucket, outer casing and filter device.The bucket inside the trap is inverted, initially in the lowered position, and the regulating valve is open.When the cold air and condensate in the equipment or pipeline enter the trap under the pressure of the steam, they are discharged by the regulating valve.On the one hand, when steam and air gradually fill the internal volume of the bucket, and the condensed water accumulates continuously, the bucket rises due to buoyancy, the regulating valve closes, and the discharge of condensed water stops;On the other hand, a small part of the steam and air inside the bucket is discharged from the small hole at the top of the bucket, and most of the heat is condensed into a liquid, so that the buoyancy of the bucket gradually decreases and falls, so that the regulating valve is opened and the condensed water is discharged.

(2) Thermodynamic steam trap

When the condensate in the equipment or pipeline flows into the choke drain valve, the steam in the transformer chamber is condensed to reduce the pressure, and the force under the valve plate is greater than the above force, so the valve plate is lifted up.Because condensate is more viscous than steam and has a low flow rate, it is not easy to cause negative pressure between the valve plate and the valve bottom.At the same time, the condensed water does not easily flow into the pressure changing chamber through the gap between the valve plate and the outer casing, so that the valve plate is kept open, and the condensed water flows through the annular groove.

When the steam in the equipment or pipeline flows into the trap, since the viscosity of the steam is smaller than the condensed water and the flow rate is high, the valve and the valve seat are likely to cause a negative pressure.At the same time, part of the steam flows into the pressure changing chamber, so that the force on the valve plate is greater than the force applied below, so that the valve plate is quickly closed.This works periodically, which automatically discharges the condensate and prevents the steam from escaping.