Steam trap flange is simple in structure, only one moving part within the fine grinding of stainless steel hollow float; it is opening and closing parts, no wearing parts, long service life. Steam trap flange operates on the principle that hot water under pressure tends to flash into steam when the pressure is reduced. So that you under-stand how this principle is used, let’s consider the arrangement of parts shown in figure 13-35 and see what happens to the flow of condensate under various conditions.
Steam trap flange runs through the disk from top to bottom and is considerably smaller at the top than at the bottom. The bottom part of the disk extends through and beyond the orifice in the seat. The upper part of the disk (including the flange) is inside a cylinder. The cylinder tapers inward, so the amount of clearance between the flange and the cylinder varies according to the position of the valve. When the valve is open, the clearance is greater than when the valve is closed.
When the trap is first cut in (put in service), pressure from the inlet (chamber A) acts against the underside of the flange and lifts the disk off the valve seat. Condensate is thus allowed to pass out through the orifice in the seat. At the same time, a small amount of condensate (CONTROL FLOW) flows up past the flange and into chamber B. The control flow discharges through the control orifice, into the outlet side of the trap. All in all, Steam trap flange is widely used in many fields.