Question regarding the pressure behind the steam trap, urgent
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How is the pressure behind the steam trap determined? For example, I have a steam stream at 0.4 Mpa, and the condensate downstream of the steam trap is discharged directly on-site; in other words, the pressure downstream of the steam trap is at atmospheric pressure. Similarly, there is another steam stream at 0.8 Mpa, with the condensate downstream of its steam trap also being discharged directly on-site. In that case, can the pipelines downstream of the steam traps for these two steam streams be combined?
Those with similar back pressure can be combined; for those with a large difference, the one with lower back pressure cannot be discharged.
So, how is the back pressure determined? Can the back pressure of the check valve be set to be the same?
The drainage capacity of a steam trap is related to the pressure difference; the greater the pressure difference, the more water can be drained. In other words, if the designed pressure difference is too low, it becomes necessary to use a larger steam trap, which is not cost-effective； And if closed-loop recovery of condensate water is used, a large design pressure difference will affect the subsequent transportation of the condensate water; it’s sufficient to determine one based on the subsequent process steps
The back pressure is determined during the process design; in other words, the inlet pressure, back pressure, and amount of water to be drained determine the selection of the steam trap. By checking the specifications of the steam trap, one can determine the approximate range of back pressure.
This depends on the pressure drop in the condensate pipeline behind the trap, as well as whether the trap is carrying too much steam, or if the exhaust temperature is too high, resulting in severe vaporization after the pressure is reduced When 0.4MPa and 0.8MPa steam tracing drains meet at a drain station manifold, we have this situation. There are even 3 heat-traced drains for 3.5MPa steam connected to them as well. But we also sometimes encounter problems in this regard; in such cases, it is sufficient to find a strainer with a large drainage capacity and lower its drainage temperature to resolve the issue (most of the strainers we use nowadays are bimetallic ones, with adjustable drainage temperatures).
I have already expressed my opinion on this issue; theoretically, those with the same back pressure can be connected to a single return pipe. However, two issues need to be noted: one is the piping problem, and the other is selecting a proper steam trap. As the person upstairs said, people turn to steam traps with a large discharge capacity when there are problems; it sounds easy in theory, but in practice it’s quite troublesome – checking dozens or hundreds of steam traps one by one is a time-consuming task. The venturi-type steam traps we produce require no replacement or maintenance for 10 years, and have a low leakage rate. Not affected by back pressure. It can **reduce costs related to on-site inspection, maintenance, replacement, etc.**
Will severe vaporization occur after the steam trap when the exhaust temperature is too high? For the subsequent gas-liquid two-phase flow pipeline, what values should be used for the flow rate and pressure drop?