The seal of the high-pressure lean amine liquid pump PLAN52 is in use; the level of the seal oil tank has risen to its full capacity, the pressure is 0.005 MPa, and the temperature of the return seal oil is 55°C. Please analyze the reasons and provide a conclusion – can the mechanical seal continue to operate?
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The seal of the high-pressure lean-ammonia liquid pump PLAN52 shows that, after operating for a certain period of time, the liquid level in the seal oil tank rises to the full level; the pressure is 0.005 MPa, and the temperature of the return seal oil is 55°C. There is no external leakage from the mechanical seal. Please analyze the reasons and provide a conclusion regarding whether the mechanical seal can continue to operate
Medium measurement: seal leakage detected! Replacement and maintenance!
Then why doesn’t the pressure rise in the case of a medium seal leak?
Since it’s the 52 scheme, it involves a pressure-free buffer tank connected in series with a mechanical seal. The value of 0.005 MPa – in our industry we usually say that 1 MPa is equivalent to 10 kilograms of pressure; so 0.005 MPa is practically zero pressure. With this 52 scheme, the level of liquid in the buffer tank is monitored; if the medium leaks into the seal oil, it will then flow into the buffer tank. If you don’t believe it, you can drain the oil from the buffer tank and check for yourself.
How long for a while? Exactly how long? In the pump area for aromatic reformation here, a large number of seals of type PLAN52 are in use. In a few units, the liquid level in the storage tank rose to the alarm threshold after about half a month. What I did was to temporarily drain some of the liquid from the bottom of the seal tank and then monitor the situation; if the rate of rise continued to be fast, I would arrange for repairs at an appropriate time. Your amine liquid pump is more or less exposed to H2S, so it’s advisable to arrange for the repair of the spare parts at an appropriate time.
52 leaked into the white oil tank, so the liquid level rose; as for 53, it is a white oil tank under pressure, and if there is a leak the liquid level drops (as fluid leaks into the surrounding medium)
The mechanical seal, as detected by the medium sensor, is leaking. It is recommended to first drain some of the liquid level to bring it down to an intermediate level in order to observe the rate at which it rises, and to prepare for maintenance work. If the liquid level rises too quickly – to the point where drainage is necessary on a daily basis – then maintenance should be carried out at an appropriate time. If the rise is slow, then it’s sufficient to continue monitoring its operation
It’s flowing into the vent line… The flushing at 52 leaks as soon as the liquid level rises
Since the leakage at the medium side seal is not severe, the pressure balance on both sides prevents further leakage from the medium side seal