Can multi-stage centrifugal pumps be purged with steam?
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Can multi-stage centrifugal pumps be purged with steam? Please give me some advice! What should be noted? This post was last edited by Ma Hai on 2009-3-30 16:39.]
No. Why use steam purging?
Pipelines can be purged, but pumps cannot; they must be removed first before being cleaned.
No, it is caused by severe temperature changes, which lead to different rates of contraction of the bearing shell and thus result in damage
The designer can perform purging as long as a steam purge line is provided after the pump inlet valve. Otherwise, it can’t be blown.
“Whether blowing is possible depends on the circumstances; as long as the designer provides a steam purge line behind the pump inlet valve, purging is feasible. Otherwise, it can’t be blown. ” Can’t it be done like this? If you give it, you can blow; if not, you can’t. There’s always some reason given, right?
For sulfur plants, it is more appropriate to deliver the lean and rich liquid pumps as well as the acid water pumps for maintenance after flushing them with water. If steam is used for purging, it may damage the pump. Additionally, when draining the liquid containing hydrogen sulfide from the pump, the liquid is discharged into a sealed container; using steam for purging means that these high-temperature gases enter these sealed containers, resulting in problems related to high temperature and overpressure. For refining units, light oil pumps can be delivered for maintenance with the liquid flowing out cleanly on its own through natural pressure relief, without the need for purge steam. Heavy oil pumps must be purged; otherwise, when it is time to relieve pressure and drain the liquid at the safe temperature, the high viscosity of the oil prevents it from flowing out at all. If it is delivered for maintenance in this condition, the pump interior, the inlet pipelines, and the outlet pipelines will all be filled with heavy oil (as in the case of sludge pumps); even though the impeller part can be cleaned, what about the inlet and outlet pipelines? How to clean it? After the pump has been overhauled, since both the inlet and outlet pipelines contain cooled heavy oil (which may turn into solid masses if it is reduced-pressure oil), how can they be preheated for use? It can only be delivered for maintenance after being cleaned with steam. After the maintenance is completed, the outlet valve and pre-heating line valve, as well as the inlet valve, must be opened for the oil to flow and thus enable pre-heating for standby use.
I also noticed this problem today, and I think it’s quite serious! Our pump steam purge is located behind the pump inlet valve; if purging is not possible, is it clearly a design issue? Generally, steam purging can cause significant damage to pumps, and the steam temperature accelerates the aging of the O-rings inside the pump. So I decided to have the construction team install the steam purging pipeline in front of the inlet valve
Under normal circumstances, centrifugal pumps must not be purged with steam!
It depends on whether it is a high-temperature pump or a low-temperature pump: those operating below 200°C are considered low-temperature pumps, while those at 200°C or above are high-temperature pumps. High-temperature pumps can be purged with steam, whereas low-temperature pumps cannot.
Why? Could you make it clearer?