Replacement of the negative pressure pump
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Currently, a negative pressure centrifugal pump is being used, with an operating pressure of -0.093 MPa. The fluids handled are DMF and toluene; the pump body is made of 304 material, and the operating temperature ranges from 50 to 80°C. These conditions result in high corrosion levels. Mechanical seals and pump end cover seals are replaced frequently. Are there any other pumps that can be used as a replacement while maintaining the current operating conditions? Good quality at a low price is the top priority.
High quality at a low price – it’s probably hard to find, huh
The price is roughly the same as that of negative pressure centrifugal pumps; if it’s more expensive, the customer won’t bear the extra cost.
Pumps also follow the rule that you get what you pay for :)
Meet the operational requirements, and then check whether the cost-performance ratio is appropriate
First, find out what’s causing the problem: corrosion, cavitation, wear. If we don’t know the cause, then whatever we replace will be purely by luck
Corrodes mechanical seals and pump end cover sealing rings. DMF is too corrosive!
If it’s just the sealing ring that can’t withstand the medium, there’s no problem with the metal material; one can use PTFE, FFKM perfluoroether, or flexible graphite seals, or consult manufacturers specialized in sealing materials. Ideally, the user or owner should know what type of seal is appropriate for this application, as reference information is available in the equipment documentation when purchasing the process package
I checked the data from manufacturers of sealing materials; in theory, EPDM can also be used. PTFE gaskets, FFKM rubber rings, or seals coated with PTFE are all viable options. As I recall, the pumps used in my company for this type of application previously used either PTFE or FFKM as sealing materials. FFKM is relatively expensive – a single ring can cost several thousand dollars
This post was last edited by Zhongheng Pump Industry on 2021-7-9 at 17:07. Hello, original poster! The centrifugal pump you have chosen can operate properly under this negative pressure; however, if the mechanical seal and the pump end cover seals need to be replaced frequently, it might be advisable to use a magnetic coupling first (which provides zero leakage and does not disrupt the vacuum). You just need to regularly check whether the centrifugal bushings are worn out. I hope this can help you. If you have any issues related to pumps, feel free to leave a message or contact us by phone at 13313170275 (Zhongheng Pump Industry)