What causes the inward deformation of the rubber flexible joint at the pump inlet?

The negative pressure at the pump inlet increases, causing the rubber flexible joint to deform inward

It may be that the rubber flexible joint itself does not have sufficient strength, or the negative pressure is too high (such as a clogged filter or a pipe with an excessively small diameter).

The filter is clogged, the hose is not strong enough, and the pipe diameter is too small

Yes, it’s possible that it was deflated by negative pressure. It’s also possible that the rubber wall is too thin

1. The closer the pump inlet pipe is to the impeller, the lower the pressure there becomes, eventually reaching negative pressure. 2. Under positive pressure conditions, it is the strength that determines the pressure-bearing capacity of the pipe； Stiffness is what is used to evaluate the resistance to deformation under negative pressure. 3. Under normal circumstances, when selecting non-metallic pipe fittings, designers take into account their pressure-bearing capacity to ensure that the fittings do not rupture and cause problems; therefore, the strength of such fittings is sufficient. 4. However, manufacturing units of non-metallic pipe fittings do not establish any specific criteria regarding the ability to resist deformation under negative pressure and maintain the shape within an acceptable range; therefore, there is no basis for making selection decisions in this regard. 5. One of the main factors causing inward bending under negative pressure during operation is increased wall thickness, or the use of internal rigid supports, which are effective solutions. 6. On the other hand, when significant inward deformation occurs, it serves as a reminder to the user to investigate the causes of the increased negative pressure and address them