Sealing methods of polyurethane slurry pumps

When it comes to slurry pumps, people are familiar with high-chromium alloy slurry pumps, natural wear-resistant rubber slurry pumps, and ordinary cast iron slurry pumps. Today, we are going to talk about a less common material – polyurethane material for slurry pumps. So, what are the characteristics of this material? And how does its shaft sealing differ from other slurry pumps?

Polyurethane material is a synthetic material made of high-molecular compounds, which has similar properties to rubber, such as good elasticity, abrasion resistance, and corrosion resistance. Compared to rubber, polyurethane has the advantage of good plasticity and higher hardness.

The sealing methods of polyurethane slurry pumps are actually the same as other materials, and they can be divided into three types: packing seal, expeller seal, and mechanical seal. We have explained the characteristics of these three sealing methods in detail before. Today, I will provide a systematic explanation so that everyone can understand them better.

1. Packing Seal: It consists of four packing rings and other small components. The characteristic of this seal is that there may be slight leakage during pump operation, but it is inexpensive, with low maintenance and replacement costs. If the environmental requirements at the site are not particularly high, this sealing method can be chosen.

2. Expeller Seal: It consists of two packing rings, an expeller, and other small components. The characteristics of this seal are similar to the packing seal. There may be slight leakage during pump startup and shutdown, but it is cost-effective with low replacement costs. Unlike the packing seal, it does not require high-pressure shaft seal water but uses grease instead. If adding shaft seal water at the site is inconvenient, this sealing method can be a good choice.

3. Mechanical Seal: It consists of a mechanical seal, a stuffing box, and a shaft sleeve. The characteristic of this seal is that it can achieve completely leak-free operation. However, the price of the mechanical seal is relatively higher compared to packing and expeller seals. If the conveyed liquid is corrosive or if there must be no leakage on-site, this sealing method should be selected.

These are the main sealing methods of polyurethane slurry pumps. If you want to learn more, please feel free to contact us!