Pump Selection Guide for Benzene-Containing Wastewater

I. Three Core Selection Requirements

Benzene-containing wastewater is highly toxic, volatile, flammable, explosive and corrosive to organic solvents. Pump selection must comply with three mandatory standards:

1.Zero leakage

Volatilized benzene vapor may lead to operator poisoning and form explosive gas mixtures. Pumps shall adopt fully sealed seal-less construction, and pumps with packing seal or ordinary mechanical seal are forbidden.

2.Resistance against organic solvent corrosion

• 316L stainless steel: for low and medium concentration benzene wastewater
• Fluoroplastic: for high-concentration strongly corrosive benzene wastewater
• Silicon carbide: bearing material for wastewater with fine solid impurities
• Fluororubber / PTFE: dedicated anti-corrosion sealing parts

3.Explosion-proof and anti-static performance

Motors shall meet ExdII BT4 and ExdII CT4 explosion-proof grades. Both pump body and complete electrical control system need full explosion-proof design to avoid explosion caused by electric spark or static accumulation.

II. Preferred Pump: Magnetic Drive Pump

The optimal option for continuous production. Adopting magnetic coupling seal-less structure to achieve full zero leakage, customizable anti-corrosion materials and optional full explosion-proof configuration. It avoids frequent seal replacement, reduces maintenance cost and supports 24-hour uninterrupted continuous operation.

III. Two Alternative Pump Types

1.Pneumatic Diaphragm Pump

Powered by compressed air without electric components, inherently explosion-proof and applicable for wastewater with sediment and impurities. Limited to intermittent feeding and short-distance transportation only.

2.Explosion-proof Chemical Centrifugal Pump

Features large flow and high head, mainly used for centralized transportation in large sewage treatment plants. Equipped with mechanical seal which bears leakage risk after long-term operation and requires regular inspection and part replacement.

IV. Prohibited Pump Types

Ordinary clean water centrifugal pump, screw pump, vane pump and conventional self-priming pump. These pumps have poor sealing performance and non-resistant materials against benzene solvent, prone to leakage and corrosion failure with potential safety and environmental risks.

V. Practical Selection Tips

1. Magnetic drive pump is prioritized for enclosed workshop and continuous production conditions;
2. Material selection based on wastewater concentration: 316L stainless steel for low/medium concentration, fluoroplastic for high concentration, silicon carbide bearing for impurity-containing medium;
3. Complete explosion-proof configuration for pump, motor and control system as a whole.

Summary

Continuous stable transportation: Explosion-proof magnetic drive pump

Intermittent temporary feeding: Pneumatic diaphragm pump

Large-flow long-distance transportation: Explosion-proof chemical centrifugal pump

Omron Tech Pumps’s explosion-proof magnetic drive pumps are manufactured in strict accordance with above standards, widely applied in chemical, environmental protection and petrochemical industries.