Acid & Alkali Rotary Lobe Pumps

Define the Chemical Stream & Operating Conditions

Identify the chemical or mixture, its concentration and measurement basis, and any impurities, process additives, or cleaning fluids reaching the pump. A fluid nickname or pH value alone does not establish material compatibility or the complete pumping duty.

Fluid specification

Identity, concentration, and composition. Provide the process specification and available safety data sheet. Include dissolved salts, suspended solids, and other constituents where known.

Operating window

Startup, running, cleaning, and shutdown. Provide temperature limits, viscosity at temperature, density, flow, pressure, and any change in composition between operating stages.

Wetted Metals & Compatibility Evidence

Review the actual grades of casings, rotors, shafts, liners, and other fluid-contact components against the full composition, concentration, and temperature range. Stainless steel or duplex should not be treated as a universal selection for acids and alkalis.

Request the compatibility basis for the proposed assembly, including cleaning exposure and any abrasive solids. Material charts can support initial screening, but the selected grades and operating limits need confirmation for the actual duty.

Seal Arrangement, Static Seals & Containment

Review mechanical seal faces, O-rings, gaskets, and rotor coverings as distinct components. PTFE, FPM, or another proposed material needs confirmation for its component role, chemical exposure, temperature, and operating conditions rather than selection by family name alone.

Provide the site’s leakage, containment, monitoring, and maintenance requirements. Confirm the proposed seal arrangement and support system against those requirements; a single-seal or isolation-chamber description does not establish the required containment performance.

Crystallization, Shutdown & Restart Conditions

Describe whether the actual fluid crystallizes, deposits solids, or changes viscosity during cooling or time at rest. Provide shutdown duration, temperature changes, and any established flushing, heating, or cleaning procedure for review with the seal and wetted materials.

Assess startup and normal running against the required flow, pressure, inlet conditions, and fluid properties. Confirm pressure protection, seal support, and the handling of leakage or interrupted supply for the selected configuration instead of relying on a general drain or empty-running instruction.