Wilden AODD Pumps for Chemical Process Applications

Wilden Chemical Process

• Can I mix several chemicals in one AODD pump based on chemical resistance charts?

  Proceed with caution. Wilden chemical transfer pumps are not recommended for blending multiple chemicals without a prior chemical compatibility review. Individual ratings may or may not apply to a chemical cocktail. You should never use the pump to mix the chemicals together, as a chemical reaction can occur in the pump, potentially causing thermal or chemical hazards and resulting in catastrophic failure.

• How do I choose the best diaphragm pump materials for chemical compatibility?

  Wilden recommends consulting resistance charts to select the appropriate diaphragm pump materials for chemical process applications.

  • Selecting Pump Housing Materials: The initial step is to confirm the chemical compatibility between the process fluid and the available pump housing materials. Generally, the goal is to select the most cost-effective option that is fully chemically compatible and meets all other application requirements, such as UV resistance for outdoor use or conductivity for explosive environments.

  • Selecting Diaphragm and Elastomeric Materials: Begin by reviewing the chemical compatibility of the various diaphragm and elastomeric options. Each material type and design offers distinct advantages and disadvantages. For instance, while PTFE offers excellent chemical resistance, it may have poor abrasion resistance. After identifying all chemically compatible options, evaluate the specific benefits of each material to determine the best choice for the application.

  
  

• Is PTFE the best diaphragm material for acids and chemical solvents?

  PTFE is often used in chemical diaphragm pumps for aggressive fluid compatibility. However, PTFE diaphragms are typically a higher-cost option. Wil-Flex® is another excellent diaphragm option, offering similar chemical compatibility for acids and solvents as PTFE but at a lower cost.

• What are the risks of using diaphragm pumps to transfer hazardous chemicals?

  When using AODD pumps for hazardous materials, always ensure exhaust systems and proper PPE are used. If a diaphragm ruptures, the exhaust should always be piped to a control area – either a safe handling area or back to the tank – since fluid can enter the air system if the diaphragm is breached. Always wear appropriate protection for eyes, lungs and skin when near hazardous fluids.

• What does the degree symbol mean when describing acid strength in chemical pumping?

  The degree symbol (°) refers to degrees Baume. In this case, 66° corresponds to 98% strength. You will often see this symbol used when describing sulfuric acid.