When there are multiple pumps and tanks arranged in a series in a food or pharmaceutical applications, it is recommended that mixed proofed valves are installed to prevent cross contamination between the dissimilar products or between product and washing detergent and sanitizing detergent.
Thankfully there are food grade mixed proofed valves available to ensure your products are protected from cross contamination. There are, in fact, a few different types available depending on your budgets.
Compare the two proofed valves below.
Double butterfly valves:
| Use | Cross contamination prevention |
| Reliability | Good |
| Maintenance skill level | Low |
| Valve actuation | Auto or manual |
| Capital cost | Low |
| Repair cost | Low |
| Leakage detection | Yes, leakage to atmosphere |
| Cleanability | Excellent and simple, CIP. |
Double seat valves:
The double seat valves are more complicated style of valves with extra functions such as seat cleaning and pressure balanced designs. However, these valves cost more than the double butterfly valves to purchase and to maintain. This type of valve, however, is excellent when used as valve, matrix. The valve matrix allows the operator to use their system in a very flexible way such as one tank to filler while the other tank to fill simultaneously.
| Use | Cross contamination prevention |
| Reliability | Good |
| Maintenance skill level | High, some design needs special tools |
| Valve actuation | Auto (typical) |
| Capital cost | High |
| Repair cost | High |
| Leakage detection | Yes, leakage to atmosphere |
| Cleanability | Excellent and require automation, CIP. |
Sepak Industries has both types of leakage proofed valves in their range, please contact sales@sepak.com.au or phone us +61 2 9618 1445 for more information or for installation at your factory.