Alfa Laval Unique PMO Plus® Mixproof Valve

The Pasteurized Milk Ordinance (PMO)

Paragraph 15p(B) of the Pasteurized Milk Ordinance (PMO) outlines the requirements for the use of mixproof valves in applications involving milk products and cleaning solutions to ensure the hygienic and safe separation of dairy products flowing concurrently through the same valve.

The PMO requires that:

• Both valve seats must be position detectable
• The leakage chamber, found in all mixproof valves, must have the same cross-sectional area as the valve body port connections
• The actuator must be fail-safe by spring-to-close

In 2007, the Food and Drug Administration (FDA) changed the PMO to allow clean-in-place (CIP) solution to clean one valve seat while product is flowing in the opposite housing. This change virtually eliminates CIP downtime, so processors can run continuous dairy operations and increase production.

In 2008 the FDA issued memorandum M-b-356, confirming that Alfa Laval’s Unique PMO Plus mixproof valve is Pasteurized Milk Ordinance paragraph 15p(B) compliant.

The following benefits make the Unique PMO Plus stand out from the competition:

• Proven design: Same fundamental technology used in the industry for more than a decade
• Retrofittable: Replacement of a few components enables conversion of installed Unique PMO valves to Unique PMO Plus
• Only three elastomers in the isolation chamber: Minimizes risk of product contamination
• Tested and FDA compliant to 145 psi: The highest operating pressure available for the widest range of process applications
• Designed with a mix of radial and axial seals: A proven, leading design to protect product
• Standard, single unit actuator: Simple operation with fewer moving parts
• Same wetted and actuator service kits as the unique PMO valve: No need to learn or stock new parts
• Maintenance friendly: No adjustments are required when reassembling the valve after service

Concept

This Unique PMO Plus Mixproof valve is based on the well proven and exceptionally flexible design of the Unique PMO Mixproof valves from Alfa Laval. It meets the demands from the 3-A/PMO (Pasteurized Milk Ordinance paragraph 15p(B)) standards saying that all movements have to be detectable, as well as the vent tube has to have the same or greater area than the connection pipe. Furthermore, the Unique PMO Plus meets the FDA demands for seat lift compliance M-b 356. This allows CIP flow to clean one chamber while product is running in the other chamber, thus eliminating CIP downtime. Finally, the actuator is fail-safe by spring-to-close.

Dimensional Data

Note: For the diagrams the following applies: Medium: Water (68°F). Measurement: In accordance with VDI 2173.