By Rick Andrew

Post-mix beverage applications present an interesting and special situation in the world of water treatment. Post-mix treatment involves water that is blended with carbon dioxide (CO2) and concentrated beverage syrup to produce soft drinks at the point of use. This locally available water may have character­istics that could negatively impact the color, clarity, odor, and taste of the soft drink, which then becomes a problem for consumers, restaurants, and soft drink companies. Recognizing and responding to this market need, water-treatment system manufacturers have developed specialized product lines focused on the treatment of water used in post-mix beverage applications.

Water Treatment for Post-Mix Applications
Technologies used in water treatment for post-mix applications include sediment filters, carbon filters (including carbon blocks and granular activated carbon), scale control cartridges, reverse osmosis, and hollow fiber membranes. Other technologies may include softening, ultraviolet systems, and ion exchange.

Water-treatment professionals are key to optimizing application of these technologies based on source water characteristics and the desired characteristics of the water to be used in the post-mix beverage dispensing application.

FIG 1. Definition of Commercial Modular System Commercial modular system:
A system consisting of multiple components attached to a manifold, produced specifically for food service applications, installed by an authorized plumber or authorized agent of the manufacturer, and not intended for use in residential applications.
Source: NSF/ANSI 330 Section 3.35.

Soft drink companies have decades of experience in the field, understanding well the implications of various water sources and levels of water quality on their beverages. They have also performed research into the optimal water chemistry for their products. Soft drink producers also know how water chemistry influences the taste of their beverages, both positively and negatively. Residual chlorine or chloramines are typically an area of focus.

Because of this specialized knowledge, highly engineered products for water treatment in post-mix fountain beverage applications have been developed. Along with product devel­opment, there has been significant learning among water-treatment professionals in applying these technologies to achieve desired treated water quality.

NSF/ANSI 42 and 53 and Post-Mix Beverage Dispensing Systems
Based on the needs of the water-treatment equipment market for post-mix beverage dispensing systems, the first requirements for commercial modular systems were introduced into NSF/ANSI 42 and 53 in 2005. The definition of these systems (Fig 1) clarifies that commercial modular system requirements were developed specifically for post-mix beverage dispensing applications.

These standard requirements are not intended to cover products used in consumer installations. Such systems are configurable in the field by qualified water-treatment professionals depending on local water conditions and could be unintentionally misused by nonprofessional consumers. Commercial modular systems typically include an array of possible treatment elements that can fit into specially designed manifolds. These configurations provide flexible treatment-system options appropriate to specific water quality situations. Such open-ended configuration could be confusing to consumers and result in inappropriate and ineffective installations. One example of an inappropriate installation would be including two dissimilar modular elements in a parallel flow con­figuration, thus leading to uneven flow and incomplete treatment.

Proper application of commercial modular systems is critical to their effectiveness, which is emphasized by the standard require­ment that they be installed by an authorized plumber or authorized agent of the manufacturer. The standard requires that this provision be explicitly stated on the modular elements themselves (Fig 2).

NSF/ANSI 42 and 53 are structured this way to allow for appropriate requirements and evaluation for these systems, which can have so many configurations in the field. This structure facilitates the manufacturer’s ability to provide claims and capacity information specific to a modular element on the element itself, as opposed to identifying, naming, and labeling each possible system permu­tation associated with a given manifold system.

FIG 2. Application Statements for Commercial Modular Systems
8.2.2 Commercial modular manifolds shall have a permanent plate or label affixed in a readily accessible location on the system that shall contain, at a minimum, the following information:
• general system name;
• the statement:
“Not for residential use. Food service applications only. To be installed by an authorized plumber or an authorized representative of the manufacturer only.”
• statement that this modular element is NOT for use in residential applications;
• name and address of manufacturer;
• maximum working pressure in kPa (psig);
• maximum operating temperature in °C (°F);
• statement for systems claiming VOC reduction:
“Conforms to NSF/ANSI 53 for VOC reduction. See performance data sheet for individual contaminants and reduction performance.”
• manufacturers may reference individual chemicals from Table 8.1 on labels, manuals, or promotional materials if such information conforms to the following:
• percent reductions, if specified, are either less than or equal to those specified in Table 7.4, or additional testing is completed to justify the claim for a higher percent reduction.
• reference to individual chemicals from Table 8.1 shall not imply that specific testing for the chemical was conducted if only the surrogate test was completed.
• statement for systems claiming perchlorate reduction on waters containing nitrate:
“Do not use this system on water containing greater than 10 mg/L nitrate nitrogen without pretreatment to remove the nitrate. The water supply must be analyzed for nitrate nitrogen and nitrite nitrogen before the installation of the system.”
• failure to observe these instructions could produce water that exceeds drinking water standard for nitrate.
• statement for systems claiming perchlorate reduction that were tested with minimal hardness in the test water:
“Do not use this system on water containing hardness greater than 50 mg/L (3 grains per gallon) without pretreatment to remove hardness.”
• statement that spent adsorption media will not be regenerated and used.
Source: NSF/ANSI 53 Section 8.2.2.

8.2.4 Modular elements shall have a permanent plate or label affixed in a readily accessible location on the modular element that shall contain, at a minimum, the following information:
• modular element model number;
• functional description of modular element (e.g., chemical reduction or mechanical reduction, or both);
• statement that the modular element conforms to NSF/ANSI 42 or 53 for the specific performance claims verified and substantiated by test data;
• statement that this modular element is NOT for use in residential applications; and
• the manufacturer-specific standard head or manifold to which the element can be inserted.
Source: NSF/ANSI 53 Section 8.2.4.

The manufacturer also has the option to provide a performance data sheet for each modular element rather than for each possible system permutation. Information specific to the modular elements or systems must be included in the performance data sheet (Fig 3).

FIG 3. Additional Performance Data Sheet Requirements for Commercial Modular Systems
8.4.2 For commercial systems, in addition to the requirements set forth in Section 8.4.1, additional considerations are as follows:
• a performance data sheet may be developed for each modular element of the system, and/or for a group of modular elements; and
• the performance data sheet shall include all of the configurations, providing the following information for each:
• tested performance claims;
• rated service flow in LPM or LPD (GPM or GPD);
• rated capacity / rated service life in L (gal) (if applicable);
• maximum working pressure in kPa (psig); and
• maximum operating temperature in °C (°F).
Source: NSF/ANSI 53 Section 8.4.2.

Unique Situations Addressed by the Standards
Water-treatment manufacturers have developed sophisticated and specialized treatment technologies to fulfill the needs of post-mix beverage dispensing applications. These technologies allow qualified water-treatment professionals to configure systems that help assure consistent and pleasing taste for soft drinks and beverages dispensed from a post-mix system.

The combination of effective treatment technology and water-treatment expertise allows the desired outcome of consistent and pleasing taste. If one element is missing, the result may not be as positive.

Special provisions developed in NSF/ANSI 42 and 53 for commer­cial modular systems support this market reality. Commercial modular water filters that conform to the full requirements of the standards, including safety of materials in contact with water, structural integrity, contaminant-reduction performance, and clear labeling and presentation of product specifications and use instructions, provide an appropriate standard for rigorous evaluation that these filters are safe and effective.

About the author
Rick Andrew is NSF’s Director of Global Business Development–Water Systems. Previously, he served as General Manager of NSF’s Drinking Water Treatment Units (POU/POE), ERS (Protocols) and Biosafety Cabinetry Programs. Andrew has a Bachelor’s Degree in chemistry and an MBA from the University of Michigan. He can be reached at (800) NSF-MARK or email: [email protected]


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