Polyphosphates
for scale and corrosion control

Tramfloc^® Potable Water Treatment Formulations are NSF standard 60 approved to
reduce and eliminate scale and corrosion for control in piping and fixtures.

Polyphosphates for scale and corrosion control are among the few recognized substances which can be safely added to potable water to produce a significant improvement in many water quality parameters. Over 200 phosphate-based products are now ANSI/NSF Standard 60 certified for use in potable water treatment. Many of these are virtually identical competitive offerings.

Success of a treatment program depends on choice of the most effective product and technology, and proper application (start up, feed rate, monitoring program). Remember....

(1) All phosphate technologies have a record of success in specific applications;
(2) Each phosphate technology also has a record of failure when inappropriately applied.

Treatment Objectives

The objectives of a chemical treatment program are defined by the problems that a system manager wishes to correct or avoid. Examples include:

• excessive lead and copper residuals at the tap
• red water complaints
• scale build-up in the distribution system
• excessive treatment costs
• THM formation, and
• excessive asbestos fiber counts

Identification of these treatment objectives for will largely eliminate inappropriate technologies and narrow the field of choices.

Water Characteristics

Water quality, defined by specific levels of contaminants measured in the water, will also eliminate many potential treatment technologies and influence any final treatment recommendation.

Zinc Orthophosphates                                            Aggressive Waters

Advantages:

• most comprehensive and effective corrosion control
• effective lead and copper control
• best galvanic corrosion inhibitor
• offer flexibility for system Management

Limitations:

• contribute to zinc load at wastewater treatment plant
• cannot be used above pH 8.1

Zinc Orthophosphates as a technology provide the most effective and comprehensive corrosion inhibition. Zinc orthophosphates have traditionally been used to stop colored water caused by bleeding tuberculation and have a long history of success. This technology is very effective in aggressive waters with no source iron and manganese to sequester and where calcium stabilization and scaling are not a concern. Zinc orthophosphates have demonstrated particular effectiveness in providing effective lead and copper protection. Zinc orthophosphates reduce asbestos fiber counts and protect cement pipe.

Orthophosphates                                                 Aggressive Waters

Used exclusively in aggressive waters, straight orthophosphates can be considered somewhat an extension of the zinc ortho's in that the blend ratio is so high that zinc has virtually been eliminated.

The benefits of orthophosphates are much more limited in comparison to the zinc orthophosphates. Orthophosphates have proven very useful in situations that require non-zinc lead protection without red water protection. In contrast to the di-polar functionality of the zinc orthophosphates, straight orthophosphates offer only anodic corrosion control. The entire focus is on controlling lead residuals.

Page 2: polyphosphates, more about them...