Internal Corrosion Prevention

Pacific States Cast Iron Pipe Company offers a variety of pipe linings capable of handling most water and waste water applications.

Drinking Water Transmission and Distribution

Due to the extremely aggressive waters distributed by some public water supplies, Pacific States has improved its Portland cement mortar linings to handle such water without difficulty. Not only are the highest quality water, sand, cement and seal coatings used, but each step of the lining process has been studied in detail and improved where possible. Certification of quality is required of all lining raw material suppliers, and leaching and seal coat bonding tests are completed routinely. Each step of the operation is inspected frequently: pipe interior preparation, mortar mixing, centrifugal distribution of mortar into pipe, lining smoothness, initial set, and seal coating. It is our intent that this lining exceed the requirements of ANSI/AWWA Standard C104/A21.4 and that it will serve its intended functions - prevention of tuberculation and red water and provision of smooth flow characteristics without difficulty even in the most severely aggressive soft waters.

Pipe Lining Production

Pacific States cement mortar lining system includes the following:

Photo 1. High quality sand and cement are stored in silos and moved pneumatically to the cement mortar mixing unit.

Photo 2. Sand, cement and prewarmed water are added to the mixer in carefully controlled ratios. Mixing time is closely controlled.

Photo 3. Completed mortar is distributed into rotating pipe through a lance. The pipe is prewarmed during cold weather.

Photo 4. The lined pipe is spun to provide sufficient centrifugal force to distribute and smooth the mortar. Vibrators applied to the pipe's exterior promote a compact and uniform mortar lining.

Photo 5. Bells are rinsed clean of any residual mortar and the lining is lightly flushed with warm water.

Photo 6. The lined pipe passes through an environmentally controlled chamber to enhance intial set and reduce moisture to the proper level for seal coating.

Photo 7. A seal coat is applied to the internal surface of the lining to aid hydration by holding moisture in the mortar.

Photo 8. Completed pipe is stored in temperature controlled bays. Seal coat bonding is checked after final cure.

Photo 9. Leaching tests are completed on water exposed to the lined pipe in accordance with ANSI/AWWA Standard C104/121.4. The exposed water also is subjected to flavor analysis.

Wastewater Piping

Pacific States also manufactures specific pipe for wastewater piping situations including gravity sewers, force mains and waste treatment plant piping. Detailed specifications for epoxy, Protecto 401 or aluminous cement lined pipe are available upon request.

Pacific States Protecto 401

Pacific States' primary wastewater lining material is the Protecto 401 ceramic epoxy lining. This novolac epoxy/ceramic quartz pigment lining is ideal for a variety of sewer and industrial waste applications. It has exhibited superior mechanical bonding strength and abrasion resistance while protecting ductile iron pipe and fittings against interior corrosion.

Application of the lining occurs in a low temperature controlled environment ensuring that the 40-mil lining will not develop any residual stresses. Adherence to strict specifications from surface preparation to inspection are observed. Upon completion of the lining process each pipe must pass a 2500 volt holiday detection test.

Unlike most other ductile iron pipe foundries, Pacific States applies the Protecto 401 where the pipe itself is produced. This gives Pacific States control of the quality of the workmanship and the production/delivery schedule.

Pacific States Coal Tar Epoxy

Ductile iron pipe lined with catalyzed coal-tar epoxy is proven by field experience to be especially suited to severe waste water service. The application of this epoxy lining to Pacific States pipe is quality controlled to exacting standards. The interior surface of the pipe wall is sand blasted smooth to assure uniform lining thickness. The lining is applied in 10 to 12 mil (dry film thickness) layers until the specified lining thickness is reached, usually 20 to 24 mils. The lining at 24 mils thickness must have a permeability rating of .13 perms, a direct impact resistance of 100 in-lb., an abrasion resistance of 20 liters of sand per mil, an elongation of 5% and dielectric strength of 250 volts per mil when fully cured. In addition, the lining material is subjected to immersion tests in corrosive media, including 25% sodium hydroxide at 140° F and 3% sulfuric acid at 125° F along with other corrosive compounds. No failure is permitted. The result is a tough, smooth, tightly bonded, holiday-free (passes 67 volt wet sponge detection test) lining in ductile iron pipe.

High Pressure Applications

iron pipe has been serving Manti, Utah at an internal pressure of 1,100 psi without a single failure. This is more than three times the rated working pressure of 350 psi stated in ANSI/AWWA Standard C151/A21.51. For high pressure applications please consult your Pacific States representative for information on maximum allowable pressure. In most cases, pressure capacity will greatly exceed pressure rating in the standard tables. Pressure ratings for ductile iron pipe are C151/A21.51 along with maximum depths of earth cover. With ductile iron, for example, a 12-inch Class 50 pipe with a nominal wall thickness of .31 inches can withstand internal pressures up to 1,610 psi (based on minimum yield strength with all minus tolerances removed from the thickness). This 12-inch pipe would not actually fail until the internal pressure exceeded 2,300 psi (based on minimum ultimate strength of 60,000 psi).

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