HOBAS centrifugal cast fiberglass reinforced polymer mortar (CCFRPM) pipes now convey process wastewater flows at Anheuser Busch breweries in Houston and Columbus. The new buried pipes are part of an energy saving, environment friendly, anaerobic pre-treatment system known as the Bio Energy Recovery System (BERS). The treatment process itself uses less energy than many municipal units that perform the same function. Additionally, a methane gas by-product is recovered and is used as fuel for Anheuser Busch boilers, thus saving more energy and protecting the environment.

Varied Conditions

These two BERS projects utilize nearly 9000 feet of 18" and 20" diameter, HOBAS vinyl ester resin lined, pressure and gravity pipes and associated fittings including three dozen elbows, more than ten laterals, several flanges and a reducer. The pipes experience a variety of conditions. External loads include surface traffic, cover depths from 2 feet to 17 feet and, occasionally, water head to grade. The corrosive wastewater temperature is normally in the low 100 degrees F. with peaks possible to 160 degrees F. The pressure lines operate at about 30 psi with peaks expected to approximately 50 psi.

HOBAS Best Value

Several types of pipe used on past BERS projects were evaluated for these two systems. Judgment criteria included the above noted conditions, the capability to be leak-free, expected life and cost. Plastic lined metallic products easily met the operating conditions, but the life span of the internal linings has been unsatisfactory. 316 stainless steel, a favored material, is very expensive. HDPE pipes have excellent corrosion resistance and a competitive price, but require more care in underground installations. HOBAS pipes, although not the least expensive nor the highest performer in each category, were selected as the best value.

Successful Installation

Contractors, Birdwell Construction in Houston and the State Group in Columbus were first time HOBAS pipe installers, but both had lots of praise for the product when their jobs� were completed. They found assembly of the pipes and fittings using the gasket-sealed, push-together, HOBAS FWC couplings, fast, easy and sure. And because the FWC coupling seals at any location along the pipe barrel, field length adjustments were quick and simple. Burial proved very reliable using a dumped stone pipe zone surround. However, few jobs are without any problems and these two were no exception. In both cases, a couple of damaged pipes had to be replaced after burial. This was easily accomplished by removing the effected areas and tying-in new pipes using mechanical couplings.

Present & Future

The completed installations passed 50 psi (Houston) and 60 psi (Columbus) hydrotests without any leakage! Anheuser Busch engineers are pleased with the performance of their HOBAS CCFRPM pipes and are already considering them for additional systems. Finally, it may be coincidence or it may be fate, but each HOBAS pipe is dated during production, the same as the famous Anheuser Busch beers.