Texas City, Texas Product: Grand Prairie installs 10,000 feet of Hobas pipe
When Grand Prairie, TX, started work on recent sanitary sewer projects, it called on HOBAS Pipe of Houston, TX. The new pipeline, varying in size up to 110" in diameter, will allow the city to take an older 60" diameter line out of service. It will meet needs til 2020. The original West Fork Interceptor was put in service in the early 1960s and is one of the major interceptors that transports wastewater flows to the 162-mgd Central Regional Wastewater System (CRWS) Treatment Plant...
GRAND PRAIRIE, TX, June 6, 2006 -- When Grand Prairie, TX, started work on recent sanitary sewer projects, it called on HOBAS Pipe of Houston, Texas, to supply more than 10,000 linear feet of large diameter pipe. The new pipeline, which varies in size up to 110 inches in diameter, will ultimately allow the city to take an older 60-inch diameter line out of service.
The original West Fork Interceptor was constructed and placed in service in the early 1960s and is one of the major interceptors that transports wastewater flows to the 162 million-gallon-per-day Central Regional Wastewater System (CRWS) Treatment Plant. The new interceptor is expected to meet system requirements through the year 2020.
Exceeds Design Life
Trinity River Authority (TRA), which owns and operates the system, specified two options. The first was centrifugally cast fiberglass reinforced polymer mortar (CCFRPM) pipe, selected for its longevity. Here is an excerpt from Intra, the TRA newsletter: "Because of the corrosion resistant aspects of the centrifugally cast fiberglass pipe material, the pipe should be able to serve the region well beyond the minimum 50-year design life requirements of the Texas Commission on Environmental Quality."
The Intra article covered several other factors TRA considered when specifying a pipe material: "The West Fork (WF) Relief Interceptor will be located in unstable soil conditions in a relatively narrow space between existing pipelines and a levee that surrounds the CRWS plant. In addition the gravity-fed pipe must be placed at depths varying from 20 to 42 feet underground."
To safely handle the loading condition from the static soil column and the dynamic live loading, HOBAS provided a pipe with a minimum pipe stiffness of 46 psi. Pipe stiffness was increased to 72 psi in areas where soil conditions required cover depths greater than 20 feet. The other specified pipe material was a 360-degree PVC lined concrete pipe.
Archer Western Construction of Arlington, Texas, installed the first phase, WF-1, which includes 108-inch pipe. The second phase, WF-G-2 that is now in service, was installed by Oscar Renda Contracting (ORC) of Roanoke, Texas.
Contractors used several installation methods throughout the various phases of the project. Although the majority of the pipe has been installed by direct bury, CCFRPM pipes were also utilized inside a two-pass system and in above ground applications.
WF-G-2 is one of several projects ORC is installing using HOBAS pipe. ORC has been using HOBAS for many years due to the products advantages. "We love the product and the staff. The pipe provides tremendous advantages over concrete pipes due to the lighter weight and fewer joints. This allows us to increase our daily production. It is rare to see the installation rates with other materials that we have been able to achieve with HOBAS. We have seen installation rates of up to 800 feet per day with the 90-inch diameter and 600 feet a day with the 104-inch diameter. I can attribute this to the ease of installation," said Rudy V. Renda, regional manager, ORC.
Of course, there are reasons for the success of the installations in addition to the pipe. ORC, a family-run business, is continually striving to provide safer, higher quality techniques for installation. "We began with one machine over 30 years ago, and now we compete on some of the largest municipal projects in the nation. A driving force behind the company's growth is our team approach. All levels of the organization contribute ideas and influence our success," Renda said.
Superior Test Rates
Given the diameter of the installation, the length of the projects, and the installation rates, it was not uncommon to lay a week's worth of pipe before testing was accomplished. This could be performed with confidence due to the reliability of the joining system.
"It is very rare that we have complications during the testing phase. However, when we have had problems, they can be quickly and easily repaired without having to excavate the pipe," said Renda. "The fiberglass material is very reparable and HOBAS field service technicians are available to perform the work or train installation crews on site."
Continuing With HOBAS
The next Phase of WF will soon begin, HOBAS has again been chosen by the installation contractor, BRH Garver of Houston, Texas. The project includes over a mile of 90-inch diameter HOBAS pipe to be installed by direct bury.
HOBAS (www.hobaspipe.com) has been manufacturing pipes at the Houston, TX, location since 1987. Since then, over 3.5 million feet of pipe have been installed throughout the United States for applications including sanitary and storm sewers, potable water and industrial applications.
A HOBAS spokesperson said, "Use of CCFRPM has been rapidly growing as new customers learn of the superior performance and existing customers return to enjoy the cost saving benefits and consistent product quality."
HOBAS pipe is manufactured in sizes from 18 inches to 110 inches in pressure and non-pressure classes.