State of Technology Report for Force Main Rehabilitation, Final ...
State of Technology Report for Force Main Rehabilitation, Final ...
State of Technology Report for Force Main Rehabilitation, Final ...
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pipe’s design life. Once again, it would be reasonable to expect that any renewal liner using PVC<br />
material would be affected similarly by cyclic loading and should be designed accordingly.<br />
5.2.4 Other Considerations. <strong>Force</strong> mains do not have frequent service connections as in a water<br />
main, but nonetheless there are usually pressurized connections to other incoming or outgoing mains, air<br />
release valves at high points, and other inline fittings (valves, elbows, etc.). The protocol with practically<br />
all <strong>for</strong>ce main rehabilitation systems, except independent slipliners, is to terminate the liner with a special<br />
mechanical fitting that seals the end <strong>of</strong> the liner with the existing host pipe, and then incorporate a ductile<br />
or CI fitting <strong>for</strong> the connection to the fitting or valve. Slipliners, such as full thickness PE and PVC pipes,<br />
can be re-connected in the same manner as ordinary pipe made <strong>of</strong> these same materials. Electr<strong>of</strong>used<br />
fittings <strong>for</strong> PE and DI fittings <strong>for</strong> PVC are common.<br />
Another important design consideration in a renewal project is the intended design life <strong>of</strong> the rehabilitated<br />
system. The renewal can be a fully structural replacement <strong>for</strong> the existing pipe, in which case a design<br />
life <strong>of</strong> 50 years is desired. Or, the renewal may only be a corrosion barrier (Class I) or a close-fit semistructural<br />
liner (Class II or III) with a design life dependent on the continued structural per<strong>for</strong>mance <strong>of</strong> the<br />
existing pipe. If the existing pipe is incapable <strong>of</strong> handling the internal pressure due to external corrosion,<br />
then the design life <strong>of</strong> the renewal liner is going to be limited to that <strong>of</strong> the existing pipe. As reported in a<br />
recent report (WERF, 2009), the majority <strong>of</strong> sewer <strong>for</strong>ce mains are under 25 years <strong>of</strong> age with few over<br />
50 years, which is quite different from the age distribution <strong>of</strong> the nation’s water distribution system.<br />
Consequently, it is reasonable to expect that any renewal liner should be able to extend the design life <strong>of</strong> a<br />
sewer <strong>for</strong>ce main <strong>for</strong> at least another 25 years.<br />
5.3 Product/Material Standards<br />
The two main national organizations within the US that undertake development <strong>of</strong> consensus standards<br />
covering materials, products, testing methods and installation methodologies are ASTM and the AWWA.<br />
These bodies provide a <strong>for</strong>um <strong>for</strong> producers, users, and those having a general interest (e.g., government,<br />
academia) to write standards that best meet their needs. Representatives from each interested field are<br />
involved in the standards process, but the producer community normally takes a leading role. AWWA<br />
standards are solely dedicated to the water industry. Some products or linings that are used in the water<br />
industry may also have a place on the wastewater side. Epoxy linings are a good example <strong>of</strong> dual<br />
potential use. The National Association <strong>of</strong> Sewer Service Companies (NASSCO) has also developed<br />
some excellent guideline specifications and manuals <strong>of</strong> practice. Producer companies are solely involved<br />
in the NASSCO specifications so the user community’s interests may not be fully appreciated.<br />
The body <strong>of</strong> standards can be broken down into four areas – product/material standards, design standards,<br />
and installation standards, and manual <strong>of</strong> practices. Some <strong>of</strong> the standards serve more than one purpose.<br />
The purpose <strong>of</strong> this report is not to provide a detailed review <strong>of</strong> each pertinent standard, but rather to<br />
highlight some <strong>of</strong> the more important standards and especially those that are relatively new within the<br />
past 5 years and may have a use <strong>for</strong> sewer <strong>for</strong>ce main renewal.<br />
ASTM Product/Material Standards<br />
This section summarizes product/material standards by pipe type including those defined <strong>for</strong> PVC, PE,<br />
CIPP, and FRP/GRP materials.<br />
PVC Materials<br />
The following ASTM standards in Table 5-1 cover PVC materials used <strong>for</strong> renewal.<br />
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