I.P.S. Pressure/Irrigation (P.I.P) Installation Guide - JM Eagle

5.1.1 Deflection Testing
It is the position of JM Eagle that deflection testing of PVC pipe is unnecessary
when pipe is installed in accordance with the acceptable practices
stated in this guide. Most towns and municipalities limit initial deflection to 5
percent, when in actuality ASTM D3034 recommends PVC pipe deflection
7.5 percent of base inside diameter. Thus, exceeding these limits does not
necessarily indicate any structural damage, failure or reduction in life and
only add to the cost of the project. Proof of this position is that more than
750 million feet of PVC sewer pipe are performing satisfactorily in the field
today. On the other hand, where improper installation practices are known or
suspected, questionable bedding materials are employed, and/or installation
conditions are severe, deflection testing of these sections of the installation
should be considered advisable by the engineer. In the event that deflection
measurement is a requirement, please consult JM Eagle Publication JME-
05B, “Gravity Sewer Installation Guide.”
5.2 Testing Water Pipe
It is good practice to pressure test portions of a line as it is installed—before
the entire line is completed. Before testing, all parts of the line should be
backfilled and braced sufficiently to prevent movement under pressure. (See
Figure 19.)
In setting up a section of line for test, a provision for air relief valves should
be made.
There are three parts of the line to consider when testing:
1. The run of pipe, which must be backfilled sufficiently to prevent movement
under test pressure.
2. Thrust blocks at fittings, which should be permanent and constructed
to withstand test pressure. If concrete thrust blocks are used, enough
time to permit the cement to set must elapse before testing.
3. Test ends, which should be capped and braced to withstand the appreciable
thrusts that are developed under test pressure. Refer to
Section 3.9 on “Thrust Blocking and Anchorage at Fittings.”
IRRIGATION & I.P.S. PRESSURE INSTALLATION GUIDE
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