Section 327IAC3-6-13. Force main requirements

   In addition to the force main requirements specified throughout this rule, the following apply:

(1) Force mains shall be sized to provide a cleansing velocity of at least two (2) feet per second throughout the length of the sewer at the design pumping rate.

(2) Force main pipe and joint materials shall be equivalent to water main strength at design conditions.

(3) Air relief valves or other air relief devices shall be installed at every intermediate apex point where air may accumulate in the force main.

(4) Each air relief valve that exhausts above ground must be equipped with an exhaust pipe extending to a downward facing elbow covered with a corrosion-resistant, twenty-four (24) mesh screened opening at an elevation of eighteen (18) inches above ground level.

(5) Air relief valves shall be selected in accordance with the following:

(A) Automatic air relief valves shall not be used in areas:

(i) within the one hundred (100) year flood plain; or

(ii) where flooding may occur, such as in:

(AA) a pit;

(BB) a chamber; or

(CC) a manhole;

unless the automatic air relief valve is equipped with a downward facing exhaust pipe covered with a corrosion-resistant, twenty-four (24) mesh screened opening at an elevation of eighteen (18) inches above the ground surface and above the one hundred (100) year flood elevation.

(B) Manually operated air relief valves shall be used in areas:

(i) within the one hundred (100) year flood plain; and

(ii) where flooding may occur, such as in:

(AA) a pit;

(BB) a chamber; or

(CC) a manhole.

(6) The following reaction devices installed to prevent movement in pipes and fittings, of any material type, shall be designed in conformance with Section 3.8 of AWWA Standard C600-93, AWWA Standard for Installation of Ductile-Iron Water Mains and Their Appurtenances:

(A) Blocking.

(B) Tie rods.

(C) Joints.

(Water Pollution Control Division; 327 IAC 3-6-13; filed May 17, 1999, 12:11 p.m.: 22 IR 3093; readopted filed Apr 11, 2005, 2:45 p.m.: 28 IR 2470; readopted filed Jun 15, 2011, 11:15 a.m.: 20110713-IR-327110193BFA)