11-08 Cast iron force main

Question: 11-08Code Section: 7Date: 15 April 2011OBC 2006 Reference: 7.2.1.5., 7.3.2.6.(1), 7.3.4.1.(1),
7.3.4.5.(1), 7.3.4.5.(2)(c).

Question Submitted: Can the pump discharge from a sump pit or sewage ejector (force main) be cast iron “MJ” or
does it have to be of a more rigid joint such as grooved, threaded or soldered.


Interpretation: If the piping and fittings will be capable of withstanding one and one-half the maximum
pressure that will be created within the force main and the materials are approved for use on a
drainage system then a contractor could have a choice of various piping systems of materials.

Each scenario would be different based on site conditions and the pumps that are selected.

Pump specifications and flow charts would have to be submitted along with the details of pipe
run including length and difference in elevations in-order to verify that the proposed piping and
fittings will meet the code requirements.

See Code Requirement

7.2.1.5. Withstanding Pressure

(1) Piping, fittings and joints used in pressure sewer, forcemain or sump pump discharge
applications shall be capable of withstanding at least one and one-half times the maximum
potential pressure.

The piping and installation must also comply with all Code requirements, such as Sentences
7.3.2.6.(1), 7.3.4.1.(1), 7.3.4.5.(1), 7.3.4.5.(2)(c).