Vented flow control device required? 1003.3.4.2 2009 IPC

[Darren Emery]

A newly adopted grease control ordinace is causing a number of grease interceptors to be installed locally. I'm running into all kinds of unique installations. The latest - a small (10gal) on floor interceptor has been installed without a vented flow control device. This seems to be a violation of the 2009 IPC.

However, the manufacturer's specs show a built in flow control device in the inlet tube, but it is not vented. Complicating further, the installation instructions show that this internal device should be removed if the interceptor is installed on the same floor as the fixtures being served.

What do you do when the manufacturer's specs directly contradict the plumbing code requirements?

If interested, the installation details can be viewed HERE.

 

[Gregg Harris]

The last sentence of 1003.3.4.2 would eliminate any contradiction, would it not ?

 

[Darren Emery]

Well - that's kinda what I thought - untill I read the commentary. Air entrainment is a key function of the flow control device. No air entrainment on this system. And - no flow control if installed per specs.

Thus the contradiction. Code says flow control device shall be installed per man. specs. Man. specs say don't install flow control device.

 

[Gregg Harris]

The flow control is the inlet assembly, the metering orifice is what is being removed if installed at same level and left in to compensate for head pressure if installed bellow is the way I read it.

What commentary are you referring to?

 

[Darren Emery]

2009 IPC commentary

 

[Gregg Harris]

that is what I thought you where refereeing to, the grease trap is still vented and the air entrainment helps to aid in the separation of the grease but IMHO I do not believe it effects the separation as implied in the commentary. Distance and temperature are the critical elements to the installation.

 

[gbhammer]

Well - that's kinda what I thought - untill I read the commentary. Air entrainment is a key function of the flow control device. No air entrainment on this system. And - no flow control if installed per specs. Thus the contradiction. Code says flow control device shall be installed per man. specs. Man. specs say don't install flow control device.

The commentary is not code and is only there to show the intent behind the code. In this case they show the intent behind the flow control device requirement, and failed to discuss the manufacture specs because they most likely believed that following the spec was self explanatory. There is no discrepancy, if the spec says no vent then no vent (the device is most likely designed to accommodate air entrainment and self siphonage).