Commercial 3 compartment sink connected to 2" pvc pipe, this goes to an 1 1/2" P trap which goes back to a 2" line which enters a gas trap, which then goes into main line. All this is new install. I replaced old cast iron gas trap with new Wentworth grease trap. Instructions said to use included restrictor between sink and trap which i did. This restrictor had a 1" vent on it which instructions said to vent above sink water line which I did placing it up into splash guard on sink. Drains smelled terrible, so I removed restrictor and vent and placed the 1 1/2" P trap thinking it would eliminate smell; it is now worse than before. What's up?

I think the T vent should be reassembled as it can be adjusted and used as a flow control device as it is meant to be using the "restrictor". Slowing the flow of water down will make your interceptor work better as it catches more grease. I am more concerned about having a 2" line reducing down to 1 1/2" and them back to 2". You are going to have problems in the future. Here in the states most three compartment sinks are indirect waste dumping into a floor sink.

Hi Dqdave

Absolutely agree with Dcplumber on all counts. I also noticed that you did not mention a separate VENT (not the restrictor vent) for the grease trap. Here, the restrictor needs a vent AND the grease trap needs a vent installed downstream of the grease trap...betting that will help reduce the smell issue you are having...;)

Back to you...

Mark

Hi Dqdave

Absolutely agree with Dcplumber on all counts. I also noticed that you did not mention a separate VENT (not the restrictor vent) for the grease trap. Here, the restrictor needs a vent AND the grease trap needs a vent installed downstream of the grease trap...betting that will help reduce the smell issue you are having...;)

Back to you...

Mark
I placed the 1 1/2" P trap to reduce flow like the restrictor. I will redo the restrictor and vent but it smelled then also. After grease trap it is also 2" and connects into wall connection that is vented. The system never had a trap of any kind before. I am surprised the 1/1/2" trap didn't stop smell. Would it be wise to put a 2" trap then the restrictor and vent before entering the grease trap?

I think the T vent should be reassembled as it can be adjusted and used as a flow control device as it is meant to be using the "restrictor". Slowing the flow of water down will make your interceptor work better as it catches more grease. I am more concerned about having a 2" line reducing down to 1 1/2" and them back to 2". You are going to have problems in the future. Here in the states most three compartment sinks are indirect waste dumping into a floor sink.
This store was built in 1979. Today I would need a grease interceptor outside building in main line. I placed the 1/1/2" P trap to restrict flow. It smells more if and when I clean grease trap.