Installing new water softener, drain question

[freey29]

Purchased the Fleck 5600 after some research, installing Saturday. Cutting into the main drain, will this diagram be sufficient for drainage? I was thinking of putting a 2" backflow, but is it necessary?


http://imgur.com/a/436y2

 

[Treeman]

Hello freey29,

I apologize that I cannot give you any advice. I will be watching in order to learn.

You will need an air gap device where the softener line enters your new stand pipe.

I am curious about:
- will the pros recommend using a sanitary T instead of a wye to enter drain pipe?
-does the new stand pipe opening need to be above the horizonal drain line?
- you need to avoid an "S" trap situation
-how will the pros address the vent situation, if any?

Eager to hear what they say!

 

[Sponsor]

 

[Cacher_Chick]

Every trap requires a vent to prevent it from being siphoned. When the trap has been siphoned, the sewer gas comes into the house.

 

[Bannerman]

It is my understanding of US plumbing code, if the branch horizontal run to drain one appliance connection is less than 6', then a dedicated vent is not required although there would be no harm if one was installed. I further understand the upper vent stack connection would need to be a specific minimum distance above the highest drain connection and so the upper vent connection to the stack would likely be located within the attic.

Since the existing main stack can provide venting (wet vent) when the horizontal branch run is less than 6', then a 'Y' cannot be used so a sanitary 'T' is the appropriate vertical stack connection.

The link below includes a description and 2 diagrams of when a 'Y' maybe used.

I further understand there is a minimum standpipe length requirement above the 'P' trap and an air gap is to be installed at the top of the standpipe.

 

[freey29]

So should I be using a T instead of a Y? I see the diagram, but this would not be continuous water flow that restricts airflow. It will be a small amount of drain water from the softener

 

[Bannerman]

True. While I understand your reasoning for wanting to use a 'Y' as there would be less potential for sewage flowing from above to enter the branch, the code does not distinguish based upon the type of appliance or the expected water flow quantity or frequency.

You first mentioned a back-flow device but that too would likely restrict airflow, thereby increasing the potential for water to be siphoned from the softener's 'P' trap. Since the flow gpm is low, the horizontal section of drain pipe after the trap would probably never be filled and therefore not create a siphon event, but if you intend to comply with code requirements ...

 

[Bannerman]

Further to this, while there are conflicting opinions stated, see posts #12, # 15 & #29 in the link below, as written by a plumbing contractor in 2011.

https://www.ridgidforum.com/forum/m...ng-experts/40382-when-to-use-san-t-or-tee-wye

 

[Cacher_Chick]

Bannerman, the U.S. codes are have differences than that of Canada. In the U.S., it is not permitted to wet vent between floors, period. The only code-legal method to install a standpipe for such a purpose requires a seperate vent.

As you eluded to, fixture vents may be tied together, but not lower that 42" above the floor of the highest fixture served by the vent.

 

[Bannerman]

It is my understanding of US plumbing code,

As stated.

I now realize US codes are not always consistent between states and may even differ on a more local basis such as county to county. Perhaps the code requirements you specify, pertain to Land of Cheese.

Have you read through the links provided, in particular the posts specified, written by a plumbing contractor located in Pennsylvania, the same state as freey29?

 

[Cacher_Chick]

As stated.

I now realize US codes are not always consistent between states and may even differ on a more local basis such as county to county. Perhaps the code requirements you specify, pertain to Land of Cheese.

Have you read through the links provided, in particular the posts specified, written by a plumbing contractor located in Pennsylvania, the same state as freey29?

No, in truth, I don't look at other DIY websites. The plumbing codes that apply to most individual states are available online, and linked to right here in these forums. Local codes can offer variances, but those are normally more strict than the applicable state code. I have been around long enough to know that there is no wet venting between floors anywhere in the USA under modern plumbing codes. Though I make mistakes sometimes, I would rather see people read their own plumbing code and then ask questions about the parts which they might not understand.