Bean animal overflow

[NathanH]

Why do some bean animal overflow diagrams show the main drain pipe as a straight pipe with strainer and some show it with the inverted U bend? All diagrams I see show the secondary with the durso style but wondering what the pros and cons are to plumbing the main drain that way.

 

[blaxsun]

I think your main is always typically the one with the strainer on it.

 

[RocketEngineer]

With the u-bend at the top of the siphon, it is less likely to pull in air as the water level in the box fluctuates. However, the con is on startup it takes some time to flush the air out of the top of the bend.

Technically, the secondary doesn’t need the Durso. A lot of systems use it to keep the trickle noise down.

 

[KStatefan]

All of these are based off the orginal BeanAnimal which used a coast to coast overflow and had a few different design requirements.

With the deeper boxes used in the external the 90 bend is not required to keep a vertex from pulling air in.

 

[Bluedore]

Agree with the above replies, the u-bend on the main is mainly to reduce the noise level.

 

[fishface NJ]

I have a bean animal. I would never use a strainer. It will clog over time