Thread: tube plumbed into kitchen sink drain

I have a photo, and I'll go get it if I have to, but I'm too lazy right now.

There is a small black plastic tube, about 1/4" O.D., directly connected to the kitchen sink drain, after the trap, with a saddle type fitting. The tube and the fitting are relatively new looking, in a 30 year old house. The tube goes through the floor into the basement, where it is hanging, not connected to anything. I have no idea what this used to be for.

The house is heated with a heat pump. This is not the AC condensate line and it's smaller than any condensate drain line I've ever seen. There is water softening equipment, but it has a typical drain tube (improperly) connected to the soil pipe.

Any clues, ideas, theories?

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John,

Most of those I see were connected as you say to water softening equipment. Maybe they just moved it to another location?

rick

left over from a reverse osmosis system? A quick guess.

Originally Posted by Jim Robinson

left over from a reverse osmosis system? A quick guess.

I second Jim's guess.

Originally Posted by John Arnold

directly connected to the kitchen sink drain, after the trap,

There is water softening equipment, but it has a typical drain tube (improperly) connected to the soil pipe.

Originally Posted by Jim Robinson

left over from a reverse osmosis system? A quick guess.

Left over from an improperly connected reverse osmosis system possibly.

They didn't connect it properly the first time, so why connect the new one properly?

IF THE SINK BACKS UP IT WILL LEAK TO BASEMENT. OLD REVERSE OSMOSIS TUBE.

The house probably had a reverse osmosis or similar system mounted in the basement at one time and thats where they ran the drain. The plumbing code here in Ohio states that there can be no drilling or tapping of any pipes and also prohibits the use of these saddle type valves also.

Here's the pic

Yep that is what a lot of the reverse osmosis installers do. It does not meet the plumbing code here in Illinois. They do make an air gap fitting that can be installed for the system. But since there is not system that is just an open pipe that can be venting sewer gasses into the home.

Originally Posted by Ron Hasil

I second Jim's guess.

I second guess Jim too.

Wait, I mean...

I agree Reverse O tube.

Ron, a lot of the RO systems have the air gap built in up at the underside of the dispenser. That way they can drop down with the saddle T into the drain line. However, if the line went into the basement, that would pretty much negate that air gap.

Originally Posted by Jim Robinson

Ron, a lot of the RO systems have the air gap built in up at the underside of the dispenser. That way they can drop down with the saddle T into the drain line. However, if the line went into the basement, that would pretty much negate that air gap.

Well here is one part of the code that deals with any type of water treatment units. And another part that forbids the use of saddle fittings. Plus the fact they installed it after the trap. If there is an air gap, you still would get sewer odors. Also with out the air gap it would be considered a cross connection of potable water and sanitary.

Section 890.760 Pressure Type Water Treatment Units

Wash water and rinse water drain lines from water softeners and other types of water treatment units shall discharge through a vertical air gap at least twice the diameter of the pipe, but not less than two (2) inches. Any water softening unit which depends on a venturi created by the flow of water from the water supply line to the softener, for the purpose of siphoning brine solution for regeneration, shall not be required to have a backflow preventer on the water supply line. All other types (those that depend on internal check valves to prevent backflow and/or have the inlet supply of water stopped during regeneration) shall have a double check valve backflow preventer assembly installed on the inlet water supply line.

Section 890.1320 Drainage System Installation
5) No pipe or fitting of drainage system shall be drilled or tapped nor shall any band or saddle be used.

This is an example of why the installation instructions rule ... as long as they are *more restrictive than the code*.

The codes say that the installation much be installed in accordance with the manufacturer's installation instruction *and* the code, and, typically, the code being general in nature is less restrictive, leaving the manufacturer's installation instructions *typically* as being more restrictive ... *typically* ... and this is a good example of that being atypical.

Originally Posted by Jim Robinson

Ron, a lot of the RO systems have the air gap built in up at the underside of the dispenser. That way they can drop down with the saddle T into the drain line.

Originally Posted by Ron Hasil

Well here is one part of the code that deals with any type of water treatment units. And another part that forbids the use of saddle fittings.

Section 890.1320 Drainage System Installation
5) No pipe or fitting of drainage system shall be drilled or tapped nor shall any band or saddle be used.

Thus, in this case, the code is the most restrictive. Installing it in accordance with the code does not "violate" the installation instructions, it simply "exceeds" the installation instructions.

Very good probability that is a drain line for a reverse osmosis water filtering system. If the faucet for the system was mounted at the sink rim, and had an integral air gap for the drain, then it would be fine. In its current condition, there is an open waste line allowing waste system gases into the residence. It should have been capped off when the RO system was removed. I would write it up. It needs to be dealt with, one way or another. It can't be left the way it is. I isn't safe.

Originally Posted by Randy Aldering

If the faucet for the system was mounted at the sink rim, and had an integral air gap for the drain, then it would be fine.

Still not allowed to drill and tap and saddle tee that fitting into the drain line, air gap or no air gap, manufacturer's instructions or no manufacturer's instructions, the code simply does not allow it.

To make a legal connection for a RO system it needs its own p-trap with a Air gap Adapter installed on it. Here is a sheet for one type. http://www.gamurdock.com/gam/images/.../zoom/air2.jpg

The second photo is a different type of adapter and shows the allowed places to install it. Notice it is not after the P-trap. Here is the link for these type adapters. This is for the RO systems with an air gap. RO Drain Kits

I'm wondering if there is a need for a "back wash" valve on this drain serving the water softener discharge tube in a crawl space.
Can't find the code on this.

Originally Posted by Tom Edwards

I'm wondering if there is a need for a "back wash" valve on this drain serving the water softener discharge tube in a crawl space.
Can't find the code on this.

Don't know the code rule, but I know that thing will leak sewage!
Just picture the 4" pipe in the background full of crappy water.