I'm sure this is an odd question, but here it goes. One of my kids is currently obsessed with plumbing, and wants the sink to drain slowly.

Our drains, as for as I know, are pretty typical, and have white plastic p-traps.

Is there anything that I can buy and connect to the drain, either before or after the p-trap, to intentionally make the sink drain slowly? Even better if there's a way "turn it off" without taking the part back off.

I know there are shut off values, but those all seem to be for intakes, not for drains. And those, as I understand it, use different sized pipes, and you can't typically mix and match parts between them.

And of course, normally it's a really bad idea to "close" or partly close your drain, since that is past where the overflow connects. But I would rather have a safe and reversible way to "clog" the drain, rather than finding out later that the drain was intentionally clogged by my son with whatever was on hand at the time.

  • 3
    Something simple like small flat dish(cup holder/saucer) will stop/slow down draining. Can also be moved a bit to speed up/slow down draining. A glass type will let them see the water draining. Kid sounds like me, weird.
    – crip659
    Jan 17 at 19:50
  • 2
    Kid sounds like a kid - interested in the world around her.
    – FreeMan
    Jan 17 at 19:52
  • 2
    Partially closing the stopper that's typically installed on most drains seems like the easy and obvious choice, is that not an option? Jan 17 at 19:57
  • Come over to my house and pull the gunk out of the drain I have that's running slow. Win for both of us! Jan 17 at 20:19
  • 1
    @Tim That stopper need not be completely open or completely shut, you can pull the lift arm partway up to close the drain partway. Or, re-seat the pop-up arm lever where it attaches to the stopper so that the drain is partly closed when the pop-up is all the way down. I've definitely reinstalled the arm lever in the wrong hole before, which made it impossible to open the stopper all the way and caused slow draining. Jan 17 at 22:12

1 Answer 1


Is there anything that I can buy and connect to the drain, either before or after the p-trap, to intentionally make the sink drain slowly?

You can buy PVC ball valves in the same size as your sink drain. Just use the search term "pvc ball valve" in your favorite search engine. You will need to do some fitting research, and your local big box store may not carry a 1-1/4" or 1-1/2" PVC glue ball valve. You'll also most likely need to do a little bit of destructive plumbing, but the valve itself won't cause any damage long term to the drain, it'll just be... weird. It can always be removed later as well.

If you put it on the p-trap itself it will be easier to remove later, but where it is easiest to insert it will depend on what's below your sink and what options are available to you to buy.

PVC sizes are PVC sizes, no matter the pipe's purpose or thickness. The listed size is always the outside diameter of the pipe, and the internal diameter is determined by the wall thickness. There's no difference between supply and waste PVC in terms of compatibility other than that the box store is unlikely to carry parts for supplies as big as typical waste lines.

If you want to get really fancy, you could re-plumb the sink with glass piping, so that kiddo can see what's going on...

  • Do you mean something like this? homedepot.com/p/… How would you connect it though? If I compare that to a p-trap that looks like mine, let's say this one homedepot.com/p/… it looks like threads are different (inside vs outside), and it's made of polypropylene so I'm guessing the normal PVC solvent welding is out of the question. I get the impression that these are designed to make it really hard to accidentally mix and match them.
    – Tim
    Jan 17 at 22:08
  • To at least partly answer my question in my last comment, some googling suggests there's something that's called a "Marvel Adapter" that would work. I see some bundled with p-traps.
    – Tim
    Jan 17 at 22:25
  • you can use furnco connectors. just solvent in some male pieces to the 1.25 pvc ball valve and then furnco on both ends of the cut poly. to remove just use 1 furnco to reconnect Jan 17 at 22:29
  • Tubular products used for waste, such as tailpieces, tubular P-traps, and other slip-joint fittings are specifically different in the way they are sized compared to PVC piping. They are not compatible at all as it applies to glue connection. Tube is sized by actual O.D. (e.g. 1 1/2", 1 1/4") whereas pipe is sized by nominal I.D. The only thing that is the same between the two product types is the thread that is used. The statement that "PVC sizes are PVC sizes, no matter the pipe's purpose..." is incorrect; unfortunately it is not that simple. Jan 18 at 13:27

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