Update 7/13/21: I took some additional pictures of the plug, as well as the pipes the plug is used on, and added a description.

I recently turned on my irrigation system after it having been winterized last year. I did this via a blue-handled valve located outside in an access box sunken into the ground with a large, green pop-off cover.

Much to my surprise, when I opened the valve, I was shot in the chest with a jet of water. After shutting the valve back off, I saw that there was an open pipe through which the water had shot. It had a threaded end and attached to it was this black rubber thing.

Plug folded over as it was when in use Bottom-up view of plug Side view of plug Plug screw detail Valve assembly in access box Detail of valve assembly Open pipe where plug should go Closed pipes sealed with similar plug

The plug itself is made of two parts. The first part is made of a soft, pliable rubber with a loop at each end. The larger loop is designed to stretch around a pipe and keep the whole thing from dropping to the ground when it's unscrewed. The smaller loop effectively functions like an o-ring. The second part is a hard plastic thumb screw. This screws into a pipe in order to press the o-ring flush with the opening. The top side is chewed up from when I tried to tighten it using a pair of pliers.

I tried to screw it back on, but when I opened the valve again, it must not have been making a good seal with the pipe because small jets of pressurized water were shooting out from under it. I spent a while mucking around with it, tightening it to varying degrees, but it always leaks.

What is this thing called? I've had no luck googling for variations of "seal", "cap", "bleed screw", etc...

  • Is it rubber or plastic? Does the top part look like it has had tools on it? What do the other parts look like? It's hard to answer without some context.
    – isherwood
    Jul 13, 2021 at 13:26
  • What manufacturer produced your irrigation system? These quick connects/plugs come in all flavors - Looks like one I found that Orbit made but I wanna make sure.
    – Aww_Geez
    Jul 13, 2021 at 15:22
  • Probably a type of pipe plug. It might have just loosen over time or the system was not winterized as well as you thought.
    – crip659
    Jul 13, 2021 at 15:55
  • It looks like you might have lost the original account. You should request an account merge
    – Machavity
    Jul 14, 2021 at 12:34

2 Answers 2


Try searching the following:

  • PVC sprinkler cap
  • MPT barb adapter
  • Irrigation system fittings

Or take it to your local hardware store or garden center.

It's hard to tell what that chewed up part once was, but the above should be a good start for your search. Good luck!


Try searching "drain plug for pump". a number of them show up but the details are lacking. If there's a pool supply store around you, try going there. If not, you might be able to configure something at your home store.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.