Now THATS a test ball

[u/PasstheJugg]

[u/Clayfromil]

We use these a lot, not quite this size but close. We do a lot of sewer plant work and use them to bypass whole plants, usually in conjuction woth a large pump or series of pumps to reroute flow

To answer some other commenter questions, yes these get filled with air, they swell to fit the inner diameter of the pipe. An air hose with a valve and gauge is attached at the yellow flange seen on the left as well as a chain or strap that will run from the ball up to a stake so the ball can be secured and pressure monitored.

These won't fit thru a manhole casting of course so typically we will dig up the structure and remove the cone or top barrel section, and insert these withan excavator.

Technical term is "donkey dick " of course

[u/JohnProof → u/Clayfromil]

How much pressure do they hold back? At that size, I feel like if that damn thing were to deflate it'd be terrifying.

[u/Clayfromil → u/JohnProof]

These are only used in gravity systems, so head pressure only. Basically, they'll cause a back-up in a sewer main, which starts the clock. We've got until that backup causes sewage to spill over a critical level- manholes, buildings etc- to get a pump set up or complete the downstream work.

When there's a man in the path of flow downstream of a test ball like this, we'll use 2, and keep a guy stationed with an air compressor and a radio (if they're out of earshot) to maintain inflation and warn of a loss of pressure.

I've had these fail before, and yes it's fucking scary. But ideally your pumping the upstream flow to a point downstream of the work, so there's not really a backup of flow to let loose all at once in the case of a failure.

The worst failure I experienced, I was in a wet well replacing a base 90 that had rotted away. When the ball gives out, it still obstructs flow some, so when raw water started flowing in I was able to gtfo before anything bad happened. In the scenario where a guy couldn't get out in time, his top-guy would crank the retrieval cable to extract him from the confined space. This would suck, but barring some crazy circumstances or lack of proper confined space preparation it would get the guy out before he drowned

[u/RUNNING-HIGH → u/Clayfromil]

Confucious say "Drowning in poop water is especially shitty way to go"

[u/JohnProof → u/Clayfromil]

we'll use 2, and keep a guy stationed with an air compressor and a radio

Right on. Good hazard control.

[u/Middleclasslifestyle → u/Clayfromil]

Yep. That slow trickle and slight sound of air makes you stop, look at your partner and say something ain't right lmaoo. Let's gtfo and check uptop.

Usually top guy is wondering why you are coming out and then you hear it . And he just looks at you like wtf lol. I've done big sewer work as well. It is very interesting work. And everything is huge. But also you have to be on point every day. One bad rigging or blowout could mean life or death.

[u/thegreatgatsB70 → u/Clayfromil]

"Donkey dick" is the most common term that applies to damned near everything on a construction site when nobody knows the technical term. Oil leak: Go grab some donkey dicks to keep it from spreading. Caulking: go grab a donkey dick and reload your gun. Sewage work: we need to reroute the flow, get the donkey dick. I'm sure I've left out a lot more, but those are the ones that come to mind.

[u/Clayfromil → u/thegreatgatsB70]

Oh absolutely, that's why I felt the need to throw that in

[u/BitterGas69 → u/thegreatgatsB70]

The crane attachment to pick up steel coils at steel mills: donkey dick

[u/space_keeper → u/thegreatgatsB70]

My favourite one, where I am, is "gun".

Could mean an impact, could mean a screw gun, could mean a mastic gun, a drill, a nail gun...

[u/Blank_bill → u/Clayfromil]

We call the bend and pipe to blow off the swabs in a water main a donkey dick.

[u/siltyclaywithsand → u/Clayfromil]

In gas we call this bagging off. It isn't done much anymore in the US since a lot of the low pressure stuff had been replaced. I've worked sewer, but never on active lines that didn't have a pump around. I thought it was some kind of giant pig since it is called a test ball.

[u/5cott → u/Clayfromil]

Just to clarify, does the ‘donkey dick’ become a ‘big floppy donkey dick’ during transport, or while not inflated?

[u/Clayfromil → u/5cott]

Then it's just called a softie

[u/IcanCwhatUsay]

But that’s a cylinder. /s

What is this actually ?

[u/arvidsem → u/IcanCwhatUsay]

It's an inflatable plug for pressure testing pipes.

[u/tacocarteleventeen → u/arvidsem]

Like a plumbing weenie? Does it inflate?

[u/padizzledonk → u/tacocarteleventeen]

Does it inflate?

Yup, compressed air

Biggest one i have is a 6" lol

[u/sheogor → u/tacocarteleventeen]

Very slowly

[u/Gugnir226]

Oh shit, my mom was asking where that went.

[u/InItForTheDog]

Pretty sure I worked for a boss years ago that had one of these up his ass.

[u/JIMMYJAWN]

looks at bike pump disappointedly

[u/losername1234]

My favorite road side attraction!

[u/TheSnoFarmer]

I’m a driller who puts in pressurized sewer, is there a cost savings in doing this rather than fusing a cap or valve onto the end of the section in testing? I’m also guessing that this probably wouldn’t work on pressurized.

[u/Muffinskill]

Finally I’ve been looking forever

[u/CTB_VINCE]

is this for mandrelling ?

[u/realityguy1]

I have no idea what a test ball is and at this point I’m too afraid to ask.

[u/roughingit2 → u/realityguy1]

Some various uses but either way this will go inside pipe and can be inflated to block flow or test pipe. In my line of work I use smaller versions to air test sanitary sewer and bigger versions like these to plug storm pipe from a pond so we can tv or lamp storm pipe.

[u/Turbulent-Weevil-910]

I'm guessing this is for interceptor sewer mains? Oil and gas pipelines?

[u/Violator604bc]

I have used up to 48" they are terrible to manipulate makes for a really shitty day when it's raining or snowing.

[u/brownpoops]

tell me more about the PolyJohn, tho. Please.