Caulked a joint for the first time

[Chris]

In most Counties here in CA they require an air or water test on my underground sewer lines. I try and air test only because we don't always have access to water where we are working, the districs like to water test by just filling the line and seeing if it settles. When we air test it is at 4 PSI for two hours. At 4 PSI it will shoot a fiiting out of the ground like a canon I have had it happen a few times.

 

[CHRISM]

In most Counties here in CA they require an air or water test on my underground sewer lines. I try and air test only because we don't always have access to water where we are working, the districs like to water test by just filling the line and seeing if it settles. When we air test it is at 4 PSI for two hours. At 4 PSI it will shoot a fiiting out of the ground like a canon I have had it happen a few times.

"Hello Chris",

As You know the 3 - 4 or 6 Inches Water Gauge Pressure that I mentioned in My Post is not as `High` as 4 PSI.

We could Test the Stacks at a Higher Pressure but it is found that these Water Gauge Low Pressures are more than Adequate [and Safer] to ensure that the Stacks are not Leaking Air or Water - and hence not able to allow the escape of any Gases or Bacteria from the Drainage System [except possibly under extreme circumstances].

Obviously when the Sanitary Ware / Wastes and Traps are connected the Trap Seals govern the Pressure that can be used.

Regarding your experience with the Fitting being `Blown Off` at 4 PSI - If you can remember details of any of the examples of this - can I ask approximately what Volume of Air would have been in the Pipework at that time ? - and do you remember if the Weather - Temperature was `Hot` - ?

I ask this out of genuine interest.


Regards,

CHRISM

 

[CHRISM]

Hi CHRISM, Keeping busy I see.

"Hello Mr_David"

I think that I made My first Post on this subject about 2 / 3 Weeks ago - I have just been Replying to some Members who have commented about My Posts since then.

Regards,


Chris

 

[Chris]

"Hello Chris",

As You know the 3 - 4 or 6 Inches Water Gauge Pressure that I mentioned in My Post is not as `High` as 4 PSI.

We could Test the Stacks at a Higher Pressure but it is found that these Water Gauge Low Pressures are more than Adequate [and Safer] to ensure that the Stacks are not Leaking Air or Water - and hence not able to allow the escape of any Gases or Bacteria from the Drainage System [except possibly under extreme circumstances].

Obviously when the Sanitary Ware / Wastes and Traps are connected the Trap Seals govern the Pressure that can be used.

Regarding your experience with the Fitting being `Blown Off` at 4 PSI - If you can remember details of any of the examples of this - can I ask approximately what Volume of Air would have been in the Pipework at that time ? - and do you remember if the Weather - Temperature was `Hot` - ?

I ask this out of genuine interest.


Regards,

CHRISM

120 Feet of 4" SDR 35 PVC pipe Bell x Spigot
3 - 45 bends in the line along with three clean outs.
Clear weather about 70 degrees Fer.

The line held for approx 3 minutes before ejecting the cleanout cap and eight inch round metal lid several feet in the air. That was the first and last time I have seen this happen.

I also know first hand what it is like to cut into an 8" PVC water line that is fully charged at 80 PSI, like a bomb going off and more water then I have ever seen come out of one pipe in a matter of seconds. From cutting to swimming in a second.

 

[CHRISM]

"Hello Chris",

I bet that the Cleanout Cap blowing off was a Surprise !

I was expecting You to write that the Pipe was a much larger Diameter and that the Temperature was Higher - regarding a large Volume of Air within the Sealed Pipe having Expanded from the Heat and causing the Pressure to rise significantly.

Although 120 Feet of 4" Pipe contains quite a lot of Air - at a temperature of 70 Degrees - and after only 3 Minutes - it is surprising that the fitting blew off - and it shows how careful You have to be when sealing a Pipe for Testing.

The cutting into the 8" Water Pipe sounds as if it was `Refreshing` to say the least !

I have seen plenty of Burst Water Mains Pipes - `Fountains` - but never with anyone next to the Burst at the time.

Thanks for replying to My request for the details.


Regards,


Chris

 

[Chris]

On the water line we cut into them to do connections for Fire services. Either we hot tap them with a saddle or do a cut in tee. Usually us as contractors are not allowed to operate city valves or even touch them. On this one we were told it was shut down but there was a misunderstanding on which valve. From then on we make sure that if we don't watch the shut down then we at least check the valve to make sure it is shut.

 

[CHRISM]

On the water line we cut into them to do connections for Fire services. Either we hot tap them with a saddle or do a cut in tee. Usually us as contractors are not allowed to operate city valves or even touch them. On this one we were told it was shut down but there was a misunderstanding on which valve. From then on we make sure that if we don't watch the shut down then we at least check the valve to make sure it is shut.

"Hello Chris",

It is very frustrating when a misunderstanding or error by others causes something like that to happen - especially if it were to happen within a Building !

My Company is not involved in Water Mains Work - in the U.K. this is carried out by Very Big Ground Work & Utility Companies.

There are ongoing Contracts Countrywide for the Renewal of our Water Mains and Mains Gas Distribution Networks - in Many areas the `Old Pipes` were over 100 Years Old !

Regards,

Chris