Help,, my pipe exploded !!!

[JoyfulNoise]

Sorry it happened to you and glad no one was anywhere near the equipment when the explosion happened. PVC shrapnel can kill just as easily as metal. This is a classic SWG explosion. The SWG creates both hydrogen gas and chlorine gas. If the pump isn’t running a bubble of gas will build up in the highest part of the plumbing. Chlorine/hydrogen gas mixtures are incredibly explosive and can self-detonate (no ignition source needed). Even just a few minutes of gas production before the pump turns on can create a huge bubble of gas. This is why an SWG should NEVER come one before the pump does and why a flow switch is a vital safety feature. Most automation systems ensure that this can never happen. Unfortunately, old school mechanical timers have no way of preventing this if they are not accurately timed and maintained. Power outages and slight mechanical/electrical difference between timers can easily cause them to drift out of sync.

And expensive lesson learned but thankfully one that didn’t involve a trip to the hospital … or the morgue.

 

[proavia]

Moving forward, instead of making the pics smaller, turn off HDR on your phone camera. That should allow easy upload of phone camera images.

Glad no one was injured or worse.

I agree with @JoyfulNoise - SWG was on before pump came on - boom.
Check the times on the timers frequently.
A functioning flow switch and ensuring the pump starts prior to the SWG starting and the SWG stops prior to pump stopping is vitaly important.

 

[Onmarko9]

Sorry it happened to you and glad no one was anywhere near the equipment when the explosion happened. PVC shrapnel can kill just as easily as metal. This is a classic SWG explosion. The SWG creates both hydrogen gas and chlorine gas. If the pump isn’t running a bubble of gas will build up in the highest part of the plumbing. Chlorine/hydrogen gas mixtures are incredibly explosive and can self-detonate (no ignition source needed). Even just a few minutes of gas production before the pump turns on can create a huge bubble of gas. This is why an SWG should NEVER come one before the pump does and why a flow switch is a vital safety feature. Most automation systems ensure that this can never happen. Unfortunately, old school mechanical timers have no way of preventing this if they are not accurately timed and maintained. Power outages and slight mechanical/electrical difference between timers can easily cause them to drift out of sync.

And expensive lesson learned but thankfully one that didn’t involve a trip to the hospital … or the morgue.

Makes alot of sense.. thanks very much for the help.. I don't have a flow switch on my salt cell unfortunately

 

[Onmarko9]

Did you look at the link to the thread Explosion near the SWG that Allen posted? Looks very similar.

I have no idea what a 'gas lock' is ----

I did there.. thanks alot for you help . Really appreciate it

 

[ajw22]

I don't have a flow switch on my salt cell unfortunately

You said you have a Jandy SWG. What model?

Aquapure, TruClear, Nature2 Fusion all have flow switches.

@PoolGate please confirm the Jandy Nature2 Fusion has a flow switch?

 

[Onmarko9]

You said you have a Jandy SWG. What model?

Aquapure, TruClear, Nature2 Fusion all have flow switches.

@PoolGate please confirm the Jandy Nature2 Fusion has a flow switch?

I have the True clear Jandy

 

[kul]

@Onmarko9 this is terrifying. I’m happy no one was hurt. I look forward to seeing what is done to remedy this so it doesn’t happen again.

 

[ajw22]

I have the True clear Jandy

The TruClear has a flow sensor and the Installation Manual says:

The power pack must be interlocked/interconnected with the pool pump motor power source to ensure that the chlorinator only operates when the pool pump is operating. The flow sensor feature of the Jandy TruClear is intended to be used as a backup only and should not be used as the sole source of flow detection.

and

To avoid property damage, serious injury or death, do
not operate the electrolytic cell without water circulation
or if cell housing is damaged or improperly assembled.
A buildup of flammable gases which can result in
FIRE OR EXPLOSION. The power pack must be
interconnected with the pool pump motor power
source to ensure that the chlorinator only operates
when the pool pump is running. The flow sensor
feature of the Jandy TruClear is intended to be used
as a backup only and should not be used as the sole
source of flow detection.

and

The Jandy Pro Series chlorine generating device
must be installed outdoors only. The cell must be
installed horizontally with the cord facing upwards to
avoid buildup of flammable gases which can result in
FIRE OR EXPLOSION.