Backscatter airlock pump

I have the above system and it has recently started being difficult to achieve the vacuum. I *can* get there but it seems harder and harder to do.

Diagnosis tells me the port and gauge will hold a vacuum. It seems to be the pump releases the vacuum the second I stop drawing on it.

This article suggest you can ‘overrun’ the pump if used too vigorously. What isn’t clear is if it’s a permanent failure or not. Slow/fast doesn’t seem to make any difference, so I’m guessing it’s broke.

https://wetpixel.com/articles/review-backscatter-airlock-vacuum-integrity-check-system

Has anyone experienced this and, b) has anyone bought a VacuVin pump (from Amazon etc) to successfully replace the Backscatter one? I’m UK based so don’t want to need a US replacement

Thanks

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5 hours ago, OwenF said:

 

I have the above system and it has recently started being difficult to achieve the vacuum. I *can* get there but it seems harder and harder to do.

 

Diagnosis tells me the port and gauge will hold a vacuum. It seems to be the pump releases the vacuum the second I stop drawing on it.

 

This article suggest you can ‘overrun’ the pump if used too vigorously. What isn’t clear is if it’s a permanent failure or not. Slow/fast doesn’t seem to make any difference, so I’m guessing it’s broke.

 

https://wetpixel.com/articles/review-backscatter-airlock-vacuum-integrity-check-system

 

Has anyone experienced this and, b) has anyone bought a VacuVin pump (from Amazon etc) to successfully replace the Backscatter one? I’m UK based so don’t want to need a US replacement

 

Thanks

 

 

Sent from my iPhone using Tapatalk

 

I believe it is a straight piston pump, so very little could go wrong with it - how does it connect to the gauge?  it looks like a press-on rubber fitting.  These systems typically rely upon a check valve to prevent air from entering.  From the review it indicates that attaching the gauge without the pump will release the vacuum - so this indicates the check valve is located within the pump attachment and this would be where the problem lies.

I don't see a vacu-vin working as you need an airtight attachment to the hole in the gauge - unless a vacuum wine stopper forms a tight seal in the hole.  You can't transfer the rubber assembly at the end of the pump over the a new pump as the rubber assembly is where the problem lies if I have interpreted the construction correctly. 

Now if a vacu-vin stopper fits in the hole tightly it might a solution - you rely on the pinch valve in the stopper to hold the vacuum.  If it doesn't - just use it to keep your wine fresh.

I suspect there is something like the vacuum wine stopper pinch valve inside the end of your pump - you might have some dirt in there or the valve material has lost flexibility preventing it from working as designed.

The backscatter pump is a Vacu-vin pump, as it’s written on the handle.

It looks like they normally come in two parts 1 - the pump 2 - individual bottle stoppers. Backscatter looks like they’ve ‘permanently’ sealed a stopper into the pump by gluing a piece of rubber/heat shrink around the two components to make it a permanent system.

Correct, the check valve is in the pump system, not the gauge. Hence I’d expect if I suck through the bottom of the pump that it would hold vacuum. But it doesn’t.

I suspect the check valve is damaged. So sounds like question is whether I can replicate backscatters retrofit of the two Vacu-vin components


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@OwenF
I think I may be misunderstanding you here but I have just tried "sucking" two pumps and they both don't hold a vacuum when I do so. I can confirm that they both create a vacuum in a housing fine when required. 

My guess is that the leak is on the interface between the pump and gauge unit. The good news is that other brands of pump work fine with the Backscatter system. I have never tried the Vacuvin ones, but have used Nauticam and Seacam. I can lend you one for troubleshooting if you need. 

Adam

2 hours ago, OwenF said:

The backscatter pump is a Vacu-vin pump, as it’s written on the handle.

It looks like they normally come in two parts 1 - the pump 2 - individual bottle stoppers. Backscatter looks like they’ve ‘permanently’ sealed a stopper into the pump by gluing a piece of rubber/heat shrink around the two components to make it a permanent system.

Correct, the check valve is in the pump system, not the gauge. Hence I’d expect if I suck through the bottom of the pump that it would hold vacuum. But it doesn’t.

I suspect the check valve is damaged. So sounds like question is whether I can replicate backscatters retrofit of the two Vacu-vin components


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If a wine vacuum stopper is a tight fit in the gauge it should work just like it does in a wine bottle and be held in place by the vacuum and you probably would not need to attach the pump.  You would need to remove the stopper or squeeze it like you do a wine bottle to release the vacuum.

13 minutes ago, adamhanlon said:

@OwenF
I think I may be misunderstanding you here but I have just tried "sucking" two pumps and they both don't hold a vacuum when I do so. I can confirm that they both create a vacuum in a housing fine when required. 

My guess is that the leak is on the interface between the pump and gauge unit. The good news is that other brands of pump work fine with the Backscatter system. I have never tried the Vacuvin ones, but have used Nauticam and Seacam. I can lend you one for troubleshooting if you need. 

Adam

Adam this doesn't seem to fit with Owen's description and the description in the review linked above of the system.  The review specifically states that attaching the gauge without the pump will release the vacuum which means the check valve (one-way valve) must be in backscatter pump.  I have a Nauticam pump and it is just a cylinder with a plunger and a nozzle to attach and is not gas tight - it relies upon a dynamic seal to pump air out of the housing and the vacuum is held by the vacuum valve in the Nauticam system, not by the pump.

Unless I am missing something the backscatter system needs a check valve in the pump to work.

The two parts of a housing's vacuum system, the housing vacuum device and the pump, each has its own air check valve. The check valve in the pump allows the piston to remove the air from the housing and then expel it, while keeping the outside air from returning; the check valve in the housing vacuum device does the same while the pump is cycling and when it is removed.

The check valve of my electric vacuum pump lost its seal, I replaced it with a low cost pump from eBay, and it works fine:  
https://www.ebay.com/itm/324186907552?hash=item4b7b0ba3a0:g:MTAAAOSw-m1ezMI5.  

One can make one's own by adding a click switch and a 9V battery in a small plastic box. Or one can use a small hand pump, such as a brake bleeding pump:                                                                                               https://www.ebay.com/itm/384478800046?               hash=item5984b8e8ae:g:mC4AAOSwaV9hgN-G 

Thanks for everyone’s input. I bit the bullet and investigated intrusively.

As suspected, the backscatter pump is in fact a Vacu-vin pump with wine stopper permanently connected using some heavy duty heat shrink:

What surprised me was to find the stopper section is properly functioning. Looking inside the pump it appears there is a damaged seal (without looking back, I think one person suggested this):

Not sure if this is what the article described as ‘overrun’, I’d say more heat damage induced from too vigorous pumping (tee-hee).

Still not clear why it can’t hold vacuum but I’m going to replace the pump (£12 from Amazon) to rule it out.

There is a clicking mechanism in the pump the prevents over-vacuuming. New suspicion is that this is the cause, as it ‘clicks’ on every pump from fresh start when on the housing.

The saga continues!

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