# back flow test



## revenge (Jun 30, 2011)

Well guys took my forty hour corse and took my hands on test today and passed, with flying colors.:thumbup: Tommorow i take the written exam hundred questions  god willing i pass. After i pass the test i will be in the market for a good test gauge. Midwest probaly cause thats what i trained on well my question is where is a good site to find it a good cost thanks in advance.


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## user7551 (Oct 21, 2011)

ebay to start , or if your in the north texas area check out macarthur gauge over in hurst tx


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## DesertOkie (Jul 15, 2011)

Since it's hard to find a Barton now, I like the Midwest 845 big dial easy to see. 

If you do any DCV get their DCV set up with sight tube ect. I didn't need one until recert then I had to pay super fast shipping so I would have it in time.


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## revenge (Jun 30, 2011)

In class they showed us how to make a sight tube and a compensatiing valve was pretty cool and most the stuff you can find on your truck


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## Mississippiplum (Sep 30, 2011)

Congrats, good luck on the test tomarrow!

sent from the jobsite porta-potty


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## DesertOkie (Jul 15, 2011)

revenge said:


> In class they showed us how to make a sight tube and a compensatiing valve was pretty cool and most the stuff you can find on your truck



That's what I used in the field. They made a stink about having nice stuff. I think it was because guys were just slipping rubber tubes over the test cock for their test. They would fail and be pissy because they had to wait 3 months to retest.


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## TPWinc (May 30, 2011)

There's probably some place closer to you, but I use Instument Specialist Inc. in Sanford Florida. Model 835 or 845 are great guages. Both are the same gauge but different case. Don't forget to order the speed fittings!


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## MarkToo (Dec 17, 2011)

Guys are doing the sight tube part in the field? Really?


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## user7551 (Oct 21, 2011)

double check here has to be tested under the newest usc standards which requires a site tube.


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## SewerRatz (Apr 25, 2009)

When testing a double check, why do you need a sight tube? I have been always testing it with direction of flow. Even took a refersher course down state and they never mentioned testing with a site tube.


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## TPWinc (May 30, 2011)

SewerRatz said:


> When testing a double check, why do you need a sight tube? I have been always testing it with direction of flow. Even took a refersher course down state and they never mentioned testing with a site tube.


The sight tube is only really needed, when doing a direction of flow test on a double check valve, when the valve is underground. It's used to bring the water level up to the guage height. You do the same test on a PVB but are not required to use the tube because they are always above ground. You must have the guage at the water level of what you are testing when doing a direction of flow test. Otherwise you will be measuring the head of water in the hose along with the check pressure.


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## MarkToo (Dec 17, 2011)

TPWinc said:


> The sight tube is only really needed, when doing a direction of flow test on a double check valve, when the valve is underground. It's used to bring the water level up to the guage height. You do the same test on a PVB but are not required to use the tube because they are always above ground. You must have the guage at the water level of what you are testing when doing a direction of flow test. Otherwise you will be measuring the head of water in the hose along with the check pressure.



A differential gauge will give you the same test - head pressure isn't relevant as it's balanced on both the high side and low.

To me it seems it's the same as measuring your tire pressure with a good gauge to see if the air pressure is correct then, using the sight tube is akin to giving the tire a good kick just to be sure.

School me if I'm wrong here but, I don't even own a sight tube...


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## TPWinc (May 30, 2011)

MarkToo said:


> A differential gauge will give you the same test - head pressure isn't relevant as it's balanced on both the high side and low.
> 
> To me it seems it's the same as measuring your tire pressure with a good gauge to see if the air pressure is correct then, using the sight tube is akin to giving the tire a good kick just to be sure.
> 
> School me if I'm wrong here but, I don't even own a sight tube...


 
If you are doing a differential test on a DC how do you know you a reading static differential? You don't unless it's a dedicated fire backflow and even then you are not 100% sure. That's why we do a direction of flow test with an open test cock or short tube in conjuction with the high hose on the differential guage, so you can see the water stop moving. 

As for the Sight Tube by itself... It is far more accurate than any guage. They use them to calibrate your guage! 

One of the problems on this thread is that everyone is confusing "sight tube" with "short tube". The short tube is used with the guage. The sight tube is used by itself. The sight tubes are usually about 42" to 48" long where the short tubes are about 12".


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## ILPlumber (Jun 17, 2008)

Is he referring to a dual check rather than a double check?

I test dual checks with a sight glass......

Double checks (obviously) are tested with a differential gauge for the 1st and 2nd check tests as well as the outlet shut-off test.


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## bizzybeeplumbin (Jul 19, 2011)

I have a midwest 845 5 valve. I am a new tester to the area and don't test enough to memorize the RP, so I made this up to keep me fresh. I came home today at lunch to finish it. I drilled holes in the 2x4 so I could drain it.


I use the sight tube and compensating tee for double checks, this is the way I was taught.











If you dont use it you lose it. I am making one for a double check also.


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## TPWinc (May 30, 2011)

ILPlumber said:


> Is he referring to a dual check rather than a double check?
> 
> I test dual checks with a sight glass......
> 
> Double checks (obviously) are tested with a differential gauge for the 1st and 2nd check tests as well as the outlet shut-off test.


 
Sorry I meant DCVA. Brain fart!:laughing:

Here's a video of what I mean when I say direction on flow test.


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## SewerRatz (Apr 25, 2009)

TPWinc said:


> Sorry I meant DCVA. Brain fart!:laughing:
> 
> Here's a video of what I mean when I say direction on flow test. DCVA backflow test - YouTube


 That is a whole lot of work to test double check. Why not just do a direction of flow test using the high and low side of the differential gauge.


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## ILPlumber (Jun 17, 2008)

What a pain in the butt that looks like.

That is no more conclusive than a DOF test.

It just takes 5x longer......


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## user7551 (Oct 21, 2011)

We have to test double checks like that here in texas , because we are under usc 10th edition , the 9th edition was alot easier


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## TPWinc (May 30, 2011)

SewerRatz said:


> That is a whole lot of work to test double check. Why not just do a direction of flow test using the high and low side of the differential gauge.


With the high and low hose it's a differential test. With a differential test a 0 reading on check #1 could actually be a bad #2 check with backpressure from a leaking #2 shut off, and the #1 check is fine. 

If you are checking a DCVA using the differential method you must verify that the #2 shut off is holding and your readings are static. How are you doing that? The only way I can figure you can correctly verify this is to put backpressure on #2 check and see if it holds. That would add a few steps to the differential method.

The video makes it look like more work than it really is. I don't use the compensation tee or the short tube if the test cocks are on top and I can center the guage to the top of the downstream test cock.


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## bizzybeeplumbin (Jul 19, 2011)

saw this on ebay

http://www.ebay.com/sch/i.html?_nkw...machine&_osacat=0&_trksid=p3286.c0.m270.l1313


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## Redwood (Sep 8, 2008)

I assume you were talking about this item...

http://www.ebay.com/itm/Mid-West-Instrument-Backflow-Test-Kit-845-5-FREE-Carrying-Case-5-Yr-Warranty-/270885259673?pt=LH_DefaultDomain_0&hash=item3f12050999#ht_2534wt_1042

1/2 an hour later it was on page 3...


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## Tommy plumber (Feb 19, 2010)

I use the Midwest model 830. 

http://www.backflowtestkits.com/products/830.html


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## bizzybeeplumbin (Jul 19, 2011)

Redwood said:


> I assume you were talking about this item...
> 
> http://www.ebay.com/itm/Mid-West-Instrument-Backflow-Test-Kit-845-5-FREE-Carrying-Case-5-Yr-Warranty-/270885259673?pt=LH_DefaultDomain_0&hash=item3f12050999#ht_2534wt_1042
> 
> 1/2 an hour later it was on page 3...




Yes, thanks, I messed that one up pretty good, lol! :thumbsup:


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## revenge (Jun 30, 2011)

o forgot to tell everyone i passed both tests sent out my application with my fee and now all i have to wait for is for it to come in the mail and get me a gauge and i will be ready


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## Mississippiplum (Sep 30, 2011)

revenge said:


> o forgot to tell everyone i passed both tests sent out my application with my fee and now all i have to wait for is for it to come in the mail and get me a gauge and i will be ready


Congrats, good job man.

sent from the jobsite porta-potty


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## Redwood (Sep 8, 2008)

Congrats Revenge! :thumbup:


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## SewerRatz (Apr 25, 2009)

Give these guys a call. Ask for Rick, he can give you a great deal on Midwest gauges. http://testgauge.net/


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## revenge (Jun 30, 2011)

i found a midwest -5 for 669.17 free shipping any body find one for cheaper any where btw new from factory with the five year warranty


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## bizzybeeplumbin (Jul 19, 2011)

revenge said:


> i found a midwest -5 for 669.17 free shipping any body find one for cheaper any where btw new from factory with the five year warranty


There was the one on ebay for 699. with 5 year warranty. Redwood re-posted the link for me. search ebay, its on there and still available.

That looks like a great deal to me.


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## revenge (Jun 30, 2011)

that same guy has a web site if you look through his post go to his web site and he sales the same one for 669.17 he says its cheaper on his site since he dont have to pay for any extras like he does on ebay but just wanderin if any body has found cheaper


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## DesertOkie (Jul 15, 2011)

If you can't find anything I'll sell ya a watts tk9 for $50 + ship if ya want. I bought it from a pawn shop for a little more but never had it calibrated, I'm not sure it even works. But like I said if ya want to roll the dice. I like my midwest 845 and new is always better.


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## TraTech (Jan 22, 2012)

I have a watts tk99e
Got it on a fire sale for $899, I like it.


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