all right I'm going to now demonstrate the common failure simulations that you
might be given to you when you're taking your Washington Department of Health
backflow assembly test exam your practical exam and I'm going to do this
on a double check valve assembly so I'm going to show you the common things that
they could possibly throw at you while you're testing and double check valve
assembly so I'm going to you know I'm going to notify identify inspect and
observe when I go to test my double check valve assembly I'm gonna make sure
I'm testing the double check valve assembly which happens to be this one
right here says so on the tag so I know that that's my double check valve
assembly it looks very similar to the RP but it does not have a relief valve
that's another clue and it also has arrows cast on the body to tell me what
my direction of flow is so I've got test cock one test cock to test got three
tests cock for shutoff valve number one shutoff valve number two so the first
thing I'm gonna do is I'm gonna go ahead and flush my test cocks so flush test
cock number one flush test cock number two flush test cock number three flush
flush cock number four again I like using a sight tube so I'm going to go ahead
and put my sight tube on test cock number three and I'm gonna fill the
sight tube full of water
alright then I'm gonna put my compensating valve on task cock number
two and again I like pointing my compensating valve on port shutoff valve
number one I'm gonna be using a Midwest five valve kit again the only hose I
need is the high side hose it's the only hose I have hooked up and so I'm gonna now hook
my high side hose up to the compensating about the other thing to be aware of if
you're using one of these buy one of these types of kids is that you do not
want to cover up your other connections here because this connection
specifically needs to be opened up to atmosphere if you do not if you put your
hand over it it'll give you a an invalid reading or give you a bad reading so I'm
going to open up test cock number two if I can find the slot and that'll drive my
gauge to the upper end you may have noticed that gurgles and spit some water
out of this particular port that's fine it's supposed to do that next I'm going
to purge some water out of the test kit make sure my hose doesn't have any air
in it make sure I got the ear out of the test kit so I'm running water out of the
test kit by opening the high side bleep valve when I close the high side bleep
valves all right and at this point I'm going to close shut off out number two
I'm gonna elevate my test kit so that the center line of my test kit is even
with the sight tube I'm gonna close shut off valve number one I'm gonna take
my screwdriver and open up test cock number three and observe what's
happening in the sight tube - well I would have thought by now that the flow would
have stopped going in the site tube so I still have flow continuing through the
site tube so I have water coming into the body of the assembly from somewhere
and so now I need to determine where it's coming from and the way you
determine that is now I'm going to open up my compensating valve and see what
happens so I'm gonna open up my compensating valve and I notice that as
I open up my compensating valve more and more my flow and my sight tube is
reduced and the flow from my compensating valve continues to go now
the reason why I like the pointed at shutoff valve number one is if it
continues to flow out of my compensating valve that reminds me that my leak is
shut off out number one so in this case I have a leaking shutoff
valve number one okay if it were shutoff valve number two leaking well first of
all the check valve would have had to fail and then if this check valve is
working the water would stop so I have a leaking shutoff valve number one and the
other thing you can observe is when I close my compensating valve the flow
increases out of my sight tube alright so there's that's what a leaking
shutoff valve number one it looks like if I were taking the exam I would say
Proctor I've got a leaking shutoff valve number one which case the Proctor would
go problem has been corrected now you would need to back up and retest
so I would close my test cock to my sight tube
I would re pressurize everything you know then I would elevate isolate and
test and continue on with the test well for the sake of time I'm going to show
you another simulation so excuse me I'm ready to test my check valve number one
here so I'm gonna open up my test cock and watch my gauge and I'm looking at
the monitor so I can kind of see what's going on and lo and behold my gauge has
dropped below one PSI d remember the minimum value is 1 psi D so since this
the value is below one psi D in fact now it's zero that tells me that I have a
failed check valve so again if I were taking the exam I would say Proctor I
have a failed check valve number one in which case the Proctor would say problem
has been corrected again you would back up a step and you would back up a step
by closing the test cock repressurizing the assembly and continuing on all right
so again I'm gonna simulate another fault for you so I'm getting ready here
to test my assembly so I flushed the test cocks I've done all that I'm gonna
elevate I'm gonna reach down and isolate I'm gonna test Check valve number one so
I'm gonna open up the test cock oh wait a minute I haven't opened up the test
cock yet I haven't done anything yet and I've
noticed that the pressure and my gauge is dropping well what that tells me is
is that water's leaving the assembly and essentially what it's really indicating
to me and what I'm going to say in my mind is that I bet I've got a leaking
shutoff valve number two okay so what's happening is is that pressures
being relieved out of the body by going past check valve number two and out
shutoff valve number two so I would essentially have I would suspect but I
will confirm here in a minute that I have a leaking number two shutoff valve
with flow okay now my gauge is still above one psi D I can still perform the
test like check valve number one so I'm going to open my test cock to my sight
tube and I'm gonna keep an eye on it and I'm gonna wait for the water to stop
flowing in the sight tube it's still rising a little bit and for my gauge to
stabilize alright it stopped flowing out and I have a value of two point zero psi
D so check valve number one holds tight at two point zero psi D okay in this
case now what I'm gonna do is I'm gonna set down my gauge I'm gonna move my test
equipment down but I'm keeping in the back of my mind that I suspect that I
have a problem with shutoff valve number two so I'm gonna go ahead and move my
test equipment down
all right again I'm gonna make sure that my sight tubes full of water
oops helps if you turn shutoff valve number one on so you have pressure
pressure it also helps if you close the test cocks you know these are not things
that would fail you they're just things that get things wet like myself so I'm
gonna close shutoff valve number two or open shut off album number one so sorry
about that I am going to fill my sight tube full of water I'm going to open up test cock
number three which we pressurized my gauge again I'm going to purge my gauge
make sure there's no air in the gauge I'm gonna elevate my test kit to the
level of the sight tube so the centreline is elevated to the level of
sight tube I'm gonna close shot off valve number one and I've noticed that
the same things happening where my pressure is dropping in my gauge all
right I can now open up test cock number four and I observe that the water is
draining out of my sight - well the only way the water is going to drain out of
the sight tube in this case is that this shutoff valve is leaking and I got flow
downstream now you notice I lowered my gauge with level the water okay in the
real world you can get a valid reading for check valve number one in this case
if you lower the gauge to where the water is draining out which would be the
elevation of this discharge piping and in which case I get a check valve check
valve number two value of 2.0 psi D in the exam what you would do is you
would say Proctor I have a number two shutoff valve that is leaking with flow
downstream in which case the Proctor would say problem has been corrected and
you would back up and retest I'm gonna remember this time to close my test cock
so I would back up by closing my test cock I would open shutoff valve number
one I would refill my sight tube full of water to be on the safe side I'm gonna
reap urge the assembly and I'm gonna elevate isolate and test check about the
number two and again when the water stops blowing and the gauge is
stabilized you can read a value and I get a value of 2.2 PSID a little bit
different than one I got before when I lowered my gauge down to here but it's
within the accuracy of the gauge so check valve number two passes with a
value of 2.2 psi D okay so now you can close the test cock and continue
on with the test okay well to show you some other simulations that could
possibly happen while you're doing the assembly so I've already tested check
valve number one I've moved on to check valve number 2 my
hose again is wrapped up on me okay I'm gonna fill my sight tube full of
water I'm gonna turn on test cock number three I am going to purge my assembly
I'm gonna setup another simulation all right so I'm
gonna elevate isolate and test so I'm going to open up test cock number four
all right again water continues to flow from the sight tube so that tells me
that water is entering the body of the assembly from somewhere and I need to
determine where again you're gonna go over to your compensating valve which
i've pointed at shutoff valve number one and i'm gonna open it up and see what
happens well when I open it up well I notice my flow goes down a little bit
but the key thing is water keeps flowing out of the compensating valve toward
shutoff out number one so that tells me shutoff valve number one is leaking now
I used to think this was Bogus but it really isn't because remember between
check valves you're opening and closing shutoff valve number one you could
potentially get something like a piece of teflon tape in the ball valve between
when you test the assemblies so it is possible that you could it doesn't leak
when you test check valve number one and could possibly leak when you do check
valve number two so again I would say Proctor I have a leaking shutoff valve
number one and again I can reconfirm by when I close the compensating valve
water the amount of water that comes out of the sight tube increases all right so
I've tilt Proctor I've got a leaking shutoff valve number one he's gonna go
problems been corrected and again you would back up by closing the test cock
opening shutoff out number one and continuing on with the test
alright so now I'm going to show you another simulation so again I'm gonna
purge my test kit I'm gonna elevate
isolate and test by opening test cock number four so I open test cock number
four and I watch my gauge I'm watching it in the monitor and lo and behold it's
gone below zero or it's not gone below zero it's gotten below one to zero so my
check valve number two is failed so I would say Proctor check valve number two
is failed Proctor would say problems been corrected again you're gonna back
up again you're gonna close the test cock open up shut off out number one to
repressurize the assembly and move on alright so I've got one more simulation
I need to do for you so again I'm getting ready to test check valve number
one my side tubes full I've purged my assembly I'm gonna elevate isolate and
test so I'm going to open up my test cock number four and observe what
happens
so again water continues to flow from the assembly so I've got water coming in
to figure out where I'm going to open up my test
or excuse me my compensating valve in this case my compensating valve
actually stops flowing water okay so what that tells me is the waters not
coming from shutoff valve number one through here it's actually coming
through shutoff valve number two with back pressure
it's the check valve and out through the side tube so I have a leaking number two
shutoff valve with back pressure all right in which case the Proctor will say
problems been corrected and I would close my compensating valve closed my
test cock open up shutoff valve number one I would purge my assembly just to be
on the safe side I would elevate isolate and test
alright wait for the water to stop flowing out of the sight tube still
rising slightly and the gauge is stabilized and I have a value of 2.1 psi
D so check valve number 2 holds tight a 2.1 PSI d
Set my equipment down close test cock number 4
test cock number for closed test cock number 3 slowly open shutoff valve
number 1 slowly open shutoff valve number 2
remove my test equipment and I would be done and now I'm done testing the double
check valve assembly and I would fill out my test report legibly accurately
and completely alright so that would be the end of doing my double check valve
assembly in which cases I would say Proctor I'm done testing the double
check valve assembly and hopefully he will say which assembly would you like
to test next