Apeks Tek 3 1st stage problems

[tstormdiver]

I have a rather perplexing problem with an Apeks Tek 3 1st stage. I use this 1st stage in conjunction with a ScubaPro S600 second stage on my doubles. The right post 1st stage is the problem, the other regulator is fine. They are basic diaphragm regulators. I got them from a friend in Oct. I serviced them back in Dec. The former owner never reported any problems. While in FL, the 2nd stage started lightly free flowing towards the end of the week. It was exhibiting the symptoms of a creeping IP problem, because when I would purge the regulator, the 2nd stage would stop free flowing for about a minute, then slowly resume. When I got home, I checked it out & confirmed the IP creep from 135PSI to over 160, at which point the second stage started leaking as I had observed. I changed out the HP seat & stem O-ring. I set the IP at a solid/ steady 135 psi again. I took the regulator back down to FL in March & by the end of the week, once again, the IP creep & the light 2nd stage free flow was back. I just put another HP seat & stem O-ring & so far, it is steady. Any idea what is going on? Why is it steady, until a week of heavy use, then starts leaking. Each time I service it, I cycle the regulator 300- 400 times to try to make sure the bugs are worked out. I serviced the left post regulator also in Dec. & had no problems. I've looked them both over in comparison & can not see anything obvious. I just can't seem to figure out what may be going on.

 

[Centrals]

Take a look at the valve seat.
Only the FSR can the valve seat(ARCAP) be changed.
Any distinct making on the HP seat?

 

[tstormdiver]

Not exactly sure what you are talking about... Do you mean the HP orifice that the HP seat rests on? I changed out he rubber HP seat twice with the same results.

 

[elan]

I think he means the orifice that is machined in the body. Also did you check the o-ring seating area in the balancing chamber for any marks? You can try to swap the balancing chambers from one post to the other and see if the problem migrates to the other post. If it does that's the chamber problem. If it does not you will rule out the chamber.

Like Centrals said I would check the hard seat (orifice ) for the signs of any marking. It recessed so it's not so easy to see but you still can.

One reason why you have it starting creeping toward the end of the week could be salt water intrusion if you dive salt water. It forms crystals which can prevent the seat from seating properly.

One way you can check what the problems is (but it will require the further rebuild) If you see it creeping , disassemble the LP side, remove the diaphragm and the push pin. Pressurize the reg and drop few drops of water into the orifice. If it starts bubbling there - it's the seat area. Otherwise it's the balancing chamber. IF you drop water into the balancing channel you should see bubbles there.

This is what I did with my Zeagle and Apeks should be similar.

 

[tstormdiver]

Nope not salt water. It has happened whilst cave diving (freshwater). Good idea about swapping internals. I will take a bright light & double check the orifice. I will also check for etching in the balancing chamber. Thanks.

 

[KD8NPB]

Sounds like the volcano orifice might have a flat spot in it.

Use a magnifier and look for any flat spots...it should be damn near a knife's edge around the whole perimeter of the nozzle.

 

[tstormdiver]

Sounds like the volcano orifice might have a flat spot in it.

Use a magnifier and look for any flat spots...it should be damn near a knife's edge around the whole perimeter of the nozzle.

I am not saying it is or isn't, but if that were the problem, shouldn't it leak or have the IP creep all the time? This regulator is rock solid in it's IP, until towards the end of a week of hard diving. That's what is so weird.

 

[Jim Lapenta]

As the seat gets cycled it will start to groove. At first there might be just enough play in the seat material for the entire orifice face to make contact. As it gets compressed though at some point the flat spot will not compress as much as the seat under the knife edge and then you'll start to see the creep. I would suspect that this could be the issue since you've used two different seats. One could have just been a wonky seat. Two - the chances of that go down considerably. We get this with the check valves and connections in our HP (87,000psi) waterjet system as well. Coning the mating areas needs to be precise as any flat spot will eventually turn up as a leak that you can't snug up enough to stop. The angle on the cone will eventually result in an uneven pressure on the mating surfaces and any flat or dull spots will start to show.

Sent from my DROID X2 using Tapatalk 2

 

[tstormdiver]

Thanks Jim, That makes some sense. I am headed back down to FL in a couple weeks,... I will look at them after I get back (will take a couple spare 1 stages,... just in case)

 

[Centrals]

If it is the valve seat(HP orifice) then there is not much you can do about it unless it is the FSR(1st stage).

Anyone know a good method to polish it?