Scubapro 109/156 Balanced Adjustable 2nd-stage adjustment knob 'adjustment' ?

[scubafanatic]

Hello, I recently had a large number of 109/156's and MK 5's completely upgraded/serviced (Thanks Robert!) and I was advised the 2nd-stage adjustment knobs would likely need to be adjusted once the seats are broken in. Well, it definitely appears I need to make said adjustments !

I'm starting to assemble my regs (yesterday assembled (1) MK 5 with (2) 109's upgraded to balanced adjustable, hooked it up to a tank, (as I was told I needed to assemble my reg sets and leave them pressurized overnight to complete the 'break-in', and the very moment I pressurized the reg set, the 2nd stages are free flowing. (one 109 free flows unless it's fully cranked down to the max, the other free flows until it's cranked down half way to the max) I was told I'd likely have to do my own orifice adjustments to fine tune everything, and I barely know what this means ?

As directed, I left the 2nd-stages 'cranked down' for a few days to help break in the seats (about 5 days), unpressurized, sitting in the box (they were shipped to me fully cranked down). They were then all fully uncranked down to relieve seat pressure and left in the box. Now I've assembled 1 full reg set, and am assembling set # 2 now. I've got enough 109/156's and MK 5s to assemble at least 5 full sets ( 1 'first' and 2 'seconds'). So I suspect I'll need to have a bunch of 'seconds' adjusted.

I have limited tools (and even more limited reg repair experience). I do have the Vance Harlow Reg repair book, and I've visited Scubatools.com and saw items that might be useful:

https://www.scubatools.com/p-543-scubapro-balanced-chamber-tool.aspx

I'm debating just letting the dealer handle it, but if it's very easy for someone to make one's own adjustments I prefer to do it myself. (I'm willing to consider making minor adjustments myself, even if I never graduate to doing my own overhauls.)

So, how big a deal is it to do it myself, what good tools will I need, and where are the 'directions' on how to do this ?

Thanks,

Karl

 

[redacted]

The adjustment is very simple. It would be nice to have an IP gauge but not really necessary when you are confident the 1st stage is OK. Only tool needed are a wrench to remove the 2nd stage from the hose and a screwdriver. Would you like to do this here, via PM, or by phone?

 

[scubafanatic]

The adjustment is very simple. It would be nice to have an IP gauge but not really necessary when you are confident the 1st stage is OK. Only tool needed are a wrench to remove the 2nd stage from the hose and a screwdriver. Would you like to do this here, via PM, or by phone?

Hi awap,
I do have an IP gauge, I'm pretty confident that's OK (I havent actually checked the IP, but I requested Robert (couv) set them all at 135 PSI) . I have adjustable wrenches for stage/hose removal. I do have some basic assorted screwdrivers, not organized by size unfortunately so don't know if I have the needed size or not. I'd hate to damage the orifice innards with wrong size or bad technique but if it's pretty simple I'll give it a try. Can you post on the thread the instructions ?

Thanks in advance,

Karl

---------- Post added July 20th, 2014 at 06:10 PM ----------

 

[redacted]

It would be very difficult to damage the orifice. With a nice clean 2nd (like yours) I use a small flat tip screwdriver and only engage one side of the slot in the orifice.

Important: When you turn the orifice, the purge must be depressed.

Set the user adjustment know all the way out. Remove the hose, depress the purge, and turn the orifice about 1/4 turn inward (tighten). Reinstall the hose (finger tight) and see if it leaks. If it still leaks, repeat. If 2 such adjustments don't stop the leak, let's think a bit more before we continue.

Once the leak is stopped, remove the hose, depress the purge, and turn the orifice about 1/12th turn outward (loosen). Check for leak. If it leaks, I leave it if the leak is stopped by not more than one turn of the adjustment knob. That is not the normal procedure but your reg will sure breath well. If it does not leak, repeat one more outward turn. If that does not stop the leak, then less than one turn on the adjustment knob should. Again, if there are any surprises, we need to think some more.

Depress the Purge. Remember to tighten the hose when finished.

Good luck.

 

[scubafanatic]

It would be very difficult to damage the orifice. With a nice clean 2nd (like yours) I use a small flat tip screwdriver and only engage one side of the slot in the orifice.

Important: When you turn the orifice, the purge must be depressed.

Set the user adjustment know all the way out. Remove the hose, depress the purge, and turn the orifice about 1/4 turn inward (tighten). Reinstall the hose (finger tight) and see if it leaks. If it still leaks, repeat. If 2 such adjustments don't stop the leak, let's think a bit more before we continue.

Once the leak is stopped, remove the hose, depress the purge, and turn the orifice about 1/12th turn outward (loosen). Check for leak. If it leaks, I leave it if the leak is stopped by not more than one turn of the adjustment knob. That is not the normal procedure but your reg will sure breath well. If it does not leak, repeat one more outward turn. If that does not stop the leak, then less than one turn on the adjustment knob should. Again, if there are any surprises, we need to think some more.

Depress the Purge. Remember to tighten the hose when finished.

Good luck.

Thanks again! I'll give it a try and see if I encounter any issues or additional questions.

Karl

---------- Post added July 20th, 2014 at 10:34 PM ----------

OK, examining orifice opening. I see a sort of slot, which actually appears angled, which has me worried about scratching the air barrel. On scubatools I see:

https://www.scubatools.com/p-532-orificevalve-t-handle.aspx

I wonder if this tool would be helpful for my needs and help prevent me from slipping and scratching the air barrel ?

This tool doesnt appear to fit into the orifice slot, like a screwdriver would, it appears to get pushed down into the small hole at the center of the slot (per the schematic @ Scubatools) so if this is the case, how would this tool get the bite or traction to actually be able to turn the orifice ?

also saw this stubby screwdriver:

http://www.scubatools.com/p-417-14-stubby-screwdriver-wiha.aspx

 

[Nemrod]

This tool makes it easy:

Shop Online

And this one is useful too:

Shop Online

It is fairly common to set these regs so that when the knob is full out they may very slightly leak. I personally prefer them not quite to that point but on the edge of doing so.

You might want to check and see if it is the diaphragms pressing on the levers once installed and tightened down. If so, this is a lever adjustment, please do not bend the levers to account for this.

N

 

[redacted]

Thanks again! I'll give it a try and see if I encounter any issues or additional questions.

Karl

---------- Post added July 20th, 2014 at 10:34 PM ----------

OK, examining orifice opening. I see a sort of slot, which actually appears angled, which has me worried about scratching the air barrel. On scubatools I see:

https://www.scubatools.com/p-532-orificevalve-t-handle.aspx

I wonder if this tool would be helpful for my needs and help prevent me from slipping and scratching the air barrel ?

This tool doesnt appear to fit into the orifice slot, like a screwdriver would, it appears to get pushed down into the small hole at the center of the slot (per the schematic @ Scubatools) so if this is the case, how would this tool get the bite or traction to actually be able to turn the orifice ?

also saw this stubby screwdriver:

1/4" Stubby Screwdriver

Unless you screw the orifice way to far in, the exposed surface in the housing is not part of the orifice sealing surface. That stubby screwdriver should work just as well as any small, slotted screwdriver. You do need a fairly narrow blade as the slots on some Scubapro metal orifice can be quite narrow. Plus, everything should be fairly clean so it will take very little force to turn the screwdriver. With just a little care, you will be unlikely to slip and unlikely to scratch the surface if you do.

Some inline tool may have blades that are too wide (thick) to engage the narrow slotted orifice. Check before you buy.

 

[Couv]

Sorry I didn't see this thread until just now. The Usual Suspects are handling it well....thank you.

The adjustment is very simple-no special tools required. A thin flat (common) blade screwdriver is all you need. Just to reiterate what Awap said; when doing any orifice adjustments remember to depress the purge button. If you're getting too much flow with the diver adjustment knob all the way out just remove the hose, depress the purge and give the orifice a 1/4 clockwise turn. If that stops the freeflow, repeat but back it out until you get just a slight hiss.

 

[scubafanatic]

This tool makes it easy:

Shop Online

And this one is useful too:

Shop Online

It is fairly common to set these regs so that when the knob is full out they may very slightly leak. I personally prefer them not quite to that point but on the edge of doing so.

You might want to check and see if it is the diaphragms pressing on the levers once installed and tightened down. If so, this is a lever adjustment, please do not bend the levers to account for this.

N

Those tools look pretty neat, but I'm so inexperienced I'm not exactly sure what I'd do with them! I did see some tools that appear to allow orifice adjustment while the 2nd stage is pressurized, it appears (with the right tools) that the orifice can be adjusted 'on the fly' while the 2nd stage is pressurized, which would be a lot faster and easier than manually disconnecting/reconnecting the 2nd stage multiple times to adjust the orifice by hand. Am I understanding this tool correctly ? http://www.scubatools.com/p-540-dual-drive-inline-adjusting-tool.aspx

---------- Post added July 27th, 2014 at 10:25 PM ----------

Unless you screw the orifice way to far in, the exposed surface in the housing is not part of the orifice sealing surface. That stubby screwdriver should work just as well as any small, slotted screwdriver. You do need a fairly narrow blade as the slots on some Scubapro metal orifice can be quite narrow. Plus, everything should be fairly clean so it will take very little force to turn the screwdriver. With just a little care, you will be unlikely to slip and unlikely to scratch the surface if you do.

Some inline tool may have blades that are too wide (thick) to engage the narrow slotted orifice. Check before you buy.

I ordered the 'stubby screwdriver' this weekend, should arrive next week, my plan is to try the orifice adjustment procedure next weekend, thanks again!

---------- Post added July 27th, 2014 at 10:27 PM ----------

Sorry I didn't see this thread until just now. The Usual Suspects are handling it well....thank you.

The adjustment is very simple-no special tools required. A thin flat (common) blade screwdriver is all you need. Just to reiterate what Awap said; when doing any orifice adjustments remember to depress the purge button. If you're getting too much flow with the diver adjustment knob all the way out just remove the hose, depress the purge and give the orifice a 1/4 clockwise turn. If that stops the freeflow, repeat but back it out until you get just a slight hiss.

Thanks again, Robert! I'll try my hand at the adjustment process next weekend once the proper tool arrives this coming week, and we'll see how it goes.