Scubapro D-Series Reg questions

[Timothy Moran]

I have 13 SP 2^nd stages; 1 ea Pilot converted to AIR 1; 4 ea AIR 1’s; 1 ea R109; 3 ea G250’s; 2 ea D300’s; and 2 ea D400’s. I have read and studied Vance Harlow’s book, “SCUBA Regulator Maintenance and Repair.” I need some advice on the D-series regs. Part number references below come from SP Schematic 11-114-000 Rev L.
1. The spring (p/n 01020155) pressing against the poppet is of a different free length in each reg. The D400’s have .740 inch and .617 inch lengths, and the D300’s have .695 inch and .625 inch lengths. This seems to be a rather large variation. It affects the tuning adjustments. As these are older regs, I don’t know their service history. Possibly someone installed the wrong length spring(s), or the springs got stretched.
Question: What is the correct length for this spring?
2. The dive/predive switch spring (p/n 11011118) appears to be long enough to allow the lever (p/n 11014103) to be installed from either side of the orifice slot. One of the D300’s I took apart and cleaned up/overhauled has the lever installed from the right side (reg oriented supply tube up and looking at the diaphragm seat.)
Question: Is the lever installed from the right side correct (and does it matter which side the lever is installed from?)
3. Does soaking in warm water help in removing the rubber cover? Link below also mentions using soapy water.

What I do know about my 4 D-series regs:
4. No Bulletin 268 mod incorporated – all have the one-piece metal orifice and single-mill-cut lever.
5. There are no spring pads (p/n 11015306) in these regs. (Could be these are Bulletin 268 parts?)
6. 2 regs have the older metal stem poppets with replaceable seats, 2 are the newer type one-piece plastic poppets.
7. Cracking pressure should be somewhere around 1.0 to 1.5 inches of water.

The link below has some of the best info I have found on DIY overhaul of the SP D-series regs:
http://www.scubaboard.com/forums/repairing-your-own-gear/424439-d400-raising-w.html
Any other help or recommendations would be greatly appreciated.

In my opinion, Scubaboard and its members are one of the great resources in the diving community.

TJ Moran

 

[halocline]

If no one beats me to it, I'll try to take one of my D300s apart this evening to help you out. I do know that the lever on the D300 is oriented on the other side from the D400, and cannot be reversed. There's a notch on the lever that sits against the set screw; this notch is cut at a slight angle so that the lever will extend down either pointing slightly away from the diaphragm or towards it. You want it pointing away. I realize this isn't much of an explanation but as I said I'll try to get to one of mine this evening.

I don't have any spring pads on my D300s. I also don't have a micrometer so I can't help you with the actual spring length. I've probably owned around 10 D300s and have never had a problem with those springs, although some of my regs have been easier to tune (and stable at best tuning) than others, and I suspect the spring condition is responsible for that.

There's a good D400 repair manual I can send you by email if you would like.

I just pull the rubber covers off, sometimes using a plastic or wooden implement to help get one side over the diaphragm cage. It's a bit scary because you really think you're going to tear it, but I've never had a problem.

Be very very careful removing the diaphragms from the converted pilot and air1. It's really easy to tear those, guess how I know that?

 

[Timothy Moran]

Halocline, thanks for the good info on the D-series regs. You have captured and explained the essence of my question about the lever orientation. I understand the D300 wants the lever orientated away from the diaphragm, and the D400 is opposite, or towards the diaphragm. AIR 1's have an adjustable threaded rod and back-up disk in place of the slotted linkage lever on the D-series.

I have a copy of the SP manual for the AIR 1 (around 8 pages.) If you could e-mail me a copy of the manual for the D-series, I would greatly appreciate it.
My e-mail address is: TJ_Moran@Roadrunner.com

Thanks again for your wealth of knowledge and support,
TJ Moran

 

[redacted]

I suspect spring force of the installed spring is more important than spring length of the uninstalled spring. While I am a bit surprised at such differences, if they work OK I'd write it off as some sloppy production parameters.

 

[Timothy Moran]

More questions on D-Series regs

Further to my question about the different spring lengths on my D-Series Regulators:
1. I made a U-tube manometer and measured inhalation and exhalation numbers. As AWAP suggested, spring free length doesn’t seem to affect cracking numbers, as long as spring adjustment can take care of the issue. However on some regs with the adjustments as loose as possible, the poppet/orifice would not flow. I tend to believe this could negatively affect tuning for optimum performance.

2. I checked the levers and found I have 2 different configurations in my 5 D-series regs. 4 levers are made with .100 inch dia wire, and 1 is made with .118 dia wire. The D-400 No S/N with the .118 dia lever has the lever installed with the open end facing away from the aspirator notch; the other 4 regs have the .100 dia levers installed with the open end facing towards the aspirator notch both per SP D-series assembly instructions. The .100 dia wire levers also have a flat formed on the end attaching to the diaphragm linkage. The .118 dia lever does not have this flat. The .100 dia levers have the milled fulcrum slot set at about positive 4.4 degrees from vertical. The .118 dia lever has the milled fulcrum slot set at about negative 6.75 degrees. The difference in the angles is accounted for by the different side of the aspirator the lever is installed on.

3. Another different feature I noticed is the diaphragm covers beneath the rubber cover has 2 configurations: one I call short and one I call tall. The regs S/N’s 17090171 and D-400 No S/N have the tall covers, and the other 3 have the short covers. In staring at the covers, it appears the taller cover would tend to shield the exhaust valve somewhat if turbulent water were flowing across (or through) the exhaust ports and affecting the performance of the exhaust valve. I’m only guessing? Anyone have any thoughts on this one?

4. I think based on what I’ve found:
a. Some of the differences may be due to SP’s production changes, improvements, etc.
b. As I don’t know any of the history on any of these regs, they could have had different model parts installed/interchanged. I think D-400 S/N 17786020 is not correctly identified.
c. Serial number research to ID the original builds would be nice, but we all know with SP that is hopeless as these regs are no longer supported.

I’ve attached a .pdf file with what I’ve done so far.
To any of you SP reg-heads out there who can give any enlightenment to the above issues, I would greatly appreciate it.

Thanks to those of you have helped me get this far with understanding/working-on/tuning these great breathing regs.
TJ MoranView attachment D300-D400 Scubaboard rev A.pdf

 

[Timothy Moran]

Further to my questions/issues with my D-Series Regulators:
1. Two of my D300 regs have cracked plastic caps due to overtightening sometime in their life. The plastic cap P/N is 11-011-126. I have checked and I can also make the metal cap, PN 11-126-104, from an AIR 1 work on the D300’s with some light machining. Also the Retainer Aspirator, P/N 126-148, removed from a converted (to AIR 1) Pilot will fit. If anyone out there has any of these items they are willing to part with, please let me know.

Once again, thanks to all Scubaboard members who have helped me with these regs.
TJ Moran
E-mail: TJ_Moran@Roadrunner.com

 

[Ms.Miya5]

Is that D-series manual still available? I am working on a D300 and D350, and possibly a D400. all LDS's state the D-series is still proprietary Reg's and cant touch them.
ms.miya5@gmail.com
Thanks

 

[jrltenn]

I'll second that request. I haven't had any luck finding a manual for the d series. Maybe someone could post it here.

 

[wwunder]

Not sure where I originally found this or if its allowed to be posted here...

 

[jrltenn]

Many thanks wwunder! That's what I was looking for.