Bellevue Washers Source for Sherwood Magnum?

[JackD342]

Look at the schematic you attached for Magnum II - it has your answers.

The SRB3300 is configured slightly differently for the Blizzard than for any of the other 2nd stages it was used with. It uses only 4 Belleville washers instead of 5, and that part number is slightly different. It also uses a different moving orifice and 3 other different or additional parts. No idea how performance will be affected if you start mixing and matching configurations and parts. All of this is noted and explained in that diagram.

If your reg was in my shop and I had any doubts, I would be calling Sherwood with questions.

 

[JamesBon92007]

For whatever it's worth, I took one apart and took a picture.

The first time I worked on a SRB3300 and discovered it had only four washers it was very noticeable because the schematic showed five, however my schematic is not for the exact model but for a later model. Since the others also have four I was not too concerned, especially when I found the other diagram which showed four for some models. The Brut doesn't have any disc springs and it works This particular photo is from a first stage that has four LP ports. At least one of my first stages has only three LP ports but otherwise appears to be the same inside. I'm pretty sure it also has four disc springs but that is based upon my memory. The one with only three LP ports also has a hex screw holding the purge valve in place and the ones with four LP ports have a purge valve that just pops into place, much like most exhaust valves on second stages. I'm thinking that the one with three LP ports was the earliest model (purchased in 1983) but I cannot confirm that. I'm also not quite certain of the model number as some are referred to as SRB3305.

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[JackD342]

For whatever it's worth, I took one apart and took a picture.

The first time I worked on a SRB3300 and discovered it had only four washers it was very noticeable because the schematic showed five, however my schematic is not for the exact model but for a later model. Since the others also have four I was not too concerned, especially when I found the other diagram which showed four for some models. The Brut doesn't have any disc springs and it works This particular photo is from a first stage that has four LP ports. At least one of my first stages has only three LP ports but otherwise appears to be the same inside. I'm pretty sure it also has four disc springs but that is based upon my memory. The one with only three LP ports also has a hex screw holding the purge valve in place and the ones with four LP ports have a purge valve that just pops into place, much like most exhaust valves on second stages. I'm thinking that the one with three LP ports was the earliest model (purchased in 1983) but I cannot confirm that. I'm also not quite certain of the model number as some are referred to as SRB3305.

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You have lost me. I thought you knew for sure which model you were working on.
Bottom line is that there are multiple configurations that use 4 washers instead of 5, and that they don't all have the same part number. If you are working on one that has 4 washers, it is far more likely that you are working from the wrong schematic than that you are missing a part.

 

[Couv]

You have lost me.

Yep, @JamesBon92007 time for a summary please.
Which models use 4 washers?
5 washers?
What are the part numbers?
Are there aftermarket parts available; e.g. something from McMaster-Carr?

Thanks,

Couv

 

[JamesBon92007]

The early Sherwood 3300 first stages have four The schexatic I have shows five but it's for a later version Other than that the diagrax is usable for reference I don't think I'x xissing a part--on three regulators they each have four springs and not five

This keyboard is not working so guess which letter I replaced with "x" and you'll know which one I'x on Cozuxel right now so I can't look anything up but will later when I get back to California Xy period and coxxa don't work either

 

[Couv]

Thanks Jaxes, Look forward to your update. Have fun.

 

[JamesBon92007]

Thanks Jaxes, Look forward to your update. Have fun.

LOL

 

[JackD342]

The early Sherwood 3300 first stages have four The schexatic I have shows five but it's for a later version Other than that the diagrax is usable for reference I don't think I'x xissing a part--on three regulators they each have four springs and not five

This keyboard is not working so guess which letter I replaced with "x" and you'll know which one I'x on Cozuxel right now so I can't look anything up but will later when I get back to California Xy period and coxxa don't work either

I don't think that is exactly correct yet. First, why are you calling this (or is there more than one?) 1st stage a Magnum and/or a 3300? Is there a model number printed on the side of the 1st stage? Is there a Magnum 2nd stage attached? Or are you just matching what you see to a schematic that you have found?

My research says:
I don't know if they were marking the 1st stages at the time they way did with later generations, but the 3305 1st stage was sold with a Magnum II 2nd stage and the set was SRB3300. With an Oasis 2nd stage the set was SRB3400. With an Oasis+ 2nd stage the set was SRB3500. And finally, with a Blizzard 3205 1st stage and Blizzard 2nd stage the set was SRB3200. Aside from the possible markings on the exterior, ALL four are EXACTLY the same 1st stage... except that the Blizzard had some different internals, including 4 spring washers rather than 5. I do not believe the 4 spring washers you found are an "earlier" Magnum II; as previously explained it is FAR more likely that you have a misidentified Blizzard. Or someone did a (complete? partial?) modification of an Oasis or Magnum to a Blizzard version. You may be able to tell the difference with the moving orifice, which is one of the other Blizzard specific variations. All those details are listed at the bottom of the schematic you already posted.

There was also a slightly different 3800 series (Down Stream Sensing system) 1st stage with the Ultima 2nd stage, and later runs of the Oasis +.
And other similar but not the same variations for 3600, 3700, 3900.

So to repeat my question, how have you identified this as a Magnum 3300?

 

[JackD342]

Okay, I just spent far too much time trying to list all the known Sherwood regulators over time. (but not octos, I'll come back to that another day) And I may as well post it here.

I have tried to list these in an approximate chronological order, but don't take my sorting as bible. My first priority was to group items together that use the exact same 1st stage. Sometimes I just assumed what was older based on the look of the service manual. It does NOT seem like model numbers are a definitive means to sort old to new, just an approximation. Where I could find actual model numbers for separate 1st and 2nd stages I provided them, otherwise I left them blank.

 

[JamesBon92007]

So to repeat my question, how have you identified this as a Magnum 3300?

That's what it says on the boxes that two of them came in and on the brochure that came in the box Two were bought new in 1983 and one was purchased used more recently I thought I had the 3300 service manual somewhere but couldn't find it recently for verification I'm on a dive trip until next month but I'll try to find all the info when I get home (my period key quit working) The maximus regulator that I was repairing originally had five Bellevilles and I repaired it with five and it works very nicely now but it's probably not something I'd actually go diving with