Sherwood experts: are SRB 7300 and SRB 5600 both 'balanced' and both 'Maximus' 1st-stages ?

[scubafanatic]

I recently bought a used Sherwood 1st-stage only (SRB 7300 /yoke ), sold as a Sherwood Maximus 1st-stage, as well as a 2nd Sherwood full set of 1st and 2nd stage (SRB 5600 /DIN). Are both of these 1st-stages 'Maximus' 1st-stages ? Also, are these 1st-stages 'balanced' or not ?

Thanks in advance!

 

[JackD342]

SRB 5600 1st stage:
Flow-by piston with Moving Orifice Balancing, Dry Air Bleed, and Air Sensing Channel Boost

I don't find specific documentation for 7000 series, but my PDF that lists all of the other 5000 series has a file name saying it is for both 5000 and 7000. Description of 5000 series follows, and since that is balanced and preceded 7000 series, I am sure 7000 is also balanced.
Flow-by piston with Moving Orifice Balancing and Dry Air Bleed

Historically, Sherwood has not varied 1st stages much. The differentiation of models comes in the 2nd stages. Current line up is the SR2 first stage, and the 9000 series for all other models, including Genesis.

I don't know if you are familiar with the dry bleed on the older Sherwood 1st stages. By design there will be a little stream of champagne bubbles coming out of the 1st stage when in use. If there aren't any, something inside is plugged up and needs cleaning or replacing. (there is even a specific range of air volume released to measure when servicing)

 

[Bob DBF]

First stages are balanced. As for the names, Sherwood has consistently used the same names for their regs, so my Magnum from 1980 is different from the Magnum built today. I believe the Maximus came along more recently, but as the first and second change, the name remains.

Although I have used Sherwood regs for decades, I haven't had a Maximus, yet.


Bob

 

[scubafanatic]

SRB 5600 1st stage:
Flow-by piston with Moving Orifice Balancing, Dry Air Bleed, and Air Sensing Channel Boost

I don't find specific documentation for 7000 series, but my PDF that lists all of the other 5000 series has a file name saying it is for both 5000 and 7000. Description of 5000 series follows, and since that is balanced and preceded 7000 series, I am sure 7000 is also balanced.
Flow-by piston with Moving Orifice Balancing and Dry Air Bleed

Historically, Sherwood has not varied 1st stages much. The differentiation of models comes in the 2nd stages. Current line up is the SR2 first stage, and the 9000 series for all other models, including Genesis.

I don't know if you are familiar with the dry bleed on the older Sherwood 1st stages. By design there will be a little stream of champagne bubbles coming out of the 1st stage when in use. If there aren't any, something inside is plugged up and needs cleaning or replacing. (there is even a specific range of air volume released to measure when servicing)

Thanks for the confirmation of their 'balanced' 1st-stages, my main concern was greatly hoping to avoid an unbalanced 1sts-stage, so that's good news. I'm generally familiar with the dry bleed emitting a fine stream of bubbles under normal operation, hopefully the amount of air thus 'leaked out' is microscopic in the scheme of things...it IS minimal, yes ?

 

[scubafanatic]

First stages are balanced. As for the names, Sherwood has consistently used the same names for their regs, so my Magnum from 1980 is different from the Magnum built today. I believe the Maximus came along more recently, but as the first and second change, the name remains.

Although I have used Sherwood regs for decades, I haven't had a Maximus, yet.


Bob

Good to hear both 1st-stages are really balanced. I've not dove them yet as they need to be taken in for annual service and then pool testing. I'm new to Sherwood but building a couple of basic 'bullet-proof' sets as back ups for remote liveaboard style trips, figure the dry-bleed system will help reliability relative to the usual 'open' piston ambient chamber style 1st-stages.

 

[JackD342]

Thanks for the confirmation of their 'balanced' 1st-stages, my main concern was greatly hoping to avoid an unbalanced 1sts-stage, so that's good news. I'm generally familiar with the dry bleed emitting a fine stream of bubbles under normal operation, hopefully the amount of air thus 'leaked out' is microscopic in the scheme of things...it IS minimal, yes ?

Minimal is relative - eye of the beholder?
Older dry bleed version rate should be 13-27 cc/min, newer version should be 20-30 cc/min. Older models may have had that part upgraded, original parts are no longer available if it gets clogged and needs replacement.

 

[scubafanatic]

Minimal is relative - eye of the beholder?
Older dry bleed version rate should be 13-27 cc/min, newer version should be 20-30 cc/min. Older models may have had that part upgraded, original parts are no longer available if it gets clogged and needs replacement.

is it the case that older units can be upgraded or it's now too late to upgrade them if they weren't upgraded at some point in their past lives ?

 

[Bob DBF]

Good to hear both 1st-stages are really balanced. I've not dove them yet as they need to be taken in for annual service and then pool testing. I'm new to Sherwood but building a couple of basic 'bullet-proof' sets as back ups for remote liveaboard style trips, figure the dry-bleed system will help reliability relative to the usual 'open' piston ambient chamber style 1st-stages.

The seconds are drop dead simple to work on, so you might want to consider looking into that as well. Most issues I have had involve cleaning and adjusting the second.


Bob

 

[JackD342]

is it the case that older units can be upgraded or it's now too late to upgrade them if they weren't upgraded at some point in their past lives ?

I don't know if I would call it an upgrade, but the 2nd version is still available. I ordered a few within the past year. Old version was a single stainless steel part that resisted cleaning, new version uses a new part plus a replaceable filter at time of service, included in service kits. Unfortunately there is one other place where the flow can be restricted - the piston itself. I had to replace an old piston recently as the dry bleed output was just too low. It just wouldn't come clean enough to improve the flow.

 

[scubafanatic]

The seconds are drop dead simple to work on, so you might want to consider looking into that as well. Most issues I have had involve cleaning and adjusting the second.


Bob

Yes, I'll have 1st and 2nd stages serviced at the same time, simple design is what I was looking for for these back up reg sets, focus on being very reliable.