Just had a Sherwood Oais serviced. Reg is about 10 yr. old, never noticed it hard to breathe. Tech said intermediate press. was 125#, changed spring, added shim, and raised to 135#. Do these press. sound right ? Going on a 1 week trip off Kona in June, now not sure wether to buy new reg.? I dive mostly warm waters with force fins and have been known to tire in moderate currents. Always assumed short fins and large body mass to blame, now wondering about air flow. Any thoughts.
Intermediate Pressure ??
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Sounds right. Springs do get weak and I would be happy with 135# ip in that reg. Make sure the 2nd stage is retuned for that pressure or it might be a little touchy.
Randy43068
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sounds right to me. Most IPs it are set to 145 +- But yeah, the fix sounds reasonable to me.scubabear:
Specs for all Sherwood Regs are 140psi +/- 5psi so that sounds right on as long as he didn't put more than 3 shims in the first stage. That would be out of spec and the spring would be no good.
Randy43068
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Oceanseleven:
True enough. If more than three shims are needed, replace the spring.
An IP range of 125-145 is common but there is slight advantage in flow rates at higher IP's since you can move a greater volume of air through the reg in a given time interval at a higher IP. It's basically a linear function so you can estimate the increase in flow rate accordingly.
As indicated above, more than 3 shims total is a bad thing as it over compresses the spring and with a limited working range, the spring would be more likely to break. Since this is a failure that could shut off gas flow, it would be a bad thing to have happen.
As long as the second stage is tuned to the new IP, it will not be a problem. Those Sherwood second stages always breathed a lot better than they had any right to breathe and could often make an expensive seocnd stage look bad on the test bench so I see no need for a new regulator as long as it works for you.
As indicated above, more than 3 shims total is a bad thing as it over compresses the spring and with a limited working range, the spring would be more likely to break. Since this is a failure that could shut off gas flow, it would be a bad thing to have happen.
As long as the second stage is tuned to the new IP, it will not be a problem. Those Sherwood second stages always breathed a lot better than they had any right to breathe and could often make an expensive seocnd stage look bad on the test bench so I see no need for a new regulator as long as it works for you.
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