sherwood regs

[diverrick]

I recently got a used regulator set from someone, and I took it to the LDS to have it checked out.
When we put air to the set, both regs leaked a slight bit of air out of the second stages, a slight HISSSSS.
I mentioned this to another friend of mine who has Sherwoods, and they told me that they had been told by another shop that it was normal for Sherwod regs to leak air , as that keeps the reg from getting water in it. I am wondering if this thing about Sherwood purposfully leaking is correct. Any body know?

 

[CincyBengalsFan]

Absolutely NOT. The 2nd stages should not free flow or bleed of any amount of air. The first stage will bleed off air throughout the dive. It's a unique and top performace type of 1st stage.

The regulator just needs to be taken to a reputable Sherwood tech.

They can have it ready in a day or two for you.

Sherwood was making valves 100 yrs. ago for factory equipment and locomotives, etc. etc....

They know what they are doing better than any other regulator manufacturer in my humble opinion.

 

[ScubaRon]

CitiBengals is absolutely right. The 1st stage bleed that Sherwood is known for keeps water out of the regulator chamber making it possible to dive them in polluted and/or very cold water. However it is a very minimal bleed - just an occasional air bubble. I think I read somewhere that it equates to about 2 breaths per tank.
ScubaRon

 

[shrwdtech]

The amount of air that bleeds off of the Sherwood 1st stage is appoximately a measuring cup full.

If you are getting 2 breaths of air loss, it's bleeding off a bit much. The good side would be that it's still keeping the water and contaminates out of your reg.

The most common reasons for your leakage of air from the 2nd stage are a worn HP seat, worn LP seat, or a soft spring in the 2nd stage. Any of these are easily fixed by an authorized Sherwood Repair Tech during an annual service.

Take your regs in, get them serviced and ENJOY!!!

 

[DORSETBOY]

Sounds like my sherwood regs could do with a service, they're leaking a 'bit' more than a cupfull of air from 1st stage which I assumed was normal!

 

[diverrick]

When you say a cupfull of air is normal... In what time period? a minute, or the whole tank full? It makes a difference. Also, how do you determine a "cupfull" ? I assume your talking about ambient air, not compressed. I'm not trying to be funny here, just curious. So from what i am understanding, a slight hissing is normal, Right? BTW, They are out for a check up right now. Don't want to take any chances you know.

 

[shrwdtech]

It's an average, but from full to empty using a standard aluminum 80cu ft. cylinder for the length of an average dive at average depths.

I know that sounds vague, but that's how it's explained. *laughing*

You will lose approximately a measuring cup full of air. Like the measuring cup in the kitchen.

 

[SubMariner]

I have to agree that using "a cupful" as an measurement of air consumption is very confusing.

Regardless, the amount of air Sherwood bleeds out of the 1st stage is negligible. You won't notice it on your air consumption at all. In fact, many people dont even realize the reg has a positive bleed from the first stage at all, it's that little.

I've had a Sherwood Blizzard since 1991 and never noticed any measurable drain on my air supply.

Just my $0.02's worth,

 

[dmdoug]

Sherwood's first stage dry air bleed is said to work as long as there is in excess of 500psi in the tank.

The actual amount of air that is supposed to bleed off is approximately 10ml per minute.

SubMariner is correct in saying that it will not affect your SAC rate with the dry air bleed.

I was always told "little bubbles means little troubles," however if there is a true hiss from the 1st or 2nd stage it may need something as little as a high pressure seat or an O ring.

Dive safe,

 

[Drew Sailbum]

states that the proper bleed rate is 13-27ml per minute. That's 780-1620ml/hr.

According to the Respiratory Physiology Dictionary at John's Hopkins School of Medicine, the "Tidal Volume ... is the volume of a normal inspiration (or expiration) during quiet breathing, and averages about 500 ml."

Somewhere arounf 1-3 quiet breaths in an hour. Not much air.