[PSUBS-MAILIST] Snorkel

Wed Jan 14 18:57:33 EST 2015

Is it always possible to manually actuate the valve if you have a negative differential pressure?  I always presumed that a ball or needle valve would be necessary to equalize pressure on either side of a hatch before opening, because such a valve accommodates pressure differences in either direction.  With the overpressure valve, in such a situation you need to overcome this difference in addition to the spring preload. That, or I guess you could just bleed some air or oxygen into the cabin.

Sean

On January 14, 2015 12:36:36 PM MST, Alan James via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>Brian,I seem to remember you can manually operate Emile'soverpressure
>valve; and it is operating procedure to pressit to relieve the
>remaining pressure before opening the hatch.If you are looking for an
>off the shelf solution, make sureyou can do that.Alan
>From: Brian Cox via Personal_Submersibles
><personal_submersibles at psubs.org>
>To: Personal Submersibles General Discussion
><personal_submersibles at psubs.org> 
> Sent: Thursday, January 15, 2015 6:11 AM
> Subject: Re: [PSUBS-MAILIST] Snorkel
>   
>I don't see where they list the pressure limit on it. Brian
>
>--- personal_submersibles at psubs.org wrote:
>
>From: James Frankland via Personal_Submersibles
><personal_submersibles at psubs.org>
>To: Personal Submersibles General Discussion
><personal_submersibles at psubs.org>
>Subject: Re: [PSUBS-MAILIST] Snorkel
>Date: Wed, 14 Jan 2015 16:31:56 +0000
>
>what about something like this?  I only just googled it so would need
>research.  Don't quote me on
>it! http://www.haitima.com.tw/valve/check-valve/check-valve-2026.htm
>On 14 January 2015 at 15:55, Brian Cox via Personal_Submersibles
><personal_submersibles at psubs.org> wrote:
>
>
>
>Is there an off the shelf over pressure valve that I can get? Brian
>
>--- personal_submersibles at psubs.org wrote:
>
>From: James Frankland via Personal_Submersibles
><personal_submersibles at psubs.org>
>To: Personal Submersibles General Discussion
><personal_submersibles at psubs.org>
>Subject: Re: [PSUBS-MAILIST] Snorkel
>Date: Wed, 14 Jan 2015 13:58:24 +0000
>
>Yes, my OP valve does not have enough holes.  I have a job over the
>winter to add more or drill existing holes bigger.  
>On 14 January 2015 at 13:04, Emile van Essen via Personal_Submersibles
><personal_submersibles at psubs.org> wrote:
>
>Mark, All.
>
>Mind the area is big enough. The valve in the attachment is designed
>for a
>3000 Kg sub. But even then it is to small if you surface too quick in
>case
>of massive overpressure.
>Cracking pressure: 25-75 mBar.
>
>
>Best regards, Emile
>
>-----Oorspronkelijk bericht-----
>Van: Personal_Submersibles
>[mailto:personal_submersibles-bounces at psubs.org]
>Namens Mark via Personal_Submersibles
>Verzonden: dinsdag 13 januari 2015 13:12
>Aan: Personal Submersibles General Discussion
>Onderwerp: Re: [PSUBS-MAILIST] Snorkel
>
>Since we are discussing over-pressure valves, can you recommend a make
>and
>model, or describe its specifications?
>
>Regards,
>
>Mark...
>
>Sent from iPhone.
>
>> On Jan 12, 2015, at 7:06 PM, Pete Niedermayr via
>Personal_Submersibles
><personal_submersibles at psubs.org> wrote:
>>
>> Scott, I see you have an overpressure valve in place of the snorkel .
>Whats that on the other side ?
>>
>> Pete ?
>> --------------------------------------------
>> On Mon, 1/12/15, via Personal_Submersibles
><personal_submersibles at psubs.org> wrote:
>>
>> Subject: Re: [PSUBS-MAILIST] Snorkel
>> To: "Personal Submersibles General Discussion"
><personal_submersibles at psubs.org>
>> Date: Monday, January 12, 2015, 5:09 PM
>>
>> I
>> would recommend a cabin overpressure valve instead. It is a
>> mushroom valve. You can see pics on my sub page. Alec
>> did the same thing.
>>
>> Thanks,
>> Scott Waters
>>
>>
>> -------- Original
>> Message --------
>> Subject: [PSUBS-MAILIST] Snorkel
>> From: Pete Niedermayr via Personal_Submersibles
>> <personal_submersibles at psubs.org>
>> Date: Mon, January 12, 2015 3:58 pm
>> To: personal_submersibles at psubs.org
>>
>> I have a set of K 350 plans that I'm using as a
>> reference for my own design. I'm using the conning tower
>> plans pretty much as per. The question I do have is. Snorkel
>> or no snorkel ? On the one hand I can see how it would be
>> useful have. On the other hand no other design seems to have
>> one. What are your opinions? Snorkel or no snorkel?
>>
>> Pete
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