Welcome to ScubaBoard, an online scuba diving forum community where you can join over 205,000 divers diving from around the world. If the topic is related to scuba diving, this is the place to find divers talking about it. To gain full access to ScubaBoard (and make this large box go away) you must register for a free account. As a registered member you will be able to:

  • Participate in over 500 dive topic forums and browse from over 5,500,000 posts.
  • Communicate privately with other divers from around the world.
  • Post your own photos or view from well over 100,000 user submitted images.
  • Gain access to our free classifieds marketplace to buy, sell and trade gear, travel and services.
  • Use the calendar to organize your events and enroll in other members' events.
  • Find a dive buddy or communicate directly with scuba equipment manufacturers.

All this and much more is available to you absolutely free when you register for an account, so sign up today!

NEW for 2014 Access SBlogbook for members. It allows you to directly upload data from your dive computer, validate your logs digitally, link your dives to photos, videos, dive centers (9,000 on file), fishes (14,000 on file) and much more.

If you have any problems with the registration process or your account login, please contact the ScubaBoard Support Team.
Results 1 to 5 of 5

Thread: Imperial to Metric tank capacity

 

  1. #1
    Registered


    Has not set a "status"
     

    elmagnoon's Avatar
    Join Date
    Jul 2005
    Location
    Vancouver
    Posts
    80

    Imperial to Metric tank capacity

    Is there a table of Imperial tanks and what their capacity is in metric?

    For example what's a Luxfur S80? Is it a 10 Litre?
    I have the following and would like their capacity in Metric


    Luxfur S080N
    Luxfur S040
    PST E130


    Thanks

  2. #2
    Registered


    Has not set a "status"
     

    dsteding's Avatar
    Join Date
    Feb 2006
    Location
    Seattle, downtown
    Posts
    1,073
    Dives
    200 - 499
    Metric capacity depends on working pressure. To get volume of gas you multiply the working pressure (in bar) by the volume of the tank (in liters). This gives you the total liters of gas in the tank. 1 cubic foot equals about 28 liters, so you then divide by 28 to get capacity in cubic feet.

    Not being terribly familiar with working pressure of metric tanks, I can't convert your volumes to metric.

    A quick search of the archives yielded this table that explains the liter/pressure difference (netdoc was using PSI here as a result of where the thread was going):

    Quote Originally Posted by netdoc

    10 litre = 0.353 cf
    2250psi tank... 54cf
    3000psi tank... 72 cf
    3300psi tank... 78 cf
    3500psi tank... 83 cf

    12 litre = 0.424 cf
    2250psi tank... 64 cf
    3000psi tank... 86 cf
    3300psi tank... 94 cf
    3500psi tank... 100cf


    15 litre = 0.530 cf
    2250psi tank... 80 cf
    3000psi tank... 107 cf
    3300psi tank... 18 cf
    3500psi tank... 125 cf


    20 litre = 0.706 cf
    2250psi tank... 109 cf
    3000psi tank... 143 cf
    3300psi tank... 157 cf
    3500psi tank... 167 cf

  3. #3
     


    Diving, diving, diving in Maui
     

    Charlie99's Avatar
    Join Date
    Aug 2001
    Location
    Silicon Valley, CA / New Bedford, MA / Kihei, Maui
    Dives
    500 - 999
    Photos
    35
    http://www.luxfercylinders.com/produ...s_metric.shtml give specs for Luxfer cylinders in metric. The most common AL80 is the S080, which is 2kg positve buoyancy when empty. It's fill pressure is 3000psi or 207 bar. Water volume is 11.1 liter.

    I don't have a metric table for the PST cylinders handy, but

    130cu ft at 3442psi is 130cf * 28.4 l/cf = 3692l at 232 bar = 15.9 liter cylinder.
    Last edited by Charlie99; May 6th, 2007 at 04:09 PM.

  4. #4
    Registered


    Has not set a "status"
     

    elmagnoon's Avatar
    Join Date
    Jul 2005
    Location
    Vancouver
    Posts
    80
    Thanks for the replies. They're very very helpfull though I'm still digesting the numbers.

    Qustion for Charlie99:

    If an E130 holds 130 cubic feet of comressed air and a S080 holds 77.4 cubic feet. The E130 holds approximately 68% more compresed air than the S080.

    Would I be able to apply the same comparsion in metric and say that an S080 with 11.1Litres @ 207 bar= 2297.7 Litres of air, then an E130 @ 232 bars will hold 68% more = 3860 Litres of air. Which brings the E130 closer to being a 17 litre tank.

    Does that make any sense?

  5. #5
     


    Diving, diving, diving in Maui
     

    Charlie99's Avatar
    Join Date
    Aug 2001
    Location
    Silicon Valley, CA / New Bedford, MA / Kihei, Maui
    Dives
    500 - 999
    Photos
    35
    Per this PST spec sheet it is a 16.6 liter tank. http://www.pstscuba.com/PST%20Scuba%...on%20Sheet.pdf (pdf)

    ========================
    There are some weird things about converting back and forth ---

    3442psi converts to 237bar if you use 14.5psi per bar. I think that discrepancy is that EC rates fill pressure at a lower temp than does the USA.

    Particularly at higher pressures, each additonal atm doesn't add additional free gas equal to the water volume (Van Der Wals effect. Departure from ideal gas).

    Rather than bar * size to get free gas, technically is should be atm * size. Another 1.325% error.

    It's really 28.3 liters per cubic feet, not the 28.4 that I used (12 cubed * 2.54 cubed / 1000).

    Put all of this together and it adds up. The S080 actual free volume of 77.4cu ft is 2192 liters, not the 2297.7 you came up with by multiplying 11.1l * 207bar.

    Of course, this all is in the noise compared to the variations in RMV.

Similar Threads

  1. SAC : metric to imperial
    By verybaddiver in forum Basic Scuba Discussions
    Replies: 2
    Last Post: February 18th, 2007, 11:39 PM
  2. VT3 metric to imperial?
    By tomhorton1987 in forum Oceanic
    Replies: 8
    Last Post: February 9th, 2007, 10:43 AM
  3. suunto eon metric vs imperial
    By storm1fishing in forum Computers, Gauges, Watches and Analyzers
    Replies: 6
    Last Post: April 19th, 2005, 10:30 PM
  4. Reprogramming from metric to imperial
    By northcoastdiver in forum Computers, Gauges, Watches and Analyzers
    Replies: 0
    Last Post: August 20th, 2003, 05:29 PM
  5. Imperial -vs- metric
    By Dectek in forum Non-Diving Related Stuff
    Replies: 2
    Last Post: January 2nd, 2003, 01:49 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •