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    Subsea Pressure Housing Design – Wall Thickness for Stress & Buckling

    Ahh OK, makes more sense now. Still struggling with what the correct theoretical should be, though!
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    Subsea Pressure Housing Design – Wall Thickness for Stress & Buckling

    Oh, it will be two of these: https://www.macartney.com/what-we-offer/systems-and-products/connectors/subconn/subconn-micro-circular-series/subconn-micro-circular-2-3-4-5-6-and-8-contacts-and-g2-2-3-and-4-contacts/ The 'MCBH?F' variety.
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    Subsea Pressure Housing Design – Wall Thickness for Stress & Buckling

    Here is a Ø150mm x 590mm instrument: - http://www.valeport.co.uk/Portals/0/Docs/Datasheets/Valeport-MIDAS-CTD-plus.pdf Here is a Ø205mm x ~205mm instrument: - https://www.sonardyne.com/product/lodestar-gyrocompass-motion-sensor/ Obviously I have no idea of the wall sections, but can't imagine...
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    Subsea Pressure Housing Design – Wall Thickness for Stress & Buckling

    As a side note, there are companies that design subsea housings similar to what I'm aiming for: - https://prevco.com/shop - http://www.agoenvironmental.com/main-service/custom-pressure-cases I would like to understand the theoretical side of defining the wall thickness before I proceed to FEA...
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    Subsea Pressure Housing Design – Wall Thickness for Stress & Buckling

    Yes, I can see that since the process involves using their charts. Is my application definitely relevant for use with ASME Section VIII Div 1? I feel like it is, but it appears they've not written this spec for subsea applications specifically. I don't really have an objection tbh, you raise a...
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    Subsea Pressure Housing Design – Wall Thickness for Stress & Buckling

    There will be ports on the top and electrical connectors, therefore, not suitable for spherical design. Bracing is a possibility, but internal space is very limited and I'm not sure how much I could add here (if any) as well as not knowing how I could calculate stresses involved. As a side...
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    Subsea Pressure Housing Design – Wall Thickness for Stress & Buckling

    I’m designing a subsea sensor that will go to a max depth of 600 m (6 MPa/60 bar). In a simple model, it will be made of a pressure housing cylinder and two end caps, all grade 5 titanium. Some geometry is attached. I’m looking for advice on how to calculate the thickness of the...
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    Seal rotating parts/reduce friction (hand-tight thread)

    Could you explain this point further?
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    Seal rotating parts/reduce friction (hand-tight thread)

    That is a very good point with the deformation! I've no experience with PTFE coated o-rings - could be worth testing.
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    Seal rotating parts/reduce friction (hand-tight thread)

    I would like to have the entire assembly captive so that there's no chance of losing the parts (why there's a shoulder and a dowel pin either side of the threaded part). The centre piece must align with the block so that can't be threaded. You've sparked one idea: move the piston o-ring from...
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    Seal rotating parts/reduce friction (hand-tight thread)

    I am working on a design where I have a block which has a cap assembly fitted to it - see images attached. The cap assembly is constructed of: - Main body with two holes through (flowing water in and out) - Locking ring with a threaded outside, grooves for tightening by hand and two o-rings...
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    Seawater sample temperature control – heat exchanger design

    Any further input? Thanks in advance!
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    Seawater sample temperature control – heat exchanger design

    When I say block, I mean the entire metal section. The yellow section you've highlighted - is this distance something I should reduce in order to get faster temperature change? I want to hold the temperature constant and then run experiments on the sample at that temperature. When the temp is...
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    Seawater sample temperature control – heat exchanger design

    My apologies, my initial diagram was an early concept simplification - see attached for a better reason for having a glass tube. Essentially, all four bores are for optical purposes, with LEDs behind them. We had a previous product using the glass tube, but without the need for thermal control...
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    Seawater sample temperature control – heat exchanger design

    Sorry, the design was a simplification. The reason it is a tube is that at various angles in the block, there will be bores machines with light emitting into the glass tube, therefore, the block cannot be in a membrane or balloon. For this example, the seawater sample is only in the position...
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    Seawater sample temperature control – heat exchanger design

    I'll learn to quote, but can't find it on mobile! Yes, the water bath can be set to a range of temperatures, with the flow of water passing through the section on the right being at set temperature. The challenge is to get the sea water sample on the left to a desired temperature, and hold it...
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    Seawater sample temperature control – heat exchanger design

    "Since your range of temperature is both above and below ambient, you need a way to add heat or remove heat from the system. You did not describe that other than mentioning air cooling." The external water bath that is connected to the block will provide this?
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    Seawater sample temperature control – heat exchanger design

    "Does your system need to heat/cool a sample of sea water to a specified temperature from a specified temperature in a specified time? Or does it merely need to maintain the sample at a specified temperature?" Assume that the room is at ~20°C, it would need to be maintain the sample anywhere...
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    Seawater sample temperature control – heat exchanger design

    I’m designing a system where a sea water sample must have its temperature controlled between near its freezing point (-2°C) and +30°C to simulate sea temperatures. To control it, the sample will be in contact with a block, which will be controlled by an external circulating water bath. The image...
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    Load Shoulder Pressure Stress Calculations (Sketch Attached)

    Ahh OK, makes more sense now - I had assumed that because the part was sitting on a shoulder and subject to shear, you could use that as one of the load vectors, with compression the other. Is this 100% not the case then?
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    Load Shoulder Pressure Stress Calculations (Sketch Attached)

    Thanks - you seem well qualified! I do have good understanding of o-ring grooves and shear, the comment was more on what if the gland diameter was larger than the load shoulder bore diameter where the shear path would be at an angle, rather than straight through. What point would you include it...
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    Load Shoulder Pressure Stress Calculations (Sketch Attached)

    Wow, thanks! You seem to know your stuff so I'd like to pick your brains a bit more if that's OK. May I ask your background? It passes compression and shear with the shear length being at a 45° angle. I've had doubts about calculating shear length as being a straight back through the plug as I...
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    Load Shoulder Pressure Stress Calculations (Sketch Attached)

    Haha well I am the professional engineer, just lacking the experience... It is quite a common concept (seen quite often for pressure rated plugs/connectors etc.). I'm just curious as to the theory behind it and was hoping someone could help expand on my initial thoughts. Out of curiousity, what...
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    Load Shoulder Pressure Stress Calculations (Sketch Attached)

    Real world - it will be a component within the housing of an underwater sensor.
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    Load Shoulder Pressure Stress Calculations (Sketch Attached)

    I'm in the process of designing a part which must be submerged down to 2000m (200 bar/20 MPa/ 2900 psi). A sketch of the part has been attached. The outer housing will be titanium and the inner part aluminium. I've carried out the calcs for the outer part to withstand the external pressure, but...
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    Water Rocket-density,temp,drag

    I have a question about rockets This involves the d and temp of the water m | - a | - s | - s | - | - |-_________________ density So graph should look like ^^ and pV =(proportional to) d d=m/volume...
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