[PSUBS-MAILIST] Steel Grade Query

Sun Apr 22 19:02:37 EDT 2018

Just to add to that - pressure vessel steels are so classed largely because of their fracture toughness, and not necessarily their strength. Heat treatment condition will play a role, but you probably want the low temperature rated steel if you're deviating from the approved alloys.

For reference:

Pressure Boundary Material Specifications

Plates (2010)

Plate materials of pressure boundaries, including attachments, are to comply with one of the following.

Steel (2008):
ABS Hull Grades E, EH32, EH36;
U.S. Navy Grades HY-80 and HY-100 per MILS-16216;
ASTM A516 Grades 55, 60, 65, 70;
ASTM A537 Class 1 and 2;
ASTM A517 Grades, A, B, E, F, J

Aluminum:
ASTM B 209 alloy 6061-T6;
ASTM B 928 alloys 5083, 5086, 5383, 5456 (see Section 5 of these Rules)

Titanium Alloys:
ASTM B265 Grade 5

Stainless Steel:
ASTM A240 Type 304 or 316

Acrylic Plastics (cast polymethyl methacrylate): ASME PVHO-1 and Section 7 of these Rules

Bolts, Extrusions, Forgings, and Shapes

Materials of bolts, extrusions, forgings, and shapes are to comply with a recognized standard at least of similar quality to the plate materials specified in 4/3.1 (e.g. MIL-S-23009 for HY-80 forgings, ASTM A350 LF2 or LF3 for forgings comparable to ASTM A516).

Materials Complying with Other Standards

Consideration will be given to the use of material complying with other recognized standards suitable for the service intended. Approval of the use of other materials will depend on satisfactory evaluation and approval of the specifications prior to construction.

Sean

-------- Original Message --------
On Apr 22, 2018, 13:48, Cliff Redus via Personal_Submersibles wrote:

> See table below of two important steel strength parameters, ultimate tensile strength and tensile yield strength.  At the very least, I would pick a steel that matches or exceeds the A516-70 spec.  If you are trying the get the boat ABS classed., will be a pain in the butt and expensive to use a non-ABS approved material.  If you are just trying to build a safe psub, pipe will work if the welding is done to code. Oil and gas industry uses a lot of API 5L X56 pipe so it is easy to get.
>
> I hesitated to respond this this query as there is a lot evolved to specifying steel.  Much more than can be covered in an email.
>
> Cliff
>
> Tensile Strength	Min Yield Strength
> Description	Common Use	psi	Mpa	psi	Mpa
> ASTM(A) 516-70	Plate for Boilers and Seperators	70,300	485	37,700	260
> A106 Gr C	Seamless Pipe	70,000	483	40000	276
> A333 Gr 6	Seamless Pipe	60,000	415	35,000	241
> API 5L X56	Seamless Pipe	71,100	490	56,600	390
>
> On Sun, Apr 22, 2018 at 2:35 PM, Jon Wallace via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>
>> You can change the parameters of the calculator to give you an accurate analysis of any steel.  I show 1276 feet max depth for A333Gr3.
>>
>> ---------------------------------------------------------------
>> From: James Frankland via Personal_Submersibles <personal_submersibles at psubs.org>
>> To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
>> Sent: Friday, April 20, 2018 9:25 AM
>> Subject: [PSUBS-MAILIST] Steel Grade Query
>>
>> Hi All.
>>
>> I am purchasing battery pods for my new sub.  I am attempting to get
>> 14"NB(355mm) x 98" (2500mm).  Standard weight (9.52mm)
>>
>> Psubs calculator give ABS depth of 1160 feet (353m) for A516gr70
>>
>> However, I don't seem to be able to get a516 in that for standard pipe.
>>
>> I keep getting offered A106grB or A333Gr3 or Gr6.
>>
>> 106 seems to be high temp, 333 low temp.
>>
>> Does anyone know about these and if they will be ok for battery pods.
>>
>> Its a lot cheaper to get std wt pipe than it is to get a516 custom rolled......
>>
>> Many thanks
>> james
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>>
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