Hydraulic Fitting - Max Temperature

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Discussion Overview

The discussion revolves around the suitability of a hydraulic fitting for high-temperature applications, specifically whether a #12 BPP Female Coupling can withstand 800°F in a diesel engine exhaust system. Participants explore standards, material specifications, and potential fitting alternatives, with a focus on hydraulic piping standards and welding methods.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant questions the temperature tolerance of the #12 BPP fitting and seeks confirmation on its suitability for a diesel engine exhaust application.
  • Another participant suggests referring to ASME B31.3 for stress allowables at high temperatures and emphasizes the importance of considering bending moments in addition to pressure loads.
  • A participant expresses familiarity with MS and Parker fittings and requests an equivalent part number for better identification.
  • Another participant mentions the need for ASTM material specifications to determine stress allowables and suggests calculations for wall thickness or derating the component based on temperature and pressure ratings.
  • A separate query about hydraulic piping standards in Brazil raises concerns about using sleeves for joining pipes and the need for compliance with ASME standards.
  • A participant references specific paragraphs in ASME B31.3 regarding listed and unlisted fittings, highlighting the responsibility of the system owner to ensure compliance when using unlisted fittings.

Areas of Agreement / Disagreement

Participants express varying levels of familiarity with the specific fitting in question and the applicable standards. There is no consensus on the suitability of the #12 BPP fitting for the specified temperature, and multiple approaches to addressing the hydraulic fitting standards are discussed without resolution.

Contextual Notes

Participants note the importance of material specifications and the potential implications of using unlisted fittings, indicating that further calculations or standards references may be necessary to ensure compliance and safety.

Ronnin
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Customer of mine is wanting me to confirm that a hydraulic fitting I am selling him will withstand 800F. The fitting is a standard issue hydraulic fitting (#12 BPP Female Coupling) that will be welded to 6" SHD 80 pipe. The pipe is on the exhaust side of a diesel engine onboard a cruise ship. No real pressure to speak of because it's venting to atmosphere. I haven't had much luck finding a clear cut answer. Since I'm in bearings and PT now I don't have the same contacts I use to. Any ideas?
 
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I've never heard of a #12 BPP, but if this is a US application, the stress allowables for the material from ASME B31.3 at the given temperature apply unless there's a specification for the fitting such as an MSS spec. Note that pressure on a vent header is just one consideration. Bending moments imposed by the venting of fluid are another consideration, so simply saying there's no pressure load is misleading.

In Europe, there's an equivalent pressure code, but I'm not familiar with it.

If this is US, provide the ASTM material spec, grade and temper and I can see what the code gives for stress allowable.

Once you have that, you can either do calculations on the wall thickness (you'll need to post a drawing) or you can derate the component by using the stress allowable at temperature divided by stress allowable at ambient times the pressure rating at ambient (assuming you have a pressure rating at ambient).
 
FredGarvin said:
I am use to MS and Parker fittings. Is there an equivalent Parker part number you can throw out? By your description, it sounds like a pipe coupling similar to this:

http://www.discounthydraulichose.com/v/vspfiles/photos/5000-2T.jpg

Yep, 3/4 Brittish Pipe E/E. Will have to look up the Parker number, I don't remember any of the nomenclature for anything other than pipe, JIC, or OFS.
 
Q_Goest said:
I've never heard of a #12 BPP, but if this is a US application, the stress allowables for the material from ASME B31.3 at the given temperature apply unless there's a specification for the fitting such as an MSS spec. Note that pressure on a vent header is just one consideration. Bending moments imposed by the venting of fluid are another consideration, so simply saying there's no pressure load is misleading.

In Europe, there's an equivalent pressure code, but I'm not familiar with it.

If this is US, provide the ASTM material spec, grade and temper and I can see what the code gives for stress allowable.

Once you have that, you can either do calculations on the wall thickness (you'll need to post a drawing) or you can derate the component by using the stress allowable at temperature divided by stress allowable at ambient times the pressure rating at ambient (assuming you have a pressure rating at ambient).

I'll try to find an available drawing and post, but most of the informaiton out of the cats won't have anything besides the configuration of the adapter. I knew I should of just told this customer I don't handle anything fluid power anymore. Me and my award winning customer service.:-p
 
gentleman,
I am having problems to locate the standards for hydraulic piping up to 300 bars accoording to ASME B31.3.
Here on sight in Brazil the main contractor wants to use sleeves to join the pipes together and weld them as a filled weld.
can they do that and where do i find these standards in ASME.
Thanks for your help.
 
See ASME B31.3, para. 306.1.

"Listed Fittings" per para. 306.1.1 cover standard fittings (ex: elbows and tees) such as socket weld fittings per ASME B16.11 and buttweld fittings per ASME B16.9. These would be most like the fittings you're describing but since they meet the ASME standard, you can be sure of the pressure rating without doing calculations.

"Unlisted Fittings" per para. 306.1.2 would cover the fittings you describe that consist of a sleeve with fillet welds. If you use an unlisted fitting as you're proposing, it is incumbant on the system owner to prove the fitting meets the piping code.

Generally, I'd suggest simply butt welding pipe together as this is considered the strongest method of joining pipe.

Don't forget about radiograph and leak testing of your system.