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Thanks for the responses all, unfortunately we do not have maintenance requirements or data for existing equipment. This is a conceptual life-cycle cost estimate activity. Likely the best approach will be to just apply a uniform percentage of ~5% across all equipment types, similar to the rule...

Does anyone have a good reference with rules of thumb for estimating maintenance cost requirements of various types of process equipment compared to capital cost? I have a copy of Plant Design and Economics already but I am looking for something more granular based on the type of equipment. I...

I have seen 24" listed as the maximum size for A234 WPB (seamless) fittings; beyond that they are welded (WPB-W). Is there a standard that actually specifies this as as the breakpoint? Additionally, their pressure ratings should both be equivalent to seamless pipe if built to B16.9 (para 2.1)...

Thanks all, Not being familiar with ASTM A370, it was not clear to me that full size specimen =/= pipe body. That clears it up.

Thanks a bunch Steve, very helpful. I assume DWTT also produces energy values? Equations 1 and 2 in para 841.1.2 of B31.8 note the calculated CVN values as being "full size Charpy V-notch absorbed energy". That would indicate to me that these are in fact DWTT, not charpy tests. Annex G also...

I am reviewing a specification for a gas pipeline (material API 5L PSL2) with a minimum temperature of -50F. According to B31.8, this triggers Annex G of API 5L. I am really struggling to sort the actual requirements of CVN and/or DWT testing. - My understanding is that shear area is calculated...

Has an[u]yone had success with flexibility analyses using API 662 Table 1 for general service allowable nozzle loads on plate and frame exchangers? The allowable loads appear to be extremely low and necessitate two expansion joints per nozzle (in different axes) even for moderate operating...

The question is purely hypothetical. Most submersibles I've installed were for ambient or slightly elevated sumps for industrial waste or water runoff. I believe the motors were all oil-filled. I never understood how they get by without any kind of seal flush when horizontal pumps of similar...

Thanks for the response all. The submersibles I've seen do not require seal external seal flush. I guess a better question would have been: If submersible can operate satisfactorily in dirty service without flush water, why do other pumps require seal flushes or cooling, even for dual seal...

Most of the submersibles I've seen for industrial wastewater service use dual mechanical seals but it's not clear to me how they cool the seals or keep them clean. Wouldn't buildup occur in the primary seal as the process fluid evaporates across it? How is the secondary seal cooled?

Thanks HVAC-Novice, We have access to ashrae guidelines so that will be a good resource. Our area of competency is process equipment and piping specification and design. We run into HVAC systems generally for small buildings housing chemical feed pumps or electrical enclosures and have...

Good evening Steve, I’m wondering if anyone could point me in a direction for resources in sizing/specifying or reviewing packaged HVAC units for unoccupied spaces. Our office is increasingly responsible for sizing and/or procuring these units. Having enough competence to properly specify or...

Thanks for the responses all: SB = Small Bore, (< 2"). Everything above would be BW regardless as is standard. So we are *almost* exclusively discussing drains and instrument connections here. I say almost because this is just a FEED and it is conceivable additional process connections could be...

Does anyone have experience with using SW for SB pipe in wet CO2 service. I am finalizing specs for a CO2 Capture FEED and am trying to work out whether I should allow SW for SB pipe. Literature online indicates I may need a small corrosion allowance with 316/316LSS for this service (assuming a...

Thanks for the response bimr. I do disagree with your second statement. Tied expansion joints are often required to accommodate thermal pipe growth/contraction and prevent exceedances of allowable pump nozzle loads in properly designed systems. In fact, anchoring the pipe on either side of the...

I see that 9.3.10.4 of API 610 states that thrust restraints are required for expansion joints installed at pump discharge for VS1 and VS2 pumps but what about the suction side or other pump types? Are API 610 pump casings designed to transmit axial pressure thrust force to the support structure...

Thanks for the responses all, it is sounding like the approach we took is likely adequate. GT-EGR: I did confirm that the loss factors ASHRAE provided did not change with scale (i.e. loss factor for a 4"x4" bend was same for 8"x8", given the same velocity for the two cases). We did use CFD to...

Originally posted in general mechanical but did not receive any replies. This is not an HVAC application but maybe some folks here have some insight... We are in the final stages of a study and are currently estimating the resources it would take to bring the project from budgetary level of...

We are in the final stages of a study and are currently estimating the resources it would take to bring the project from budgetary level of definition to IFC. I am looking for some information on hydraulically modelling ductwork systems to size large fans (approx. 500,000 cfm @ 20” H2O). For...

Thanks for the responses. IFRs point is well made. I am still curious on how that threshold was selected (95F water is volatile??) if anyone has insight there.