Dear all,

I found following problem in MDMT calculation in Pv-elite.

1.Pvelite does not evaluate MDMT for the tubesheet as per UCS-66

2.Pvelite does not evaluate MDMT for the materials listed in
UHA-23 as per UHA-51.

For austentic ferritic Duplex & super duplex steel Impact
testing can become applicable when limits of MDMT &
thickness exceed values given in UHA-51(d)(3).

In my opinion programe shall calculate this & shall give
warning where ever impact testing is required as per code.

Please share your views.

Hello Mr. Patel,

You will find in version 2013, that MDMT's for Stainless Steels will be reported and Tubesheet MDMT's will also be computed and reported.

Dear sir,

Thanks for your prompt reply.

I was little beat surprise when I came across this problem while evaluating MDMT for the one of the Shell & tube heat exchanger which is combination of duplex steel & carbon steel.Anyway it is good that you are going to incorporate this in your next issue.

What is meaning of the nominal material thickness in the clause
UHA-51(d)(3) is it same as governing thickness as defined in UCS-66?

For example which thickness need to be consider for evaluating MDMT for the STD. ASME B16.5/16.47 flanges?

Governing thickness is well defined term in UCS-66 based on which we check applicability impact testing of welded & non welded parts for carbon steel & low alloy steel.

But coming to high alloys specially duplex & super duplex steel code says 10 mm nominal material thickness irrespective of product form requires impact testing.

What is interpretation of the UHA-51(g)in relation with the UHA-51(d)(3)?

For other grades stainless steel like SS304 we can go up to -196°C with out impact testing.Than why code have stringent requirement of impact testing of duplex & super duplex steel?

Dear PVElite Team,

Currently we are using PVElite 2013 version, but still the MDMT values for Duplex Stainless Steel Tubesheets are not appearing in the output.

I am attaching herewith the original sample file in which I have modified the Design MDMT temperature and Tubesheet MOC as Duplex Stainless Steel SA182 F51 (UNS31803).

Kindly inform how MDMT for Tubesheet with MOC as Duplex Stainless Steel SA182 F51 (UNS31803) can be calculated.

Ashay sir,

This is due to issue with TUBESHEET MDMT calculation.

In your case if you input other component as duplex or any other stainless steel it will compute MDMT for component.which was not there in earlier versions.

But for tubesheet it is still a provlem it will not consider even for carbon steel.

Better to highlight such problem on pvelite ecustomer site

https://crmweb.intergraph.com/ecustomer_enu/start.swe?SWECmd=Start&SWEHo=crmweb.intergraph.com

Hope it helps.