17-4PH Valve Stem material 1

[Isha90]

Which is the best A564 Type 630 condition for Valve stem material,can we us condition H1075,what is the Max. & Min temp. of various conditions of Type 630,is there any restriction in using Type 630 as Stem material, appreciate your reply, Thank you

 

[metengr]

More information is needed to provide any meaningful results. First, what was the original valve stem material you are replacing? This sounds like a replacement consideration.

Second, what type of valve and service conditions?

 

[Isha90]

XM-19[Nitronic50]was my choice,valve type API602 Globe, line medium Gas, Design temp 275°C

 

[metengr]

I would stay with the Nitronic 50 stem material versus the 17-4 PH because of galling resistance needed for the globe valve stem/seat.

 

[Isha90]

Thank you, Choice of using A479 TY.XM-19 in Globe was due to Trim16 requirement, Tp.316 MAST was lesser than Actuator torque.
H1075 had higher yield strength & cheap$ when compared to XM-19.

17-4 PH Stem are being used in Ball valves, so could clarify "Which is the best A564 Type 630 condition for Valve stem material,can we us condition H1075,what is the Max. & Min temp. of various conditions of Type 630,is there any restriction in using Type 630 as Stem material," appreciate your reply, Thank you

 

[metengr]

Ball valves function differently in comparison to globe valves. With that said, the choice of a stem material depends on several factors, - fluid, service temperature and galling resistance, as I mentioned previously.

I don't see a prohibition for using 17-4PH other than the higher strength heat treatment could lead to increased susceptibility to environmentally assisted cracking. Also, the higher strength will result in less ductility which could effect performance as a valve stem. The maximum service use temperature I have seen for this material is 600 deg F.

 

[Isha90]

Thank you, Could you share more information Valve Stem material selection please

 

[metengr]

I would suggest you conduct a search on your own using key words- selection of materials for valve stems.

 

[Isha90]

In ASME BPVC.II.D.C-2015,Table 1A for SA-564 type 630 S17400 H1075, Max temp limit section III 650°F, but I & VIII-1 not permitted[NP], Could you clarify why not permitted please.

 

[EdStainless]

The Nitronic 50 has significantly better pitting and crevice corrosion resistance, and it is immune to hydrogen embrittlement (17-4PH isn't).
The galling resistance of Nit50 is an added bonus that often is a great advantage.

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P.E. Metallurgy, Plymouth Tube

 

[metengr]

The most likely reason it is not permitted is that no organization has expressed an interest for using this material in Section I applications.