Hello All,
I have noticed that in reading through different specifications API has no qualms about using the term “Sour Service”. Likewise, it is a term that is used industry wide (oilfield) as an indicator that MR0175 should be consulted during the material selection process.
On the other...
Thank you for your answer redpicker that makes sense. Certainly since they are paying for it I'm willing to do it, but the reason I'm asking is to find out if the difference is profound enough to cause me to change our own procedure. I guess I'll just do some testing to see if the end result...
I recommend joining all relevant organizations that issue standards that apply to your product. NACE, API, MSS, ASME, ASM International, etc, and taking every opportunity your employer will give you to attend classes given by those organizations that pertain to your product. It's an invaluable...
Peterlgg has a very valid point about the misconception that valves need to be greased. I would add that when you pump grease into a valve cavity it will fill the cavity and then extrude by the seats and into the valve bore. That grease is now an adhesive that is going to trap any trash as it...
Hi all,
I have a customer who has specified the above heat treatment procedure for some forged material. I am interested in getting some opinions on what purpose the normalizing might serve. We typically only preform the latter three heat treatments and end up with a product with good...
MECHGU,
Since my original post, I have learned that there are many different things that can affect the notch toughness of 41xx series steels, probably more than can really be mentioned in any kind of detail in this type of post. The two main things I have found so far are as follows:
First...
Hello All,
I am trying to establish minimum acceptable and minimum average Charpy impact values (ft-lb) for AISI 4140 at -50F.
The material will be Normalized, austenitized, quenched, and tempered. It should have approx. UTS of 115 ksi, YS of 99ksi, and hardness around 21 HRC.
The material...
gerhardl,
"As the manufacturor obviously is design responsible for this (uncommon?) solution, he is also the one responsible for the valves performance in the system."
The manufacturer just designs the valve, and the customer must specify the particular way in which pressure equilization is...
sw71im,
It could be caused by a hundered different things. You are going to have to be more specific about all the details of your specific application before anyone can make an educated guess as to what your problem is.
Best Regards,
VRF
Pipexp,
I am not really familliar with RP14C, but I would say that an acceptable leakage rate should be determined not by reading an API Spec, but by carefully examining all aspects of the system to determine the implications of leakage. There are many applications where NO leakage is...
Lozzi,
First I would suggest selecting a relief valve that has a manual override feature. This way, if the relief valve is not triggered automatically, but the gate valve is still difficult to open, you can manually relieve the pressure.
Second, I would suggest that you set your relief...
321GO,
Stem shear calculations are important, sometimes the discs are fastened to the stem with a pin or pins, so you might have to calculate the shear values for the pins. Flow rates are important. Calculating flow coefficient(Cv) is important. Torque requirements at various pressure...
321GO,
There are obviously many different materials used, based on the intended application, however I would say the most common are:
Body: Ductile Iron, Cast Iron, Cast Steel (WCB)
Stem: 416SS, 316SS
Disc: Ductile Iron w/ Nickel plating, Aluminum Bronze, 316SS, Nylon coated Ductile Iron...
Lozzi,
Can you give a description of the valve? Ie body, trim, seat, pressure class, and design (6D or 6A). Also state the design and working pressure.
Best regards,
VRF
Edstainless,
Thanks for your reply.
In that case why are the duplex grades so resistant to pitting? Don't they have ferrite content of like 35-65%? And aren't the elements which promote ferrite formation also the elements which enhance pitting resistance?
Not arguing your point here, just...
Dr. Mcguire,
Is the critical pitting temperature also increased for CF8M as opposed to wrought 316? If so, is the increase appreciable?
I've read that foundries like to shoot for around 8% max ferrite due to the decrease in hot tear deformities, is there a functional disadvantage to shooting...
