I am designing a bolted blind flange on a very low pressure system (less than 20 psi) and I am using BPVC.VIII to determine the minimum thickness of the flange. I am using equation 1 because it will be a flat face flange with full face gasket, so there will be no edge moment. The formula is very...
1503-44, my version of the code (2012)shows how to calculate the failure stress, which uses similar equation to yours above. It says to convert it to the failure pressure, Pf, the formula is Pf = 2*Sf*t/D, which uses the nominal thickness. Does this seem right?
Hi,
I am using ASME B31G to estimate the remaining strength in a corroded area of a pipeline. I have all the info I need (corrosion depth, length, etc.). When calculating the hoop stress of the pipe at the operating pressure, should you use the nominal pipe wall thickness, or the remaining...
Hi,
I am still new to using the AMSE BPVC, and I am a little confused by the bolt load calculations. I understand that you need to calculate the bolt loads required for the design conditions (Wm1 and Wm2) and select the greater of the two to use as your minimum required torque, however I don't...
GBTorphenhow,
Thank you for the advice! This is what I thought, but wanted to confirm. Just out of curiosity, do you know why lugs aren't designed to be the full width of the valve? Is there a benefit to this?
TugboatEng,
I'm just curious because I'm wondering if lugged valves can be installed between flat face cast iron flanges. I'm early on in my career, but I've only seen lugged butterfly valves where surfaces of the lugs does not come in contact with the flanges, which I would assume you...
Hi,
Are lugged valves available in raised or flat face? It seems that every lugged butterfly valve that I come across has a flat retainer ring, but then the lugs are offset, such that the lugs would not come in contact with the flange when they are bolted together. This to me seems that it would...
Thank you for the responses. The piping, flanges and valves were all replaced at the same time. I'm not sure what gaskets are in there right now and unfortunately the site is not accessible for the next couple months. The reason I was looking into spiral wound gaskets was because it was...
Littleinch, this equipment was installed before my time, so I am not sure why a flat face SS flange was used. It is flanged to a SS lugged butterfly valve.
I will take a read through of appendix B.
Hi. Does anyone know if it is acceptable to use spiral wound gaskets with flat face flanges? Is there any standard that covers this? I know that spiral wound gaskets are typically used for raised face flanges, however I'm wondering if I can get away with using a spiral wound gasket with an inner...
Littleinch, it’s in a valve shed, so it’s not going to get rained on or submerged in water, but it is a damp environment. There’s typically a couple inches of water on the floor (not higher enough to touch the valve).
Thank you for your input. I'm still waiting to hear back from the gasket supplier, so that I can determine if class 1 screws will suffice for this application. I always hear mixed opinions on using stainless screws with stainless tapped holes, so I wanted to see what people thought about it on here.
Hi,
I am looking to install a lugged butterfly valve with a 316SS body. I'm trying to decide if I should use B7 or B8 (class 2) Hex bolts for this application. The flanges are also 316SS. My concerns with using B8 bolts are the lower strength, and the risk of galling (even if using a...
LittleInch, I wasn't around during original construction and its not shown in the drawing, however I do believe that it is an orifice plate between those two flanges.
Yes, they were all zeroed for altitude. I'll have to get that gauge relocated to see if that fixes the problem.
Thanks all for the great insight. See photo below of pump and piping off the penstock. I think I'll start with replacing the gauge first to see if its just a simple fix. If that doesn't resolve the issue then I may need to try a flow straightener or rearranging piping. Yes, I know the steel hose...
