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NFPA 497 says a lot of things. Depending on the valve or vessel type, 15' applies or doesn't. Look at the diagrams. It tells you the answers. I have never heard of digging much further than the NFPA 497 diagrams for hazardous area classification. Remember, NFPA 497 classifies electrical...

Yes, good points made - fully restrained is an idealized condition where as we all know, the soil does not fully restrain (for underground).

LittleInch, what would be the characteristic length for axial strain for a buried/restrained line? Overall length cannot move much in that case.

Hello all, First, someone asked as to where I found the 2% strain reference: ASME B31.8, 833.5, allows for specifically design exceeding yield, and (b) of this same section does specifically mention a strain limit of 2% if you design for exceeding yield (various criteria must be met). Second...

Hello all, I have done stress calculations for multiple years and have a good understanding of hoop vs longitudinal stresses for buried pipelines. Recently I have gotten involved with pipeline strain but I am struggling to understand two key things: First, several codes talk about a 0.5% or...

I think the OP should make an important distinction with their contractor. Things that got get wasted because it is bad (aka not to spec, the wrong size for rock, spills out of the truck, whatever) is not their problem. If seed and/or aggregate is correctly installed and then is later damaged...

Just make sure that you have a good contract with them. Something along the lines of.... They accept financial liability for failures should be satisfactory. They probably just need your seal for permits and the like. I'm sure everyone can come to an agreeable solution. But you should be wary of...

I agree with TigerGuy... Just call the boards of the states you are considering letting lapse. Just tell them that you are considering not renewing because you aren't actively practicing there. Ask them the same questions as far as future renewal and/or fees and then follow up with a summary...

Never seen a published value because... It depends on the means and methods. 20% is comical. I'd reject it and ask why they are allowing that much to go to waste. If they are, that isn't your problem. 5% is probably right, so you should be willing to expect to accept 10%. In the future take...

Creeks are filled in all the time for roadways and then they are diverted to a new trench or a so called stream relocation. But yes I meant to fill in to the original creek bottom.

I am working on a project that involves laying fiber lines for several miles. We will be crossing multiple creeks and drainage ditches. Several of the creeks are extremely eroded with silty bottoms, and we will need to fill them in to allow for crossing. Similarly, several drainage ditches are...

Hello all, Thanks for all the responses. To answer a few questions: 1. Yes on certain projects HDDs/trenchless are feasible/economical, on others they are not. 2. The utility line general permits require that the elevations be returned to the original condition. I don't see how you can argue...

Outside of setting a box culvert or bridge pier into the channel, do you have anything else in mind? For example, I doubt you could pull a permit for riprap in the channel unless it was local to assist scour around culvert/piers. What if you had something more like a linear sewer utility...

Hello all, I have heard quite a bit about stream bank stabilization techniques but nothing about stream channel stabilization. Is formal stream channel stabilization even feasible with the current USACE general permits (I don't think so) as I think any armoring technique threatens to change the...

As stated, you need to carefully read the contracts. Specifically, you should focus on the "exclusions and clarifications" that I hope, for your sake, was included. Once you do that, ask yourself, am I doing anything out of scope. If yes, just be upfront with your customer/client and say per...

It might be semantic and I understand that, but we're engineers and should be speaking in technically correct language. ... We say "pushing gas" because saying that a regulator "passes gas" makes some people giggle [bigsmile]!!!

The regulator's capacity, among other things, come into play when the inlet pressure drop. Maybe they are designed to pass X MSCFH at 500 psi. How much can they pass at 300 psi? Also, depending on the design of the station, you may need something like 50 psid to open both regulators. If you are...

Yes I agree that it is more of a theoretical situation, i.e. that the inlet could drop below the outlet. Obviously, if there is demand on the system, it would draw the outlet pressure down. However, the purpose of the bypass is still the same. Which is to say it lets you bypass around the...

What I mean by in the case that the inlet pressure drops below the downstream MAOP Say for example, you normally get gas at 500 psi and reduce it to 400 psi. Say on a cold day, the inlet pressure drops to 350 psi, your regulators should close until the outlet pressure is below their set point...

High pressure bypasses are fairly common on stations, especially if they have a redundant OPP. They should be manually operated and double valved. One valve should be suitable for throttling service (e.g. a plug valve). If space and budget permits, my recommendation would be to include a full...