Recent content by bizkitgto

I am having a hard time understanding how Back EMF works in induction (where the slip is very low, say 1%) and synchronous motors. My understanding of Back EMF is that back EMF is directly proportional to the motor's speed. As the motor spins faster, the back EMF increases, opposing the applied...

Stress analysis can tell you if you exceeded yield stress if you know the pressure /applied stress during the over-pressure event. Assume in this hypothetical case over-pressure protection failed (blocked in).

Thanks for the reply. Can you elaborate on this part more, specially how the "load is shared by adjacent material" (is that a change from before yielding?)?

Can you explain why yielding doesn't happen at SMYS? I was under the impression that SMYS is when plastic deformation starts... Edit: spelling

Assume yielding occurred due to overpressure in piping, and it is known and real, measured via pressure transmitter (DCS).

In a overpressure situation where design pressure is exceeded, typically stress analysis is done to confirm there was no yielding. In some situations, hydrotesting is done at yield stress. What if yield stress was exceeded? ASME B31.3 doesn't specify when to replace piping after yield stress...

N2 is heavier than natural gas right, wouldn't you be better off purging the nat gas from the top of the tank, and force the N2 out the bottom of the tank through the pump column via the dummy pump? I don't think you can flow natural gas into the bottom of the tank and force the N2 out the...

I’m working on a project where we have a large LNG Storage Tank at an LNG Facility. There are several submerged pumps, and each pump can be pulled out and replaced with a dummy. It also calls for a “dummy pump” to be installed for the LNG Cooldown/first-fill. The dummy pump appears to be a...

1503-44 - please see my response below: ********** Firewater system full of air? How does that actually work. Wait 20m getting it primed while expelling air? Does the air get blown out of the pipes onto the fire? What's going on here? ************ >> these are vertical turbine pumps, they...

LittleInch - please see my response below, started with a “>>”. I don’t know how to attach a sketch on my phone, I’ll try later. ************* Which pumps are these? The fire water pumps or some secondary pumps feeding the fire water sump pond? you say the pumps will "draw fire water..."...

We are installing a new firewater system as part of a plant expansion. The new firewater system will draw fire water into a sump fed from storm ponds, this sump will feed both main fire pumps and jockey pumps. The pumps are all vertical centrifugal pumps. Since these pumps will always be...