Recent content by nondimensional

Thrust reversal during coast down?

I figured out that this was depth of cover. Thanks for all the input. Appreciate your responses. PS: That was project specific numbering system.

I have a PCCP pipeline profile drawing showing pipeline pressure class as 100-6, 150-10, etc. I understand the first number is a pressure class. As in 100-6 means 100 psi pipe. But what does the second number mean - 6?

Draw a system curve from pump station to the high point only. Draw a second system curve from pump station to final discharge manhole ignoring the high point. At your rates flow, whichever gives you highest head is your pump TDH. If this happens on the first system curve then add a vent...

At higher head on an OH pump, bearing life may change.

Bernoulli says that high velocity is low pressure. As fluid accelerates into the impeller right at the inlet, pressure drops locally creating a flashing effect. This may not be happening in the suction pipe where velocity is relatively constant and relatively low.

If I may ask, what is the ultimate idea of calculating the moment of inertia of the water?

Type of flow conditioning depends on the media you are pumping. What is your pump capacity, type and media? I have seen & used baskets on clean media pumps, single vanes on large sewage pumps, and diffusers on small end suction units.

Friction factor is a function of the distance of the pipe, i.e., f in EPANET is f per 1000 ft of pipe because headloss is for 1000 ft of pipe.

All the measurements, swirl angle, rotations, time averaged rotations, etc are all laid out clearly in HI 9.8. This can be scaled to the existing model as long as the model has a minimum Weber and Reynolds. Then Froude number should be matched.

Artisi, With all due respect, I have just one word - Boeing. They all worked, until they didn't.

Are the engine and the right angle gear on the same baseplate with machined mounting surfaces? If not, I suggest you go with a flexible coupling instead of rigid shaft connection. For lateral and torsional analysis, HI 9.6.8 is a great start. Also, see API 610 section 6.9. With so many...

In the US, if the engine is the prime mover then the engine will have to rated for Tier IV emissions. Check with local emissions requirements. I would start with dynamic lateral and torsional analysis for the whole pping unit as a requirement since there are too many moving parts. A rubber boot...

For academic purposes, velocity head should NOT be ignored. Also, gauge elevation correction should be accounted for as well (z term in Bernoulli's).

Ashtree, I will have to respectfully disagree. 1x water goes to tank. You indicated that 1.33X water will have to be pressurized. The .33X is brine reject. Whatever additional head you put into the additional 0.33X water is still retained by that water, and CAN be recovered. If the tank is...