I have a centrifugal fan directly coupled to the motor shaft. For centrifugal fan, since the air is pulled into the middle of the fan and is flung out due to centrifugal force, the thrust should be pushing against the motor shaft. Maybe I'm mistaken, because I've heard the other way around...
@LittleInch, I went back and did a hand calculation using Re and Darcy factor and I got about Hz = 2', so my NPSH becomes about 34', which is >> than 15' . Given what you said, I was mistaken about the 50 GPM and 230', so that (50GPM at 230' head) is the ideal operating point suggested by...
Thanks LittleInch for reminding me about the worst case. Really appreciate it! I'll also make sure to have a level sensor in the tank to make sure I will always enough water in the tank. The online calculator shows about 0.09 ft of H2O. If I assume 15', I think I have plenty of margin.
I'm...
Thanks for all the replies. After reading up a little bit on NPSH calculation, I gave it a try. I assume the water level is 6' above the pump and I got around 27' of head. Just want to run it by you guys to see if I did this correctly...
The tank will be above the inlet and I have room to adjust the distance between the tank to the pump inlet. I'll try to keep the distance short to minimize the pressure loss.
My guess is 50 GPM. It didn't say anything on the nameplate.
It is a single impeller.
I want to have a water tank on the inlet side to provide enough water column to make sure the pump inlet has about 10% margin over NSHR. Since I'm not a pump guy, I don't have a concept for NSHR for this...
Hello, I inherited a Flowserve pump without any information about the pump.
FLowserve WM inline centrifugal pump
Size: 2x3x12
Head:230'
Capacity:50
RPM: 3505
I've asked Flowserve twice about the pump curve and NSHr, but didn't get any response. I'm trying to design a water tank to create...
Hello, I have a motor that is connected to a dyno with big blowers. Most likely those blowers will dominate the noise for the entire system. I want to measure the dyno with blowers first (background) and then measure the total system (tot). To get the motor sound pressure level (source), can...
Thanks guys for the response. I think it started to make sense to me. Do you guys know how vertical motors address the issues of thermal growth and which direction the shaft is allowed to grow?
Have a few questions about the bearing configuration for vertical motors. Just in case, DE - drive end. NDE - non-drive end
1) Typically, I've read that the NDE bearing takes the thrust load, and the DE bearing is more of a guide bearing. Why is that? Can DE bearing take the load and NDE...
@MagMike, I heard adhesives typically work the best when you rough up the surface to increase the contact surface area. Do you think this is still applicable for acrylic adhesives?
Hi, I have a question about the machined steel plate I received from overseas vendor. The entire plate has a medium grayish finish. I tried to scrape it with a screw driver, and I don't see anything flake off, so I don't think it is a primer. I have 2 questions:
1) After you machined a...
I'm looking into bonding NiCuNi magnet to steel plate using acrylic adhesive. I have 2 questions about surface preparation:
1) In the past, when I get steel plate from overseas, they usually have primer. Should I request bare metal with oil coating? My preference is coating of some kind...
I agree that testing is probably the best way to do this. For a simple straight bi-directional fan, I always assume there's a simpler way to estimate the performance. Maybe I'm just not that familiar with other companies, but when non-fan manufacturers create a fan, do they always send the...
For the same fan OD and rpm, how can we estimate the fan performance (CFM, SP and BHP) when we vary the blade width, like 1" vs. 10"? Fan laws don't seem to account for that.
appreciate everyone's help. Still can't believe the number denoting size is telling you what row to look at until you reach a certain size. [surprise] I'm glad to learn something new today. [smile]
I recently looked up a compression fitting: 1/8" tube fitting x 1/8" male ISO parallel thread. The problem I have is with the 1/8" male ISO parallel thread part. I bought the part and I measured the thread OD and it's a little over 3/8". I got the same thing when I downloaded the 3D model from...
Thanks guys. One thing I'm trying to figure out is whether it is possible to estimate both end points of the fan curve based on RPM and fan geometry. I'm trying to do a very rough estimate of the fan performance. If I can get both end points, I can draw a straight line, and based on my system...
