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impeller diameter range. 3
- Thread starter rajm008
- Start date
Very difficult to help without any data, you know we are all very
smart in this forum - but fortune telling isn't one of outlet strengths.
The best way to find the answer/s is to contact the pump manufacturer or agent with the following, pump brand, model, driver size and speed, duty required and a reason for change.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
smart in this forum - but fortune telling isn't one of outlet strengths.
The best way to find the answer/s is to contact the pump manufacturer or agent with the following, pump brand, model, driver size and speed, duty required and a reason for change.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
LittleInch
Petroleum
how to find out - ask the vendor / look at the pump data sheet / look at the pump curves published.
Difference? Think about a bit more.
tolereance is a +/- dimension acceptable from a given figure
Max and Min are the limits of the size.
E.g. impellor size varies from 110 to 160mm. Tolerance is +/- 3mm from any stated size given by the specific pump data sheet, e.g. 145mm
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
Difference? Think about a bit more.
tolereance is a +/- dimension acceptable from a given figure
Max and Min are the limits of the size.
E.g. impellor size varies from 110 to 160mm. Tolerance is +/- 3mm from any stated size given by the specific pump data sheet, e.g. 145mm
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
Referring the pump curve is the best way to find out maximum diameter of the impeller that can be fitted in the casing, as already said by Artisi and LittleInch. Normally pump curved provided with the pump are plotted by the vendors for more than one impellers. If you see only a single curve, please ask the vendor who will guide you properly
- Thread starter
- #6
Thank u all for the info
I am tryin to get an ul (underwriters labourtires)approval for the pumps which are manufactured in a chinese company.
For expample. One of the pump is 100 gpm at 9 bar.
At first the chinese company gave me a data sheet which shows maximum impeller dia as 342/min as 309 and rated dia 315.
Then i told them at the time of testing instead of testing with the rated impeller we wil test with the max and min impellers so that we get a range of models approved.
When i told this they told me the values they gave for max and min was size tolerance and they gave me new values as max 315 / min 270 .
the logic behind this i couldnt understand.. the tolarence values are more than max and min ?
These questions might find easy for you guys. But i am relatively new to design part and the chinese company i deal with is a big and well established one in pump manufacturing. So when they say it so strongly i thought i should go for expert advice and i am here
I am tryin to get an ul (underwriters labourtires)approval for the pumps which are manufactured in a chinese company.
For expample. One of the pump is 100 gpm at 9 bar.
At first the chinese company gave me a data sheet which shows maximum impeller dia as 342/min as 309 and rated dia 315.
Then i told them at the time of testing instead of testing with the rated impeller we wil test with the max and min impellers so that we get a range of models approved.
When i told this they told me the values they gave for max and min was size tolerance and they gave me new values as max 315 / min 270 .
the logic behind this i couldnt understand.. the tolarence values are more than max and min ?
These questions might find easy for you guys. But i am relatively new to design part and the chinese company i deal with is a big and well established one in pump manufacturing. So when they say it so strongly i thought i should go for expert advice and i am here
LittleInch
Petroleum
Can you check your figures? If you mean 322 max to 309 min then that's prob OK for tolerance, but 342 to 309 is a bit far.
Sounds to me like you've suddenly been given the next impellor range down (270 to 315). However, if the max impellor tolerance range was 322, then the range 270 to 315 is prob OK and while you wouldn't normally aim for a rated diameter at 100% of range, for a simple pump like this it doesn't really matter.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
Sounds to me like you've suddenly been given the next impellor range down (270 to 315). However, if the max impellor tolerance range was 322, then the range 270 to 315 is prob OK and while you wouldn't normally aim for a rated diameter at 100% of range, for a simple pump like this it doesn't really matter.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
-
1
- #8
Could be some misunderstanding between yourself and the Chinese manufacturer, they may believe that the 100gpm at 9 bar is the magic number you are aiming for so their thinking is based on this number.
Initially, I would ask them for a standard set of curves for the impeller diameter range for the pump and also ask if there are other impeller configurations (design) that can be fitted in the pump.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
Initially, I would ask them for a standard set of curves for the impeller diameter range for the pump and also ask if there are other impeller configurations (design) that can be fitted in the pump.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
EdStainless
Materials
Typically there will be multiple impeller diameters and each may also have a different thickness, with smaller ones being thicker.
In this way they can cover a range of performance. Larger/thinner impellers give more head and less flow, but if done correctly the HP will be similar for the smaller/thicker high flow lower head option.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
In this way they can cover a range of performance. Larger/thinner impellers give more head and less flow, but if done correctly the HP will be similar for the smaller/thicker high flow lower head option.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
- Thread starter
- #11
bimr
This is fire pump.
Actually we are a manufacturing company in uae. we manufacture most of the fire fighting equipment here. Now we need a ul approved pump in our name.
So we tied up with this Chinese company agreed we will give good orders if we UL approval for their pumps in our name
So if the impeller dia vary inside the tolerance range the output of the pump should not change right? but if the impeller dia varies btw max and min the power, head , discharge everything changes.
So tolerance can never be a bigger range than the max and min impeller.
dealing with Chinese manufacturer is a really hectic task, Due to communication problem. But to get cheaper products one other way.
This is fire pump.
Actually we are a manufacturing company in uae. we manufacture most of the fire fighting equipment here. Now we need a ul approved pump in our name.
So we tied up with this Chinese company agreed we will give good orders if we UL approval for their pumps in our name
So if the impeller dia vary inside the tolerance range the output of the pump should not change right? but if the impeller dia varies btw max and min the power, head , discharge everything changes.
So tolerance can never be a bigger range than the max and min impeller.
dealing with Chinese manufacturer is a really hectic task, Due to communication problem. But to get cheaper products one other way.
If you need approval for any fire equipment you need to communicate with and comply with the exacting standards that have been established, not ongoing discussions in an open forum.
Complying with FM /UL is a long involved and exacting procedure with tightly controlled specifications and approval including testing.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
Complying with FM /UL is a long involved and exacting procedure with tightly controlled specifications and approval including testing.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
Don't think you need to concern yourself with tolerance of the impeller.
With a reputable pump manufacturer and modern production methods, the impellers will have uniform dimensions over the production run. Each pump manufacturer makes several different sizes of impellers for a specific size of pump. Each impeller will have a unique performance curve associated with the size of pump and the size of impeller.
Ask the manufacturer for a set of pump performance curves for each pump that you desire to have UL listing.
As Artisi posted, obtaining UL listing for a pump will be a comprehensive endeavor and an expensive investment on your end.
With a reputable pump manufacturer and modern production methods, the impellers will have uniform dimensions over the production run. Each pump manufacturer makes several different sizes of impellers for a specific size of pump. Each impeller will have a unique performance curve associated with the size of pump and the size of impeller.
Ask the manufacturer for a set of pump performance curves for each pump that you desire to have UL listing.
As Artisi posted, obtaining UL listing for a pump will be a comprehensive endeavor and an expensive investment on your end.
In my somewhat brief experience with listed firepump applications in Australia, it was noted that in many case "consultants" specified FM /UL approval for no other better reason because they like the sound of it - but in reality they didn't know their arse from their elbow. Final approval for a firepump installation comes from the insurance underwriter - not FM or UL, if they are happy with the pump selection, assembly and installation etc., - they can give approval.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
- Thread starter
- #15
As of now.. my pumps have cleared for testing. All technical data have been reviewed and approved. Testing will happen soon in next month. As sir have told i should not have put up this in open forum. But i am badly short of helping hands. nobody in my company know about pumps. I have somehow managed to get the calculations and drawings with help of ul. But now i am stuck. Then i saw this site. Read some articles all your replies was top class from real professionals. So i knew this is the place where i can get help.
I have to place order now. But to do that i am confused. When they told about two types of max. and min. impeller diameters.no clue for which i will place an order so that while testing i will get a range of models approved. with different gpm and head.
I am really thankful for all your support for taking your time to help a rookie like me.
I have to place order now. But to do that i am confused. When they told about two types of max. and min. impeller diameters.no clue for which i will place an order so that while testing i will get a range of models approved. with different gpm and head.
I am really thankful for all your support for taking your time to help a rookie like me.
Who is going to test and what certification will be forthcoming from the tests.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
- Thread starter
- #17
Testing will be in the testing facility in the Chinese manufacturing company. Representatives from UL and myself will be there to test. Once tests are passed i will get UL certificate for all the pumps. the calculation and paper work was the difficult part but its over now. Once is solve this issue and get proper calibration certificate for the testing equipment from Chinese manufacturer i am good to go for testing.UL ( underwriters Laboratories) US based certification authority which has great value in many countries. In uae only two companies at the present have this certification for pumps. Since its expensive time consuming and very complex process
Sounds like a good result for you and the pump company.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
- Thread starter
- #19
It would be a great achievement for my company and myself. Other companies those who already have are big companies who have a department for pumps itself. for us there is just me. Task gets more difficult when we get it from china. But our price will be very less so yes. once this is over its a great achievement..
Thanks for your support i admire the depth of knowledge you have. I really want to be like that. IF there is any good book or reference you can give me to acquire a deeper knowledge about pumps i would really appreciate it.
Thanks for your support i admire the depth of knowledge you have. I really want to be like that. IF there is any good book or reference you can give me to acquire a deeper knowledge about pumps i would really appreciate it.
There are numerous "good" books on pumps - an internet search will turn these up for you, however great experience comes from "hands-on" and time - possibly as you have just shown yourself. Many people develop extremely good theoretical knowledge which can be very important while others have good practical knowledge - I like to put myself in this category and leave the theoretical discussions to others who are a lot more qualified than I can ever hope to be.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
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