Slurry pump impeller casting
Slurry pump impeller casting
(OP)
This question is about manufacture of high chrome dredger pump impeller casting.
I have received a customer's casting with no drawing for reengineering.
The casing is a simple job, but with the impeller I have a challenge.
Normally, the internal threads for engaging the shaft, is machined on a in situ cast mild steel insert or a cast thread using ceramic cores.
In this case, there is a mild steel insert used with a cap/flange on top.
Normally, there exists a vertical split in the insert during casting ( a "C" section), so that while the casting cools, this insert also closes, like a spring, thus avoiding cracking.
But, I am seeing an insert, without this slot, I am stumped.
Look for some insights or tips about manufacturing such castings.
The casting weighs about 1160 kilos and the material is high chrome iron.
Thanks in anticipation.
I have received a customer's casting with no drawing for reengineering.
The casing is a simple job, but with the impeller I have a challenge.
Normally, the internal threads for engaging the shaft, is machined on a in situ cast mild steel insert or a cast thread using ceramic cores.
In this case, there is a mild steel insert used with a cap/flange on top.
Normally, there exists a vertical split in the insert during casting ( a "C" section), so that while the casting cools, this insert also closes, like a spring, thus avoiding cracking.
But, I am seeing an insert, without this slot, I am stumped.
Look for some insights or tips about manufacturing such castings.
The casting weighs about 1160 kilos and the material is high chrome iron.
Thanks in anticipation.
"Even,if you are a minority of one, truth is the truth."
Mahatma Gandhi.





RE: Slurry pump impeller casting
https://res.cloudinary.com/engineering-com/image/upload/v1500039989/tips/Impeller_Model_1_w86mwx.pdf
"Even,if you are a minority of one, truth is the truth."
Mahatma Gandhi.
RE: Slurry pump impeller casting
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.)
RE: Slurry pump impeller casting
We also made sure that the inserts were hot (usually by making sure that molten metal flowed over them.
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P.E. Metallurgy, Plymouth Tube
RE: Slurry pump impeller casting
"Even,if you are a minority of one, truth is the truth."
Mahatma Gandhi.
RE: Slurry pump impeller casting
This is a large casting, you could almost make the steal insert in two pieces.
Cast in a fairly thin wall part, then mechanically insert the thicker threaded one.
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P.E. Metallurgy, Plymouth Tube
RE: Slurry pump impeller casting
Thanks, and that is how I have been manufacturing impellers. Though a few have moved away from cast inserts, by having ceramic cores with threads. Thus the bore would have cast threads and they are just cleaned on a lathe.
I pursued this technology, but failed , and then gave up as business moved away.
Now, once again after 20 years, I see an impeller that has a whole insert!!. I was stumped.
"Even,if you are a minority of one, truth is the truth."
Mahatma Gandhi.
RE: Slurry pump impeller casting
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.)