INSERT MATERIAL AT PUMP CASING REQUIREMENT/STANDARD

[rahardist]

Dear all,
Does anyone know any standards that mentions the requirement for pump casing bolt holes?
I have case that the casing pump inserted by other material for its bolt holes and it doesn't seem fit installed.
Your advice is really appreciated.

GPM : 2722
RPM : 1010
DISC PRESS PSIg : 128

Thanks,

Rahardi

 

[PumpSmart]

rahardist,
What manufacturer is? it is a new pump or new casing?
Do fluid pumped has high temperature, how much? what materials are got casing and seal chamber? How is this insert join to casing? Do You repaired this casing?
API does not allow insert in casing, because for high temperature
probably has different thermal dilatation that is not detected by hydrostatic test or other tests that are made in ambient temperature.
For photos it seems like bolt circle in insert is made wrong.
Please send your input.

 

[JJPellin]

This looks to me like a very poor repair of a manufacturing error. I would reject the case and return it to the manufacturer. These inserts will not have the same strength as a properly machined bolt pattern. Depending on the material of the insert as compared to the material of the case, there could be thermal growth issues, corrosion issues, etc. Our purchase specifications allow for certain repairs to new parts only with the prior approval of our machinery engineers. It is not uncommon to have weld repairs needed to new castings during the machining process. And, we will often approve this welding if we have an approved weld procedure. But, a mechanical insert of the type you are showing would never be considered acceptable in our plant. I don't believe that this would be acceptable to API, either. Refer to API 610 for allowable repairs on newly manufactured pumps.

Johnny Pellin

 

[rahardist]

Dear all,
This casing is new casing from manufacture.
Worthington Pump Sullury 6M-294 from Flowserve.
As mentioned at mechanical drawing (see attachment) there are material (sleeve) inserted between casing and its bolt holes.

Dear Johnny Pellin,
Please capture me the excatly point (page number) in API 610 mentions this requirement.

Thanks,
Rahardi

 

[Artisi]

Soft metal inserts for the casing bolts are the norm for hard metal volutes with bolted casings.
It is not unusual for some suspect looking insert/casing interface and is acceptable as the inserts are normally well keyed into the casing being placed into the mould prior to casting the casing - the picture shown is not unusual and should be acceptable.

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.)

 

[GPRnD]

I mostly agree with Artisi, pump is a slurry pump not an API 610 pump and the X section shows the use of casing inserts (due to it being such a hard material). This is normal practice.

My one concern is the tapped hole on some inserts is very close to the edge of the insert, to the point at which your insert strength might be compromised. I'd probably reject it based on that.

 

[DubMac]

Return the casing to Flowserve at once. This is their hard metal pump that Worthington produced for years out of their Brantford, Ontario facility. Their foundry there has been closed down and the casings are sourced from India now I believe. It is a crap casting and should not have passed their QC.

 

[rahardist]

Dear all,
Thanks for your all suggestion.
I'm feeling the same that's not so comfortable with this part condition. Can you give me strong justification to return it back? Not only by opinion and feeling, but also refer to standards or other regulations. This is important to ensure our management who tend to follow regulation rather than technical understanding.

I believe there are someone who familiar with practical & standards in this forum.

Thanks,
Rahardi

 

[PumpSmart]

rahardist,
API610 is standard for centrifugal pumps on petroleoum refineries, etc and it does not applied in this case.
The problem is that a slurry pump that are state of art pump, most of them are based on ANSI/HI 12.1-12.6 standard for slurry pumps, included Worthington (owned by Flowserve) but for this standard casing are made in one material.
M model is a hard metal unlined horizontal pump.
Casing is usually made of ASTM A532 CL III TYPE A, that have around 600-650 BHN, is very hard, brittle and very very difficult for machining.
So first you have dimmensional mistake.
Second it and two metals joint together, so it tends to have bimetallic corrosion issue, and if the fluid has iones, it will be galvanic corrosion issue (for acid slurries).
Thermal dilatation could be, but usually slurry are not hot enough to became an issue.
Third, sectional view you send, as per this pump casing does not have this insert.
Four, how did they joint those two metals? ASTM A532 is difficult for repaired or welding, they will send you a quality procedure and testing used on this reparation.
I hope this helps

 

[DubMac]

Not sure who you guys bought this casing from; whether it was a Flowserve Rep, Flowserve direct, or a third party that bought from one of those first two and resold to your company.

In any case, you will have to initially deal with who you bought it from and it will have to go back through the food chain and eventually end up on Flowserve. They are a reputable firm and will end up doing the right thing if you pursue through proper channels.

The problem looks to be porosity in the original casting. If you were to see the casting straight out of the foundry, it would have rough cast holes where the inserts were to be placed. The holes are supposed to be just a little smaller than the diameter of the inserts. When the factory receives this rough casting from the foundry, it will machine those rough holes into nice cylindrical holes that the inserts are pressed into (actually with hard metal, they are not machined but ground).

What looks like happened was that the rough holes were a little larger than they should have been out of the foundry. It is not uncommon, especially in the hard metals, to have "porosity" or void spaces where the molten metal did not fill all of the space it was supposed to. They should have caught this (and probably did), and Quality Control should have rejected it had poured another casting.

Make certain you do not install this casing at all. Send the picture to Flowserve and tell them you see evidence of porosity in casting.( send email to whoever you bought it from with pictures, and copy in Flwsrv Regional manager, warranty person from factory it came from, QC MGR in Flowserve's Chesapeake, VA factory, and copy in general Mgr of your plant also.)

If you just rely on the Warranty Dept. to correct, you may retire before they respond. Rattle all the cages you can. They will eventually do the right thing.

 

[Artisi]

If it was down to me, I would fit the casing onto the pump, start it working and forget about it.

If you have strong concerns about its integrity, forward a letter and photo's to Flowserve and whom ever you purchased the casing stating that the case has been put into service and that you expect it to be fully covered by warranty should any problem arise from the casing inserts.

I see no problem whatsoever with the casing as it is.

Although many seem to view it as a problem I disagree with many of the comments, having spent considerable time in the manufacture, selling and application of hardmetal slurry pumps.

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.)

 

[PumpSmart]

rahardist,
There are different opinions, responsibility is up to you.

Anything that can go wrong will go wrong,
Murphy's law.

Good luck! and tell us what finally you decide.

 

[rahardist]

Thank you all for your sugesstions, opinions and concerns.
I decide to contact Flowserve to review their quality control first and see their response.
I agree with the most of comments. Based on our experience, sometime the insert material apart from casing.
Again, thanks..

Regards,
Rahardi