I have a contractor who is trying to prove to me that he can use 4 times API 610 table 4 allowables in force-moment while appendix F equations he uses factor 2, and is trying to prove that this is allowed for centrifugal hot high pressure pumps according to the following statemnt:

5.5.5 Annex F gives methods of qualifying nozzle loads in excess of those in table 4.

Is that true and can he really go up to 4 time API values, according to this statement?

Appreciating your speedy feedback.
Thanks in advance

Can someone help on this issue since this is the first time I hear that you can use 4 times API610 forces and moments.

Appreciating your prompt replies.

The following para. is extracted from Annex F, API610

a) The individual component forces and moments acting on each pump nozzle flange shall not exceed the range specified in Table 5 (T4) by a factor of more than 2.

Does that mean that we can go upto 4 times API table 5 values on individual forces and moments?

Can someone experiencing this before support on this..

Thanks in advance
Mostafa

Maybe your contractor is confusing statement 5.2.2.1 of NORSOK R-001 which allows 4x API 610 on PN50 pumps and up to 10x API 610 on PN250 pumps. These multiples however only apply to vertical pumps.

R-001 limits horizontal pumps to 2x API 610.

Thanks MoverZ, but where exactly can I say that the limit is only 2 or 4, I can not find anything in API610.
I found an online presentation "http://calgarypumpsymposium.ca/uploads/PDFS/2011Presentations/Calgary%202011%20Nozzle%20Loads%20Presentation.pdf" stating that API610 Annex F can go upto 4 times Table 5 for individual loads but I can not find in API610?

API 610 only says that allowable nozzle shall not over the Table.5

Annex.F gives you the equation that you can combined acting force&moment at the pump in&outlet nozzle, by combining the force&moments, factor 2 will be used for checking each nozzle and combined nozzle(see F.1.2-a,b). But the standard states that this method can result misalignment, and using Annex.F should be informed to owner and vendor.

So before using Annex.F, owner and Vendor should agree that you can use Annex.F to evaluate the nozzle loads.

Also, Annex.F is not exactly let you use 2 times of allowables. If you have a look at the Annex.F, it only gives you the combining equation simillar to turbine alignment check evaluation.

You can get any of these factors available in the codes. However,you need to consult your pump specification first before doing anything else. If your specification mentions it and the pump supplier is providing you the nozzle allowable with any factor you want there is no problem. It is mainly a contractual issue.

Dear Ibrahim Demir, Thanks for your input.
The contract and pumps data sheet is clear in that all hot pumps can go upto 2 API.
The problem is contractor now wants to consider 4 API for individual forces and moments while the remaining equations for moments are 2 API.
Is that acceptable from a code point of view? because he now claims that the code allows that factor of 4.

Who is the contractor? The pump supplier or the piping stress engineer?

If the pump supplier gives it to you with higher factors there is no problem.

If the pipe stress engineer is asking for more allowable, this is the problem.

If the pump is not purchased and you are willing to pay more on higher allowable, yes you can and satisfy the pipe stress engineer. Otherwise the pipe stress engineer needs to provide the piping with more flexibility to satisfy the nozzle allowable, code and contract requirement.

I have to admit that there is a need for high allowable on nozzles in case there is no space for flexibility and the pipe size is large (too rigid to lower nozzle loading in short distance). But all the options need to be exhausted.

If this is the scenario they need to approach your company officially and explaining all the reasons that they cannot manage. So they need to convince the owner management instead of pushing the engineers to accept what they need.

In the Middle East the contracting approach seems to me too difficult to manage since there is no FEED study to see all the problems earlier. So all the problems need to be solved by owners engineer somehow when the problem arises.

If this is the scenario I would ask the contractor to approach the owner management, or let the management know what is happening in writing, ask their approval on the issue.

I'm working with PMT representing the client and the pump has been already commissioned a year ago but has had problems.

A pump specialist made a report that proved that piping is overloading the nozzles, so we made a Caesar check on the files presented by contractor and found out that he did not present API610 report or even nozzle loads check.

When we challenged Contractor to present it he said he can go upto 4 API individual loads while comparing the moment resultants with only 2 API.

The pump vendor data sheet says the pump can go upto 2 API.

So, my question is can Contractor really use API610 Annex F and use 4 x API to compare individual loads?

Just be careful. API 610-11th Ed-2009 6.5.5 says: "Annex F gives methods of qualifying nozzle loads in access of those in Table 5. The purchaser should be aware that the use of the methods in Annex F can result in a misalignment up to 50 % greater than that based on the loads given in Table 5 and can impact equipment installation criteria. The use of the methods in Annex F requires approval by the purchaser and specific direction to the piping designers for its use."

I think this mandatory statement is very clear. The piping designer cannot make decision by themselves without approval by the purchaser and the pump supplier.

The standard name should be API 610/ISO 13709:2009 11th Edition-Sep 2010.

Thanks Ibrahim Demir, since we are trying to contact the pump supplier for a confirmation of this load.

On the other hand the API610 code does not say explicitly that we are allowed to use 4 x API table 5 for individual loads, correct?

Have you asked your analyst to provide the exact reference from API-610?

"On the other hand the API610 code does not say explicitly that we are allowed to use 4 x API table 5 for individual loads, correct?"

NO. The above code Section F.1.2. a) limits the individual component forces on the nozzle flange. These forces shall not exceed the range specified in the Table 5 by a factor of more than 2.

maybe you can install expansion joints/bellows to the piping system to reduce the forces/moment to the pump so it will satisfy the API code allowable.

Yes, he used para. 5.5.5 Annex F gives methods of qualifying nozzle loads in excess of those in Table 4. These methods may be
used if approved by the purchaser and the purchaser should then direct the piping designer accordingly. The
purchaser should be aware that the use of Annex F methods can result in up to 50 % greater misalignment than
would occur using the loads of Table 4.

And also:
F.1.2 Piping configurations that produce loads outside the ranges specified in Table 4 are also acceptable
without consultation with the pump vendor if the conditions specified in F.1.2 a) through F.1.2 c) are satisfied.
Satisfying these conditions ensures that any pump casing distortion will be within the vendor's design criteria (see
5.3.3) and that the displacement of the pump shaft will be less than 380 mm (0,015 in). This clause is a criterion for
piping design only.
a) The individual component forces and moments acting on each pump nozzle flange shall not exceed the range
specified in Table 4 by a factor of more than 2.

Expansion bellows is not an option in this application of high pressure and temperature.

By this post actually I'm not searching for other solutions. I'm just questioning the contractor who says he can use API610 Annex F and apply 4 times API table 5 for individual loads while applying 2 times API for combined bending equations. Can he do that? Can he go upto 4 times API? According to the prior sent message from myself their is no evidence in para. 5.5.5 or F.1.2 that states that he can use 4 times API, correct?

I think it is clear here that you cannot find support for an API 610 limit greater than 2 times Table 5 (using Annex F).
A better way to question the contractor's statement is to simply ask the contractor. Then let us know...

Thanks Dave, since I have already discussed this with contractor and his official reply was the API610 para. 5.5.5 and the F.1.2 that I sent earlier.

That's why I question how I can challenge him that the API610 Annex F is not appropriate.

Lately we decided that since Annex F is conditional on purchaser acceptance. We shall not accept it's use because Annex F might increase deviation of internals by more than 50% and the client is already suffering from pump problems due to internals deviations and pump seizure.

There is no 5.5.5 or F.5.5.5 in API 610 - 11th Edition.

Again, I suggest you challenge your contractor to prove their claim rather than asking the Forum to suggest why the contractor may be correct.

Thanks Dave, but the F5.5.5 in API-11th Edition exists as F.1.2 under Annex F, as I mentioned in my previous message. It is on page 131 of 218. while para. 5.5.5 is actually 6.5.5 on page 31 which is page 39 of 218 in pdf document that I have.

In fact I did challenge the Contractor and he came back with the paragraphs I mentioned.

I used Forum to check if it is really allowed to use 4 times API individual loads since I found on the net this pdf link that says it is allowed:

http://calgarypumpsymposium.ca/uploads/P...resentation.pdf

So I thought maybe Contractor is correct and thus someone on forum faced a similar case and can help out.

Thanks again for your suggestion.