MINUTES
TASK FORCE ON STD 526/527
COMMITTEE ON PRESSURE RELIEVING SYSTEMS
8:00 A.M. – 9:00 A.M.Hyatt Regency Central
Wednesday, April 25, 2012Dallas
Roger D. Danzy Chairman, API STD 526/527
Alan West Chairing at the Request of Roger Danzy
- Introductions and registration of attendance (All)
The meeting was called to order by Alan West
- Appointment of secretary to keep meeting minutes (All)
Freeman Self was appointed Secretary
III.Approval of Fall 2011 API 526/527 Los Angeles (All)
The minutes were approved with following changes
a) Section VI – “Roger will resubmit all four items again to the API Secretary for an errata.“
b) Section VI(c ) – Table 15 Table 15 “R” Chrome Molybdenum Steel. For 300 # rating, size should be 6R8 (not 6R10) and 9.5 (not 10.5)
- Review of inquiries for API 526/527
There were no inquires to review.
- Old Business - Standard 527 Errors – Ed Zamejc
API Standard 527 was approved in 1991 and reaffirmed in 2007. When the document was reprinted in 2007, some characters were misprinted in Section 2. The errors are obvious. Ed Zamejc volunteered to review the document. After many years, API finally provided the proof document in the spring of 2012 as an MS Word file. Ed has again agreed to review the document by 1 June 2012.
- New Business for API-526 and API-527
a) For API Standard 527, an inquiry was received from Lon McDaniel about headings in Table 1-“Maximum Seat Leakage Rates for Metal Seated Pressure Relief Valves”. See Appendix for communications.
Roger Danzy has marked the draft standard 4th edition with new words. The discussion was that this is the only standard world-wide that specifies seat tightness so the wording has to be clear. Therefore a task force comprised of Zubin Kumana, Bill Ciolek, Bernd Joergensen and Lon McDaniel volunteered to review and provide revised wording by 1 June 2012.
b) The plan for the API Standard 527 ballot is to (1) review API proof MS Word document by Ed Zamejc for symbols with due data 1 June 2012, (2) clarify item in Table 1 by task force with due data 1 June 2012, and (3) submit document to API for ballot.
c) A task force was proposed to make a systematic study for extending choices of new relief valve sizes for API Standard 526. The intent is to address backpressure in the body bowl. Bernd Joergensen, Emile Tezzo, John Burgess, Tom Bevilacqua, and Hisuo Izuchi volunteered for the task force. No due date was proposed.
- Adjourn
The meeting was adjourned at 8:40 am.
APPENDIX – COMMUNICATION FOR API STANDARD 57 – TABLE 1
From: Danzy, Roger (GE Energy Services)
Sent: Tuesday, January 03, 2012 3:45 PM
To: 'McDaniel, Lon'; 'Danzy, Roger D'
Subject: RE: PSV Seat Leakage Test Criteria
Lon,
Thanks for the email. I will incorporate your comments into a proposal for the next edition of Std 527 and present at the Spring 2012 meeting.
Regards,
Roger D. Danzy
Engineering Manager
GE Oil & Gas – Flow & Process Technologies
Office:+1 318 640 6001
Mobile: +1 318 613 7586
Fax: +1 318 640 6096
E-mail:
P.O. Box 1430 Alexandria, LA 71309-1430, USA
8011 Shreveport Highway, Pineville 71360
From: McDaniel, Lon [mailto:
Sent: Friday, December 30, 2011 6:24 PM
To: 'Danzy, Roger D'
Subject: PSV Seat Leakage Test Criteria
Rodger:
I recently got involved in a discussion over the maximum seat leakage rates listed in Table 1 of API-527. More specifically the question raised was directed towards what leakage rate to use for an API “F” orifice relief valve. Personally I felt like the answer was obvious – that is using API-526 I would classify an “F” orifice as having an “Effective Orifice Size 0.307 Inch and Smaller”. However, from the email discussions (attached below) you will see below there is definitely some disagreement on the subject.
A second item pointed out in the discussion is that the headers in Table 1 say “0.307 inch” when they really should say “0.307 square inch”. I don’t think that is a source of much confusion, but perhaps something that should be cleaned up.
I had two thoughts as to how to eliminate the confusion. My first thought was to add a note to note that the Effective Orifice Size is per the definitions in API 526. However, a simpler method might be to just change the headers to be “API F Orifice and Smaller” and “API G Orifice and Larger”. I personally like the second option better.
I think we can treat this as a suggest change to the standard, but if you prefer I can submit it as an inquiry.
Thanks:
Lon McDaniel
Lead Process Engineer
Anacortes Refinery
Tesoro Refining and Marketing Company
( Phone: 360-293-1671
/ E-mail:
From: Ratzlaff, Dean [mailto:
Sent: Monday, December 12, 2011 8:42 PM
To: McDaniel, Lon
Subject: RE: PSV bubbletight test criteria
I think it should be clarified as API hasn't kept up with the 1962 ASME changes. There won't be many folks around soon to know why and impact. It over-complicates an issue that should be simple and straight forward (must have been written by ChemE's :)
From: McDaniel, Lon [mailto:
Sent: Monday, December 12, 2011 1:06 PM
To: Ratzlaff, Dean
Subject: RE: PSV bubbletight test criteria
Several manufactures are active in API. In fact API-526 and API-527 have been developed to a large extent by the valve manufactures. That does not mean that all manufactures are involved, or that they are all in agreement, or even that within a given company they all have the same level of understanding. Also, the manufactures involvement in 520 and 521 is significantly less and therefore there certainly are opportunities for mismatch.
From: McDaniel, Lon
Sent: Monday, December 12, 2011 2:04 PM
To: McDaniel, Lon; 'Ratzlaff, Dean'
Subject: RE: PSV bubbletight test criteria
Just took a look at the specifics of the question you raised. The issue basically boils down to the definition of “Effective Orifice Sizes” to use in Table 1 of API 527. Not being specifically defined there, I would have to say that the definition(s) in API 526 should prevail. That is The effective orifice area for a API “F” orifice is 0.307 per API-526 table 1. Therefore API-527 leakage testing acceptance criteria for an API “F” orifice should be per the portion of the API-527 Table 1 marked “Effective Orifice Sizes 0.307 Inch and Smaller”. (I think that is consistent with what Robin said.)
Let me know if you want me to pass this on to the API committees. Might be good entertainment value for me, but probably won’t change the way the documents are written.
Thanks:
Lon
From: Ratzlaff, Dean [mailto:
Sent: Monday, December 12, 2011 9:35 AM
To: McDaniel, Lon
Subject: FW: PSV bubbletight test criteria
FYI, Robin's back and just noted below after your message.
It seems the mfrs are confused by the API standards, so maybe you can initiate cleaning them up. Robin said some changes were made in late 60's…..most of us weren't working then and wouldn't know the history or rationale.
______
From:Jentz, Robin
Sent:Monday, December 12, 2011 9:11 AM
To:Ratzlaff, Dean
Subject:RE: PSV bubbletight test criteria
Dean: :"effective orifice size" has a specific meaning for api and is defined in API 526 and API 520. Oddly (or maybe typically) API 527 does not define its terms and even misstates the "effective orifice size 0.307 inch and smaller" should be inch² (an area not a diameter). API 526 correlates API F orifice with an effective orifice area of 0.307 in². API 520 also clearly explains effective area.
Leakage rate for api orifice F (effective area 0.307 in² or less) is 40 bpm for the 15-1000 psig set pressure range. This includes valves with an actual area larger than 0.307 in², but advertised as a F orifice. NB18 does not use the term effective orifice size or area. They refer to the area as "A=nozzle throat area, square inches" (for ASME VIII Div 1 & 2). For Section I, NB18 refers to area as "A=actual discharge area through the valve at developed lift, square inches".
Robin Jentz, P.E. |JACOBS| Process Engineer
Office: 360.685.4458 | Cell: 360.224.3232 | Fax: 360.734.2836 |
______
From:Ratzlaff, Dean
Sent:Thursday, December 08, 2011 3:58 PM
To:
Cc:Jentz, Robin
Subject:PSV bubbletight test criteria
Lon,
Below are the competing exerpts for bubbletight test criteria that I need a referee and/or guidance of who's correct/acceptable. Thanks.
Bay Valve....
Jon is correct in his assessment of the "A/G Crosby" catalog representation and therefore the API effective orifice of the JOS-E design in "F" orifice. The info that I gave you yesterday was an error on my part. However, My opinion, as well as Tim's' is that the intention of API 526 and then applicable to API 527 was always and still is to "F" orifice valves tested at 40 BPM when those valves indeed have a .307 effective area. This is how Dresser understands it and that is why we test "F" orifice (at their direction and in their specification) at the larger than .307 effective area acceptance criteria because it is built as .3568 not .307, as Crosby is .347 not .307. Both Dresser and Crosby effective area may be (REPRESENTED) as being .307 in both catalog sizings for standardization in accordance with API, but they are both in fact larger than that as reflected in actual measurement and as (REPRESENTED) in NB18. I will gladly use do as instructed by the manufacturer, If that is the way our customer would also like to interpret API 526 and API 527.
TYCO/Crosby Everett...
API vs. ASME/NB values can sometimes be confusing, and can result in errors in sizing or other matters such as this when standards are mixed and matched inappropriately. There is no such thing as an 0.337 sq. in. orifice area in API standards. An F orifice, as defined in API standards, is 0.307 sq. in.. Per API, a model 1.5F2 valve such as in question, has a 0.307 sq. in. orifice area. That value is used for sizing, selection and valve specification, and subsquently all related API standard performance testing such as the seat tightness acceptance criteria in API 527. The ASME actual certified effective flow area in NB-18 Cert for this valve is not relevant to this test, nor referenced in API as such. The valve is an F orifice (and ASME actual is also not large enough to qualify as a G), so is 0.307 sq. in. only. Accordingly, 40 BPM is the correct acceptance criteria in this case, per API 527 Table 1 for metal seated valves. If a more stringent seat tightness is required, we may very well be able to meet it with this or other valve product, but that may impact our processes or valve configurations and so would not be applicable to the specific valve in question, or also to other standard material which may have been subjected to excessive (more than standard) testing without our knowledge.
Dresser rep....
You are incorrect about the acceptance criteria for seat leakage. If you look at API 527 the leakage criteria states that effective orifice sizes larger than.307 with set pressures from 15-1000 is 20 bpm. The “F” orifice has an effective area .347 and is therefore 20 bpm. Your IOM references the same charts as API 527 but Crosby inserted the phrase D,E, F orifice size which is incorrect. “F” falls into the > .307 and is therefore 20 bpm for the leakage rate. With the valve you just returned to us having a leakage rate of 30 bpm, it is unacceptable per the acceptance criteria.
Regards,
Dean Ratzlaff, P.E.
Project Manager
JACOBS Engineering
4370 Cordata Parkway
Bellingham, WA 98226
Off: (360) 685-4454
Cell: (360) 201-4899