Draft Meeting Minutes (Revised May 1, 2010)
TASK FORCE ON ISO-23251/STD-521
COMMITTEE ON PRESSURE RELIEVING SYSTEMS
8:30-2:30 p.m. Hilton Riverside Hotel
Monday, April 26, 2010 New Orleans, Louisiana
Brad Otis Convenor ISO 23251
Mike Porter, Chairman API STD 521
E. Zamejc Project Leader ISO 23251
I. Introductions and registration of attendance (All).
The meeting convened at 8:30 am at the Versailles Ballroom. The meeting was jointly led by Mike Porter and Ed Zamejc. Those present introduced themselves around the room. The yellow registration sheet was signed, and the distribution list was updated by those present. The number of attendees was 55.
Everyone should have brought their own copies of the documents (hard or soft copies), as API is no longer providing those.
II. Appointment of secretary to keep meeting minutes (All)
K. Cagle was appointed secretary to record the meeting minutes.
III. Review of meeting minutes
a) Fall 2009 ISO 23251/API 521 Dallas Meeting
Take out word “acceptable” for risk, at the end of Section III. This will now read:
It was noted that the “Toxic release” wording (proposed new clause) will not provide risk criteria as that is for the Users to decide.”
b) January 2010 ISO- 23251/API 521 Houston Meeting (held January 14 & 25)
The term “pressure-relief devices” has a hyphen and is consistent with the ISO documentation. If this is a carry-over from ISO, we will leave the hyphen in.
It was moved and seconded to approve both sets of minutes with these minor comments. The minutes were approved by the Task Force.
IV. Review of inquiries / correspondence on API 521/ISO 23251
Technical Inquiry 521-1-06/07 [521-2007-06]
Concerning tube rupture scenario (70 bar differential, or high pressure side > low pressure side hydrotest pressure) a response was written by Ed Zamejc. One of the operating companies did an analysis, and the low pressure side did not exceed the low pressure hydrotest pressure. This example used gas on the high pressure side and liquid on the low pressure side. Another operating company also did an analysis and found that the pressure exceeded the hydrotest pressure of the low pressure side as a short-duration (water hammer like) spike. We would like more details on these analyses. What was the duration and how high was the pressure spike? The comment from Brazil was: could we accept overpressure of twice the design pressure? The observation was made that FRP piping on the low pressure cooling water side, dynamically, cannot withstand the same as carbon steel piping. The following wording was added to our response: “Additionally, consideration should be given to the low-pressure side piping design and support.”
Technical Inquiry 521-A1-2008-1
Concerning nine drums connected to the same vent gas system (fire case), the group decided that it was consulting in nature. Mike Porter stated he would have a response by the fall meeting.
Technical Inquiry 521-A1-2009-2
This topic is concerning fractionating columns--what is the composition of the liquid on the trays? This could be considered consulting, as we do not define composition anywhere else in the document. Those present agreed that the following wording is ready for a ballot: “It is up to the User to determine the composition based on the specific fire scenario and equipment configuration.”
Technical Inquiry 521-A1-2009-3
Three questions were submitted as part of this inquiry.
1. It was noted that some parts of the subject graph (Figure 18) may have been corrupted when made into an ISO document. The error in the current edition will be fixed (refer to Fourth Edition API 521 for the correct nomenclature).
2. In the case of calculations involving pressure-relieving devices, the upstream pressure should use the inlet pressure to the relief device during the relieving event. The downstream, pressure should use atmospheric pressure when venting to atmosphere while the backpressure at the pressure-relief valve should be used when discharging to flare. See ISA standards, IEC standards or consult noise specialists for additional details on accounting for noise attenuation through pipe walls, and combining noise sources in the outlet piping. Ed Zamejc stated that he would copy the relevant excerpt from Baranek’s book on noise onto the API SharePoint site. It was noted that pipe exit would be a second sound source if flow is choked at the exit. However, because this is not a noise standard, only is a simple approximation is given.
3. What do the numbers 48 and 16 represent? Original equation was based on a relieving pressure of 48 psia and downstream of 16 psia, instead of bar pressure. Units are in absolute pressure and they cancel out in the example given. Action item assigned to E. Zamejc is to re-cast the example discharging to atmospheric pressure in SI and customary units.
V. Old Business
a) Review Action Item List
After the break, E. Zamejc reviewed the Action Item status. The Task Force went through the Action Item spreadsheet (starting on p. 20 of the meeting attachments). As stated in the previous meeting minutes, it was agreed that a draft of these action items had to be completed by this meeting (Spring 2010); otherwise they will be either dropped or delayed until the next edition, where possible.
As an explanation of the color code for the Action Item table: the brown items indicate a draft was submitted for the Task Force to review and approve. Blue represents items that are reviewed, approved and incorporated into the document.
Action Item 6--Completed.
Action Item 7--E. Zamejc set up examples using both units, and these are in the attachments. A draft was submitted for the Task Force to review and approve.
Action Item 8--Georg Kiese submitted a draft for the Task Force to review and approve.
Action Item 11--Z. Kumana submitted a draft for the Task Force to review and approve.
Action Item 13--Completed.
Action Item 14-- A draft depressuring curve for carbon steel was completed and incorporated into the Annex A revision for review and approval.
Action Item 15--Completed.
Action Item 16—A draft of Annex A was completed for review and approval. Pool fire test data, recommended values of parameters of the analytical method for different fires, and comparisons of the empirical and analytical methods were included in the Annex.
Action Item 19-- Completed.
Action Item 20--Open item ----was assigned to M. Ali. At the recent DIERS meeting, an OSHA representative stated that they look at API 521 as RAGAGEP (Recognized and Generally Accepted Good Engineering Practice). However, OSHA have not addressed whether references cited in API 521 are also considered RAGAGEP. E. Addison stated that EPA cites specific codes and standards but not their references. Everything done so far would avoid addressing how to handle the citation question, as references could cite other references, and so forth. The document citations are references currently listed in the bibliography. There are only two "normative" references in the document now---ISO-4126 and API RP-520 part I. It was noted that bibliography documents are informative only. It was recommended to review the references as we publish the ISO documents. How do we communicate clearly that these are informative only? E. Zamejc to obtain wording and guidance from ISO TC67-435 Policies and Procedures Guide. To summarize----1) It was agreed that all the references in the bibliography are informative. 2) Obtain wording/guidance from ISO TC67-435 to ensure these are considered informative only.
Action Item 21--A committee representative from Brazil had asked to add a reference from Hydrocarbon Processing Magazine concerning tube rupture. Bob McMiccan had suggested that we check the article before we include it as a reference to ensure there are no conflicts with current guidance. It was noted that reviews of all of the references in the Bibliography would take a huge amount of time. It would be ideal to reference a specific paragraph in the article. Some of those present have been using the subject article as a reference so it was agreed to add the reference.
Action Item 27--Author has not been heard from and no one volunteered to take this over. The proposal was made to close the item, and it was agreed, no action would be taken.
Action Item 28--A draft is available for the Task Force to review and approve.
Action Item 37--Closed.
Action Item 38--Closed.
Action Item 39---To make clear, is this user of the document, or owner-operator? Entire committee needs to review.
Action Item 40--A draft is available for the Task Force to review and approve.
Action Item 41--A draft is available for the Task Force to review and approve.
Action Item 43-- Concerns setting mechanical design temperature for flare headers. We do have a draft from Don Eure.
Action Item 44---Action Item is Open and due by summer 2010 by D. Lopez who will send draft rewording for review.
Action Item 45--A draft is available for the Task Force to review and approve.
Action Item 46--Completed.
Action Item 47---Action Item is open and Bob Schwartz is working on this. The recommendation is to cite American Flame Research Committee paper as a reference. E. Zamejc action item to share paper with the Task Force.
Action Item 49—Action Item is open and Don Eure to provide by end of May or item will be closed.
Action Item 50, 51, 52--Drafts submitted.
Action Item 53--Open - topic is flame stability.
Action Item 54--Draft was submitted for review.
Action Item 56--Completed - E. Zamejc moved calculations into Annex C.
Action Item 57--open concerning seal drum drawing.
Action Item 58--C. Shepard submitted draft wording on vertical seal drum design.
Action Item 59--Draft was submitted for review.
Action Item 61--Draft was submitted for review.
Action Item 62-- Document may need additional guidance if 70 bar differential is exceeded, yet still meets 10/13 rule. Path forward is to close this item, and no changes will be made to the document to address this, at this time.
Action Item 63--Open, reassigned to Master Editor. There is an inconsistency in the document so there will be no new guidance.
Action Item 64--reworded, draft completed for review.
Action Item 65--Open - table update is needed, for maximum insulation temperatures, to explain the basis for temperatures, and revise language for limits to temperature. May 31 is the deadline, and if not completed, it will be dropped. Planned survey will be deleted. Draft guide for dual insulation will be due by end of May.
Action Item 66--Open - R. Danzy has sent suggestions to P. Henry, and item is in progress.
Action Item 71----will be closed out per J. Straitz.
Action Item 72---address steam-out scenario during maintenance. E. Zamejc has provided a draft.
Action Item 74--keep fuel-controlled fire wording as simple as possible. Ventilation fires will have 1-2 qualitative sentences. There is a lot of uncertainty in this field. Reference will be included from Europe for indoor fires. Proceeding down that path is fine with the Task Force.
Action Item 75--Open – Per Salatar to provide figure.
Action Item 77--draft submitted for review.
Action Items 79 & 80--completed.
Action Item 81--has been reworded, but to be re-ballotted.
Action Item 82--(example is LPG refrigerated system) F. Self said use API 2000 below 1 bar pressure. Reason for not using API 521 for low pressure is because it does not reach sonic flow. D. Lopez would check with his specialists to see which document they use, and Task Force would review the basis of that. What is in current edition? ISO 4126 goes down to half a bar but ISO 28300 goes to one bar. Does Task Force agree which standard to use in between half and one bar gauge? We could delete the entire sentence concerning pressure limits in the Scope. Wording could prohibit using this standard for the flares. Document could apply to equipment less than one bar gauge, except for fire. Consensus was to leave it up to the users to decide which one to use. Close out this item pending additional information from D. Lopez.
Action Item 83---change due date to May 31, 2010---T. Bevilacqua will send out for review, revise per comments, and send to E. Zamejc. E. Zamejc will be copied on the first send-out. Let Mr. Bevilacqua know if anyone wants to give their comments.
Action Item 84--Equations (56) & (57) express pressure differential and not absolute units. To be modified in the document
b) Work Item List
Work Item 1---Claus plant relief protection, work group formed, withdrawn.
Work Item 2---Bypass valves open - Withdrawn.
Work Item 3 -----Fire exposure of jackets, withdrawn.
Work Item 6----Relief discharge near heliports, J. Sawchuk will submit by May 31, 2010
Work Item 10---Cracking of heavy oil in fire scenario, F. Self will provide draft by May 31, using J. Hauser’s input; if not done by then use Hauser’s draft.
Work Item 13----Concerning calculating backflow through check valves. We have existing text, as well as Bob McMican’s re-wording, and Bob wanted to reword again. May 31 is the deadline, and the document will remain as is, if we have not received further revisions by then.
Note----These drafts have not been incorporated into the document.