Document 0gnEXdpe2XnZQJ9rx9abm8EV

ABD00230689 CONFIDENTIAL ; RUPTURE DISC/RELIEF VALVE PRACTICES MANUAL VISTA POLTMERS INC. ABERDEEN, MS UPDATED SEPTEMBER 16, 1985 ABD00230690 RUPTURE DISC/RELIEF VALVE PRACTICES MANUAL ::n a Ecmdent i i TABLE OF CONTENTS I. INTRODUCTION II. RUPTURE DISC ORDERING AND PRE-INSTALLATION CHECKOUT A. Specification of Rupture Discs B. Lot Inspection and Pre-Testing C. Recordkeeping III. RUPTURE DISC INSTALLATION A. Installation in Holders B. Pressure Testing in the Shop C. Installation in the Plant D. Pressure Checking After Installation on the Reactor IV. RUPTURE DISC REMOVAL A. Rupture Disc Changeout B. Destructive Testing V. RECORDKEEPING VI. TRAINING VII. RELIEF VALVES A. Reactor Relief Valves B. Other Relief Valves in Vinyl Chloride Service C. Recordkeeping ABD00230691 Rupture Disc/Relief Valves Practices Manual Page 1 I. INTRODUCTION & *\ CONFIDENTIAL Sacelon 61*65 (b)(4) of the National Emission Standards for Hazardoua Air Pollutants requires that a rupture disc be Installed underneath any relief valve In vinyl chloride service alnlalze leakage through the relief valve to the atmosphere. In accordance vlth this requlrenent, Vista Polymers Inc* has Installed a large number of rupture discs In vinyl chloride service throughout the plant. In addition to preventing relief valve leakage, rupture discs also serve the vital function of pro tecting the relief valve from polymer buildup on the relief valve seat* which could hinder the proper functioning of the relief valve In aa emergency* In either case* proper functioning of the rupture dlsc/rellef valve combination Is essential for plant safety. This program has been developed because of the importance of maintaining the integrity of rupture discs during their handling and installation* Adherence to the procedures outlined in this manual will help to ensure that the chance of rupture dlsc/rellef valve malfunctions will be mini mized* and that thorough documentation will be available whenever such a malfunction does occur. This documentation may become extremely critical in the event of a VCM release caused by a premature rupture disc failure or other process upset conditions. ABD00230692 A Rupture Disc/Relief Valve Practices Manuel Page 2 : CONFIDENTIALj II. RUPTURE DISC ORDERING AMO PRE-INSTALLATION CHECKOUT A* Specification of Rupture Discs All rupture discs in VCM service are listed on Table 1. The following specifications should be noted on the purchase order when ordering these rupture discs. 1. Disc size (specify). 2. Type S-90. 3. Nickel material. 4. OX Manufacturing range. 5. Burst pressure (specify). 6. Burst temperature. 7. Certification of performance. 8. ASME code stamped and certified. 9. Test each disc to 90X of rated burst pressure. 10. Replaces lot no. . (specify). 11. Serially number all'discs in the lot. B. Lot Inspection and Pre-Testing All new rupture disc lots received at the plant receiving dock must be thoroughly inspected and tested before they are moved to the storeroom* The following procedures are to be used when new rupture disc lots are received at the Plant: 1. When a lot of rupture discs arrives at the receiving dock* care must be exercised when unloading the discs from the truck so as not to damage the discs. ABD00230693 Rupture Disc/Relief Valve Practices Manual Page 3 CONFIDENTIAL7- II. RUPTURE DISC ORDERING AND PRE-INSTALLATION CHECKOUT - Continued B. Lot Inspection and Pre-Testing - continued 2. The receiver oust notify Processing Engineering that there are new rupture discs at receiving, and a Process Engineer or other trained personnel will count the number of discs in the lot and inspect each individual disc for flavs. 3* A flaw in a disc Is defined as follows: a* Any scratch or indentation which can be felt on the opposite side of the disc. b. Any irregularity in the shape of the domed portion of the disc that can be seen with the eye or felt. c. A pinhole or scratch which could cause the disc to leak. d. A disc without a tag. e. A disc that will not fit the pins of a holder. f. A disc that is labeled differently than the other discs in the same lot. 4. Flawed discs must be removed from the lot and returned to the manufacturer. Discs which pass inspection are initialed on the box by the inspector. 5. Rupture discs which are to be Installed on vessels in VCM ser vice must be approved by lot before they can be placed in the storeroom. One disc from each of these lots will be sent to the maintenance shop and burst using the procedures specified in the destructive testing section of this manual. ABD00230694 Rupture Disc/Rellef Valve Practice* Manual Page 4 CONFIDENTIAL1! '------------- . __________ II. RUPTURE DISC ORDERING AND PRE-INSTALLATION CHECKOUT - Continued B. Lot Inspection and Pre-Testing - continued 6. If any rupture disc doe* not buret within 5X of its rated burst pressure, the entire lot from which the disc was taken oust be returned to the manufacturer. Maintenance must notify receiv ing that these discs have either passed or failed this test. 7. Rupture disc* which pass Inspection and testing are ok'd for placement In the storeroom. Rupture disc boxes which have not been Initialed are not to be placed In the storeroom. C. Recordkeeping Administrative Services must keep a record of rupture disc receiving and Inspection data. An example Logsheet la attached. This Information oust be stored In the plant for a period of at least two years. III. RUPTURE DISC INSTALLATION A qualified maintenance installation observer must be present during all phases of rupture disc installation (vinyl reactors only). The Mechanical Superintendent will keep an updated list of qualified maintenance Installation observers. A. Installation In Holders All rupture discs must be Installed In the holders according to the manufacturer's specifications. These written specifications come with each rupture disc. The following steps outline the general procedure which Is to be used when Installing rupture discs in holders: ABD00230695 Rupture Disc/Relief Valve Practices Manual Pag# 5 III. RUPTURE DISC INSTALLATION (Continued) A. Inatallatlon in Holdara - continuad 1. Befora a dlac la placad In tha holdar, tha disc, cha holdar and tha holdar bolea must ba Inspected for flavs. 2. Flava ara defined as follows: a. A disc that has any of tha defects listed In Section II (B)(3). b. A holdar face that la covered with dirt or debris, or Is deeply gouged such that It will leak when Installed. c. Set screws that ara galled or cannot ba screwed into tha holdar by hand. d. A holder with a damaged bite ring. A holdar Is considered damaged If there are Indentations or flat spots on the bite ring. This is determined from a visual inspection of tha holdar. Also, the height of the bite ring oust be checked. This Is done by the Inspector running his fingernail around tha bite ring. Tha bite ring has sufficient height to be reused if It holds the fingernail all the way around the circumference of tha bite ring. 3. Flaw components must not be Installed in the Plant. 4. Place tha disc In the holdar and hand Install the holder bolts. Using a torque wrench, tighten the holder bolts to the torque specified by the manufacturer. This tightening must be per formed in at least four passes; l.e. 25Z, 50%. 731 and 100Z of the final torque. A criss-cross tightening pattern must be used when torquln^; the bolts. ABD00230696 Rupture Disc/Relief Valve Practices Manual Paga 6 III. RUPTPM disc ihstallatioh - Coneinuad confidential A. Installation in Holdara - contlnuad 5. Vhan the installation of Cha disc in tha holdar is complata, visually inapact tha disc again to sea if it has bean distortad or otharviaa damaged* 6. Ruptura disca oust not ba ranovad from tha holdara aftar installation, otharviaa tha ruptura disc oust ba dlscardsd. B. Prassura Taatlna in tha Shop All raaetor ruptura discs ara to ba prassura tastad in tha maintananca shop to 90Z of thair ratad burst prassura bafora being installed in tha plant* The following tasting procedure oust be . used when pressure tasting ruptura discs in tha maintenance shop. 1* Clean tha flanges of the test bench and tha faces of the rupture disc holdar where the two surfaces meat. Use an asbestos gasket between the flange and the holder. 2. Install the holder on the test bench and tighten the bolts in a criss-cross pattern, making several passes on each bolt. 3. Warn nearby personnel that a ruptura disc is being prassura tested* A* Using pressurised air, slowly open tha test valve and pressurise the space underneath the rupture disc. Increase the pressure to 90X of.the rupture disc burst pressure at 72F. 5. Slowly depressurise the space underneath tha ruptura disc and remove the assembly from the test bench. If tha disc appears to have been distortad or otherwise damaged during tha test, do not install tha alsc in the plant. ABD00230697 Rupture Disc/Relief Valve Practices Manual Page 7 III. RUPTURE DISC INSTALLATION - Continued CONFIDENTIAL!( B. Pressure Testing In the Shop - continued 6. If a rupture disc bursts prematurely (less than 90Z of Its rated burst pressure) or Is damaged by the test, the disc must be given Intact to Process Engineering. 7. The calibration of the test bench pressure gauge vlll be checked with a dead weight pressure gauge every six months. C. Installation In The Plant Rupture disc assemblies must be Installed In the plant accordingly: 1. Before installing the holder assembly between the companion flanges, thoroughly clean the flange faces with a putty knife to remove any solid buildup or debris. 2. Check to see that the flange faces are not gouged or otherwise damaged. Place the rupture disc between the flanges, with the bulged-out side of the disc facing the process. 3. On reactors, use asbestos-type gaskets only. Flexatallk gas kets may be used elsewhere in the plant if desired. 4. When tightening the companion flanges, torque the bolts to the manufacturer's specification using a criss-cross tightening pattern. Make at least four passes on each bolt. D. Pressure Checking After Installation on the Reactor After a rupture disc has been Installed on a reactor, the reactor will be pressure checked before It Is charged. The reactors will be pressure checked to 90 of the pressure of the lowest rated 2 rupture disc on the reactor or 170 0/in , whichever pressure Is lower. ABD00230698 Rupture Disc/Relief Valve Practices Manual Page 8 CONRD0ITIAL'! III. RUPTURE DISC INSTALLATION - Continued D. Pressure Chocking After Installation on the Reactor - continued The pressure check must be witnessed by an approved pressure check observer. A list of approved pressure check observers Is kept on the Vinyl Shift Supervisor's bulletin board. The pressure checking consists of filling the reactor with water and then increasing the pressure in the reactor to the desired pressure per established procedures. The operators Involved must be extremely careful during pressure check procedures not to burst or damage a rupture disc. Bursting a disc during the pressure check will cause reactor downtime to change the disc. A disc can be damaged by hydraulic shock if the reactor becomes liquid full during the pressure check. A damaged rupture disc may burst at lower than the rated pressure* causing leakage through the reactor relief valve. In addition* a damaged disc may not burst at the rated pressure, which could allow a reactor to overpressure. The pressure check observer must witness the pressure check from the field and must verify the final reactor pressure. The reason for the pressure check, the signature of the approved observer, the final reactor pressure, and other test find ings will be noted in the reactor pressure check log kept in the Vinyl control room. ABD00230699 Rupture Dlsc/Rallef Valve Practices Manual Page 9 IV. RPFTPRB DISC REMOVAL --------------- -----tn CONFIDENTIAL A. Rupture Dlac Chanaeout Rupcura dlaca ara Co ba removed from service and chaogad accord ingly: 1. Any rupcura dlac which fails In aarvlca must ba changad aa aoon aa poaalbla aftar le la dlscovarad chat tha dlac haa fallad. 2. Any rupcura dlac which la ballavad to ba covarad with raaln or otherwise daaagad muse ba changad aa aoon aa poaalbla. 3. All rupcura dlaca on raaccora will ba changad ac laaac onca ovary cwalva moncha. 4. Whan a raaccor is takan out of aarvlca for condanaar drilling, cha condanaar rupcura dlac(a) will ba removed or guard(s) will ba InaCallad ovar cha rupcura dlac nozzle(s) befora cha drill ing oparaclon la acarcad. 5. Any rupcura dlac which falla In raaccor aarvlca muse ba glvan co Procaaa Engineering. B. Daacrucclva Taaclng All rupcura dlaca takan off of vinyl reactors auac ba burac In cha maintenance shop whan takan out of aarvlca permanently. Tha follow ing procaduraa also apply co new rupcura dlaca which ara co ba burac whan ehay arrive ac cha Plane. 1. When removing cha holder assembly from cha reactor and when transporting cha holder assembly to the maintenance shop, uaa caution so aa not to damage cha dlac or the holder. ABD00230700 Rupture Dlsc/Rellef Valve Practices Manual Paga 10 CONFIDENTIAL1' ___ _____ _______ ._/ IV. RUPTURE DISC REMOVAL - Continued B. Destructive Testing - continued 2. Whan dastrucclvaly testing a vinyl reactor rupture disc, a qualified maintenance installation observer must be present to observe the testing. 3. Install the holder assembly on the teat bench and pressurize the dlse with air until the disc bursts. 4. If a rupture disc bursts prematurely (less than 90X of Its rated burst pressure) the disc must be given to Process Engineering. Use care so as not to damage these discs. V. RECORDKEEPING A record must be kept of all rupture disc Installation and teatlng data. An example logsheet Is attached. This Information must be stored In the plant for a period of at least two years. VI. TRAINING All maintenance and engineering personnel involved in this program are to receive hands-on training In the Installation and handling of rupture discs once each calendar year. Records of all personnel who attend these training sessions are to be kept for a period of at least tvo years. VII. RELIEF VALVES All relief valves In vinyl chloride service will be periodically checked to ensure that they will operate properly In an emergency situation ABD00230701 Rupur Disc/Relief Valve Practices Manual Page H VII. RELICT VALVES - Continued A. Reactor Relief Valves The past practlca of Canting tha relieving ptasaura of raactor rallaf valvaa In plaea can no longar ba used due co cha change In che getting of the blowdown ring. Vlth che new settings, the quantity of nitrogen available to test the relief valvaa only results In "slauerlng" rather than "popping" of tha valves. Thus a true relieving pressure cannot be determined with the relief valves In place on the reactors. Current practice Is to remove the relief valves from the reactors and to send them to a relief valve repair shop for testing, in spection and reworking. The rework Includes disassembly, cleaning and replacing/refurbishing internal parts as required so that the relief valve meets the original manufacturers specifications. Initially, all reactor relief valves will be sent to a relief valve repair shop on a scheduled basis. The valves will be disassembled, cleaned and refurbished as necessary. The set pressure on each of che relief valves will also be Increased approximately 10 psl while at the repair shop. After the Initial testing and refurbishing, the valves will be re installed on the reactors. The information obtained on valve con dition versus period of time between the rework will be analysed. From this data, a decision on the frequency of testing and refur bishing the valves will be established. ABD00230702 A Rupture Disc/Relief Valve Pracclcea Manual Page 12 comim i] VII. PW.ICT VALVM - Continued A. Reactor Relief Valvee - continued All new reactor relief valvee purchased will be pretested by the aanufacturer. Upon Installation, the relief valves will be re moved and tasted at a relief valve shop per the frequency estab lished above. B. Other Relief Valves in Vinyl Chloride Service Relief valves in the vinyl chloride service, except those on the reactors, will be tested and refurbished at either a relief valve repair shop or by the plant maintenance personnel. The frequency of testing and refurbishing will be established by the plant maintenance department. C. Recordkeeping The maintenance department shall keep a record of all tests and repairs made on the relief valves. ENG Dlsc/9-83/rah ABD00230703 1 j gfs H s|* 6Is0 l|' I-----it V* 0-2 7 FI Bii i i i_ 1 | 1 RUPIURE DISC OVX-TH AJl n a tu re discs In *1 :-*-rviet. ag 3m si | | i L ABD00230704 REACTOR RUPTURE DISC Disc R--d Data Reaoved Specific Location Lot No. Burst Prassura at 70F Burst Prassura at Higher Tcap. Disc Slsa Destructive last Burst Prassura Holder No. indlvldual(s) Removing Disc Indlvldual(s) Performing Dastrucciva Tast Raason for Removal Disc Installad Data Installed Specific Location -ot No. Rated Burst Pressure at 70F Rated Burst Pressure at Higher Taaparatura Disc Slsa Tested to 90F By Tast Observad By Installad on Reactor By Inatallatlon on Reactor Observed By Holder No. Stock No * CONFIDENTIAL ABD00230705 TABLE I RUPTURE DISCS IN VCM SERVICE AVAILABLE AT THE PLANT * S'5&Es-'