BS&B SAFETY SYSTEMS, L.L.C. BS&B SAFETY SYSTEMS, LTD. The .

77-4001, Section DRev. 1BS&B SAFETY SYSTEMS, L.L.C.BS&B SAFETY SYSTEMS, LTD.The Sta-Saf System Reverse Buckling TechnologyVisit our websites at www.bsbsystems.com and www.bsb.ie for the most complete, up-to-date information.

StandardFeatures of theSta-Saf Family Sta-Saf Rupture Disks: 90% or greater operating ratio Vacuum resistant Solid metal construction enablingoptimum leak tightness The Sta-Saf SystemThe Sta-Saf system combines six Rupture Disktypes and three safety head options that provide theuser with extended service life reverse buckling disktechnology in sizes from 1"/25mm to 36"/900mmat burst pressures ranging from 5 psi/0.34 bar to2000 psi/137.9 bar.This catalog describes the types JRSTM, S-90TM,RLSTM, and FRSTM Rupture Disks and their SafetyHead (holder) options. The most extensive size andset pressure capability is offered through thesewidely applied designs that are in service in wellover 50,000 installations worldwide. Designed for non-fragmentation Recommended for isolation of pressure reliefvalves Metal tag with product identification andtraceability data, as well as code symbol stampsas appropriateSTA-SAF Safety Heads: Disk dome shielded by safety head inlet for allsizes Locating pins ensure centering and correctorientation of the disk within the safety head “Bite-type” seal for sizes 2”/50mm and largerto optimize leak tightness when appropriatelyinstalled Flow arrow to indicate direction of flow afterinstallation Optional tell-tale connection in safety headoutlet Spiral groove with 125-250 AARH finish onboth inlet and outlet safety head external matingsurfaces to enhance gasket performance2The most capable Sta-Saf technologies, SKRTM &SigmaTM Rupture Disks, have their own dedicatedcatalogs (77-4003 and 77-4011 respectively).Sigma EXL Rupture Disk

Sta-Saf Rupture Disk Material OptionsStandard materials and their maximum recommended service temperatures for the Sta-Saf range ofRupture Disks are:MaterialNickel (alloy 200)MaximumRecommendedTemperatureDisk TypesS-90, RLS, JRS, FRS, SKR, Sigma750 F399 C482 CMonel (alloy 400)S-90, RLS, JRS, FRS, SKR, Sigma900 FInconel (alloy 600)S-90, RLS, JRS, FRS, SKR, Sigma1100 F 593 CStainless SteelS-90, RLS, JRS, FRS, SKR, Sigma750 FHastelloy C-276 (alloy C-276)S-90, RLS, JRS, SKR, Sigma900 F482 CTantalumRLS, SKR500 F260 CTitaniumSKR572 F300 C250 F120 C500 F260 CAluminumS-90Fluoropolymer Film Liners (TEF) S-90, RLS, JRS, FRS, SKR, Sigma400 CFor each material the upper temperature limit hasbeen determined from the recommendations ofmaterial manufacturers and user experience. Rupturedisk technology uses Nickel and its alloys to providethe user with a range of excellent corrosion resistance, and thermal stability particularly in the case ofalloy 600.Hastelloy is a trademark of Haynes InternationalInc., Monel and Inconel are trademarks of Inco AlloysInternational, Inc. BS&B may use equivalent materialsfrom other sources.Fluoropolymer film liners are available as an additional corrosion barrier with most Sta-Saf Rupture Disks.Order as "TEF LINER" when required. Liners areapplied to the inlet/process side of the Rupture Disk,unless otherwise agreed.Teflon materials are typically used (for example FEP,PFA, PTFE).Teflon is an E.I. duPont de Nemours and CompanyCorporation trademark.This wide material range provides the user withoptions in the selection of a Rupture Disk material thatis resistant to the process media. Corrosion of diskmaterial will affect performance and may result in premature burst or leakage through the disk.RLS Rupture DiskJRS Rupture DiskS-90 Rupture DiskOperating Pressure RatioSta-Saf reverse buckling RuptureDisks can be operated to 90% oftheir marked burst pressure (or to95% of their minimum burstpressure) for burst pressures of 40psi (2.76 bar) and higher.For lower burst pressures, theoperating pressure ratio is 90% ofminimum burst pressure. Forapplications that demand a closerrelationship between operatingpressure and burst pressure, selecttype Sigma EXL TM (see catalog77-4011) which can operate up to100% of minimum burst pressure.Differential PressureRupture disks respond to differential pressure. Please take intoaccount the service conditions atthe inlet and outlet of a RuptureDisk when completing specifications.3

Burst Pressure TolerancesAll of the Sta-Saf Rupture Disks offer the same tolerance considerations when completing a specification. Whether the ASME/North American orEuropean/ISO approach to burst pressure and tolerance is used, BS&B applies both a burst tolerance andan optional manufacturing design range.Burst tolerance is the /- range of pressure overwhich a Rupture Disk can be expected to burst. Bursttolerance is either /-5% of burst pressure or /2 psi ( /-0.138 bar) for disks rated below 40 psi(2.76 bar).Manufacturing design range is a range of pressure, always applied to the minus side of the userrequested burst pressure for Sta-Saf Rupture Disks,that simplifies disk fabrication testing and provideseconomic benefit to the user where such an addedtolerance can be accommodated by the application.Manufacturing Design Range (MDR) choices areprovided for all Sta-Saf Rupture Disks:MDR 0: where the user requires the tightest marginbetween normal service pressure and burst pressure, azero range disk shall be used.MDR -5%: applied to the requested burst pressure,a -5% range allows an additional 5% toleranceapplied on the minus side of the user requested burstpressure.MDR -10%: applied to the requested burst pressure, a -10% range allows an additional 10% toleranceapplied on the minus side of the user requested burstpressure.Note: MDR and burst tolerance are additive. In theEuropean/ISO case, the burst tolerance and MDR aresimply combined. In the ASME case, the 'markedburst pressure' for a lot of Rupture Disks must be avalue within the agreed manufacturing design rangeand then the burst tolerance is applied.The two-step approach to set pressurespecification:1. Decide between ASME/North American(with or without 'UD' stamp) and European(with or without 'CE' mark) / ISO standards.2. Select the manufacturing design rangeappropriate to the application and check that itis available for the disk type selected.(0, -5 or -10%)Pressure/Temperature RelationshipThe burst pressure of all Rupture Disks is partiallydetermined by the physical properties of the materialemployed. Tensile strength varies with temperature,which leads to variation in burst pressure. Reversebuckling technology is the least sensitive to temperaturevariations and is used by all Sta-Saf Rupture Disks.However, for the highest accuracy of performance,BS&B certifies Sta-Saf Rupture Disks by testing at theusers’ chosen burst temperature.Where operating pressure and temperature may riserapidly, the user should carefully select the temperatureof the Rupture Disk. BS&B can provide advice for suchapplications. Inconel (alloy 600) provides excellentthermal stability for applications that experience a wideS-90 Rupture Diskrange of service temperatures at which over-pressuremight occur.The burst pressure of each lot of Sta-Saf Rupture Disks is tested at the users specified temperature (burst temperature). Should the disk be rated above or below ambient temperature, burst testing for product certification shallbe conducted at this coincident burst temperature to ensure the best product accuracy. For applications which haveoperating temperatures that may exceed the burst temperature, please review with BS&B Safety Systems, L.L.C. orBS&B Safety Systems, Ltd.4

KR: Flow Resistance FactorDouble Disk AssembliesFlow resistance factor "KR" may be usedto determine the relieving capacity of asystem when using techniques such asthose described in Crane Technical PaperNo. 410.Individual KR values have been established for both gas & liquid service,where appropriate, for Sta-Saf RuptureDisks. Care must be taken to use thecorrect value for sizing purposes.When KR values are marked on Sta-SafRupture Disk tags, those for gas serviceare shown as KRg or KR (GAS), and thosefor liquid service are shown as KRl or KR(LIQ). When using KR value for sizingcalculations, the nominal pipe size(assuming schedule 40 pipe) of the ventsystem is used. When using 'coefficient ofdischarge' sizing techniques, theMinimum Net Flow Area (MNFA) orNet Relief Area (NRA) of the RuptureDisk device is used.The S-90 Rupture Disk manufacturedfrom Inconel (alloy 600) material has thelowest available "KRg" value of 0.232. KR.You can obtain MNFA and NRA valuesat our website at www.bsbsystems.com orfrom our sales representatives and distributors.Double disk assemblies consist of three flange components, aninlet, a mid-flange and an outlet flange with a second disk betweenthe mid-flange and outlet flange. The SRB-7RS Safety Head and theS90-7R Safety Head are availOutlet Flangeable as double disk assemblies.Applications:1. Prevention of leakage ofSecond Diskcorrosive, toxic or expensiveprocess materials and diskservice life extension incontinuous processes. The firstdisk isolates and protects thesecond disk from a corrosiveMid Flangeprocess medium. Leakagecaused by fatigue or corrosionthrough the first disk will beprevented from escaping by theFirst Disksecond disk. Maintenancereplacement can be through aplanned shutdown. (Use of atell-tale assembly between thetwo Rupture Disks is required.)Inlet Flange2. Elimination of back pressure- the second Rupture Disk withstands the system back pressure, isolating the first disk. Any changein pressure differential across the first disk induced by back pressureis eliminated and it will rupture at its rated burst pressure. (Thesecond Rupture Disk may be rated at a lower burst pressure tocompensate for the maximum back pressure that may coincide witha burst condition).3. Quick Opening Valve. The volume between the two disks ispressurized. The evacuation of this pressure causes both disks torupture virtually simultaneously providing an immediate full reliefopening when the inlet pressure exceeds the disk burst pressure.InstallationThe Sta-Saf family of Rupture Diskdevices is designed for installationbetween pipe flanges. Compatibility withall international flange standards is available, including: ANSI, DIN, JIS, BS, ISO,AFNOR and UNI. Between the SafetyHead and the pipe flanges an application compatiblegasket is used for sealing purposes.The unique configuration of the SRB-7RS Safety Headdesign enables the same holder to be installed betweenflanges covering a range of flange specifications. Forexample: a single design of 1"/25mm SRB-7RS SafetyHead is compatible with ANSI 150/300/600, DINPN10/16/25/40, and JIS PN10/16/20/30/40 flanges.This will reduce the inventory of Safety Headsrequired by the user, and provide simplicity of commoninstallation practices.Code ComplianceThe Sta-Saf family of products is designed to meet therequirements of the international Rupture Disk standards.Certification to the following codes is available:ASME Section VIII (including 'UD' stamp) and Section IIICEN ISO 4126 part2 (pending); ‘CE’ MarkISO 6718, BS2915, SVTI, StoomwezenTUV AD Merkblatt A1The Sta-Saf family of Rupture Disk devices is compliantwith API RP520 Part 1 recommendations.5