1900 Series - Maintenance Manual

III. IntroductionThe safety relief valve (SRV) is an automatic, pressureactuatedrelieving device suitable for use either as asafety valve or relief valve, depending on application.SRVs are used on hundreds of different applications,including liquids and hydrocarbons; therefore, the valveis designed to meet many requirements.The 1900 Series valves included in this manual maybe used to meet the requirements for ASME Section IIIand Section VIII. They cannot be used on ASME CodeSection I steam boilers or superheaters, but may beused on process steam.IV. Design Features andNomenclatureCap and Lever InterchangeabilityIn the field, it is often necessary to change the type ofcap or lever after a valve has been installed. All flangedConsolidated ® SRVs are designed to be converted toany type of lever or cap desired. It is not necessary toremove the SRV from the installation, nor will the setpressure be affected when making such a change.Design SimplicityConsolidated ® SRVs have few component parts,resulting in savings by minimizing spare parts inventoryand simplifying valve maintenance.Nomenclature Related to Design FeaturesThe nomenclature of the components of 1900 Seriesvalves, including those with design options for universalmedia, universal media soft-seat bellows, O-ring seat,liquid trim, and Thermodisc ® , is identified in Figures 1through 10.Simple Blowdown AdjustmentThe Consolidated ® single blowdown ring design makesit possible to set and test a valve at the customer’sshop when it is impractical to set and media may bevery low, the ring can be positioned so that the setpoint can be observed without damaging the valve.Blowdown can be attained by positioning the ring inaccordance with the adjusting ring position (see Tables12 through 14).Valve InterchangeabilityA standard Consolidated ® SRV may be converted tothe universal media, universal media soft-seat bellowstype, the O-ring seat seal type, etc., and vice versa.Should conversion be required, this interchangeabilitylowers costs and requires fewer new parts thanreplacing entire valve types.8 | Dresser Consolidated ®