1900 Series - Maintenance Manual

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VI. Handling, Storage, and Pre-InstallationHandlingStorageAlways keep the inlet flang down on a crated or uncratedflang valve to prevent misalignment and damageto valve internals.ATTENTION!!Never lift the full weight of the valve by thelifting lever.ATTENTION!!Do not rotate the valve horizontally or lift/carryusing the lifting lever.Store SRVs in a dry environment and protect them fromthe weather. Do not remove the valve from the skids orcrates until immediately before installation.Do not remove flang protectors and seating plugs untilthe valve is ready to be bolted into place during theinstallation.Pre-InstallationWhen SRVs are uncrated and the flang protectors orsealing plugs are removed, exercise meticulous care toprevent dirt and other foreign materials from entering theinlet and outlet ports while bolting the valve in place.vWrap a chain or sling around the discharge neck andaround the upper bonnet structure to move or hoist anuncrated valve. Ensure the valve is in a vertical positionduring the lift.ATTENTION!!Handle carefully. Do not drop or strike the valve.Do not subject SRVs, either crated or uncrated, to sharpimpact. Ensure that the valve is not bumped or droppedduring loading or unloading from a truck. While hoistingthe valve, take care to prevent bumping the valveagainst steel structures and other objects.ATTENTION!!Prevent dust and debris from entering inlet or outletof the valve.14 | Dresser Consolidated ®
VII. Recommended Installation PracticesMounting PositionMount safety relief valvesin a vertical, uprightposition only.Do not mount valve atthe end of pipe throughwhich there is normally noflow or near elbows, tees,bends, etc.Mount SRVs in a vertical (upright) position (in accordance with API RP 520). Installinga safety relief valve in any position other than vertical (±1 degree) will adverselyaffect its operation as a result of the induced misalignment of moving parts.A stop valve may be placed between the pressure vessel and its relief valve only aspermitted by code regulations. If a stop valve is located between the pressure vesseland SRV, the stop valve port area should equal or exceed the nominal internal areaassociated with the pipe size of the SRV inlet. The pressure drop from the vessel tothe SRV shall not exceed 3% of the valve’s set pressure, when flowin at full capacity.Ensure the flange and sealing faces of the valve and connective piping are freefrom dirt, sediment, and scale.Ensure all flang bolts are drawn evenly to prevent distortion of the valve body andthe inlet nozzle.Position SRVs for easy access and/or removal so that servicing can be properlyperformed. Ensure sufficien working space is provided around and above the valve.Inlet PipingThe inlet piping (see Figure 11) to the valve should be short and directly from thevessel or equipment being protected. The radius of the connection to the vesselshould permit smooth flo to the valve. Avoid sharp corners. If this is not practical,then the inlet should be at least one additional pipe diameter larger.The pressure drop from the vessel to the valve shall not exceed 3% of valve setpressure when the valve is allowing full capacity flo. The inlet piping should neverbe smaller in diameter than the inlet connection of the valve. Excessive pressuredrop in gas, vapor, or flashing-liqui service at the inlet of the SRV will cause theextremely rapid opening and closing of the valve, which is known as “chattering.”Chattering will result in lowered capacity and damage to the seating surfaces. Themost desirable installation is that in which the nominal size of the inlet piping is thesame as, or greater than, the nominal size of the valve inlet flange and in whichthe length does not exceed the face-to-face dimensions of a standard tee of therequired pressure class.Do not locate SRV inlets where excessive turbulence is present, such as nearelbows, tees, bends, orifice plates or throttling valves.Section VIII of the ASME Boiler and Pressure Vessel Code requires the inletconnection design to consider stress conditions during valve operation, caused byexternal loading, vibration, and loads due to thermal expansion of the dischargepiping.The determination of reaction forces during valve discharge is the responsibility ofthe vessel and/or piping designer. Dresser publishes certain technical informationabout reaction forces under various flui flo conditions, but assumes no liability forthe calculations and design of the inlet piping.Heed all servicemanual warnings. Readinstallation instructionsbefore installing valve(s).External loading, by poorly designed discharge piping and support systems, andforced alignment of discharge piping can cause excessive stresses and distortionsin the valve as well as the inlet piping. The stresses in the valve may cause amalfunction or leak. Therefore, discharge piping must be independently supportedand carefully aligned.Vibrations in the inlet piping systems may cause valve seat leakage and/or fatigue<strong>1900</strong> <strong>Series</strong> Safety Valve (July/2010) | 15
Page 4 and 5: Table of ContentsSection Subject Pa
Page 6 and 7: I. Product Safety Sign and Label Sy
Page 8 and 9: III. IntroductionThe safety relief
Page 10 and 11: V. (Contd.)V.1.1 Standard Cap Types
Page 12 and 13: V. (Contd.)V.3 V-W Bellows Metal Se
Page 16 and 17: VII. Recommended Installation Pract
Page 18: VIII. Disassembly Instructions (Con
Page 21 and 22: X. Parts InspectionNozzle Inspectio
Page 23 and 24: X. Parts Inspection (Contd.)Orifice
Page 25 and 26: X. Parts Inspection (Contd.)AFigure
Page 27 and 28: X. Parts Inspection (Contd.)Orifice
Page 29 and 30: X. Parts Inspection (Contd.)Guide I
Page 31 and 32: XI. MaintenanceGeneral InformationA
Page 33 and 34: XI. Maintenance (Contd.)Table 7d: N
Page 35 and 36: XI. Maintenance (Contd.)Re-Machinin
Page 37 and 38: XI. Maintenance (Contd.)OrificeSize
Page 39 and 40: XII. ReassemblyGeneral InformationT
Page 41 and 42: XII. Reassembly (Contd.) Use a scre
Page 43 and 44: XII. Reassembly (Contd.)OrificeTabl
Page 45 and 46: XIII. Setting and TestingGeneral In
Page 47 and 48: XIII. Setting and Testing (Contd.)S
Page 49 and 50: XIII. Setting and Testing (Contd.)I
Page 51 and 52: XVI. Conversion of 1900 Series Flan
Page 53 and 54: XVII. Troubleshooting 1900 Series S
Page 55 and 56: XIX. Replacement Parts PlanningBasi
Page 57 and 58: XXI. Recommended Spare Parts for 19
Page 59 and 60: XXI. Manufacturer’s Warranty, Fie
Page 61 and 62: XXV. Optional Glide-Aloy PartsOptio
Page 63 and 64: XXVI. Sales Office LocationsMALAYSI

1900 Series - Maintenance Manual

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