1900 Standard Series - Allied Valve Inc

Pressure / TemperaturePressure / Temperature TablesHow To Use Rating TablesThe included tables specify important data about the valveincluding valve sizes, flange ratings, pressure and temperaturelimits, back pressure ratings, and materials with allowabletemperature ranges.After determining valve size from the Valve Sizing section,or capacity tables in this section, select the proper set oftables and graphs (in the following pages) for the size valve.Enter the pressure/temperature graphs and determine valvetype. Review the table of data for that size valve to get otherpertinent information.ProcedureExampleValve Set Pressure500 psig (34.47 barg)Back Pressure50 psig (3.45 barg)Temperature100°F (37.8°C)Valve“J”Enter the graph on page 1900.71 for the “J” size, select setpressure on the bottom scale at 500 psig (34.47 barg), followthis line vertically upward until it intersects the 100°F (38°C)line. The selection is a 1910Jc valve.ResultsNotes:1. The pressure/temperature limitations shown in the followingtables are based on the limits specified in API526 applicableto the 1900 series supplied in standard materials ofconstruction. For pressure/temperature limitations of valvesmade from special materials, consult the factory or the SRVSsizing program. (Note that 1900-30 bellows design valvesupplied with the standard Inconel 625 bellows is limited to atemperature range of 400°F (204°C) to 1500°F (816°C).)2. ASME Class 300 outlet flanges are permitted for matingpurposes only on valves that are normally supplied withstandard ASME Class 150 pressure rating. For back pressureapplications exceeding the ASME Class 150 pressure ratinguse SRVS sizing program or contact the factory forassistance.3. When soft seats are used, they may govern the valvepressure/temperature rating.Referring to the table on page 1900.70, the valve is 3” (76.2mm) - 300 x 4” (101.6 mm) - 150 with a carbon steel body andspring. The back pressure limit is satisfactory for 50 psig (3.45barg) back pressure.SpringsWithin given temperature limits, alloy steel springs arespecified. Because of material availability from vendors, mostsprings are of alloy steel construction which provides superiorstrength and corrosion resistant properties.MaterialsThe operating temperature should be used to select thematerials in valves for fire sizing applications.Minimum Set PressuresThe minimum set pressures of the 1900 flanged valves are inaccordance with the following table.OrificeLow Set Pressure Limit 2Conventional Valve Bellows Valve 1psig barg psig bargD 5 0.34 15 1.03E 5 0.34 15 1.03F 5 0.34 15 1.03G 4 0.27 15 1.03H 4 0.27 15 1.03J 5 0.34 10 0.68K 5 0.34 10 0.68L 6 0.41 10 0.68M 6 0.41 10 0.68Notes:1 The bonnet must be vented whena bellows is used.2 Valves with set pressure less than15 psig cannot be stamped withthe ASME stamp.1900 Series Safety Relief Valve | 1900.61