1900 Standard Series - Allied Valve Inc

Scope of Design1900 Series OverviewType 1900 Series1900 Series Conventional Safety Relief ValvesConventionalSteel, Flat Seat, Top Guided, High Capacity, Stainless SteelTrimThis standard rugged configuration is equipped with corrosionresistant trim and a carbon steel body, bonnet and cap. Thecomponents are top guided, providing for free and repeatableaction.The flat disc seat provides for easy maintenance and remachining.The exclusive “Eductor Tube” minimizes bonnet cavity pressureso that product performance is predictable.The nozzle is bottom inserted and rigidly held in position,Vent Plugproviding a corrosion resistant path of flow to the valve andcorrosion resistant seating surfaces.Type 1900-30 Series1900-30 Series Bellows ConstructionBellowsThis valve is the same as the conventional design except that abellows has been added. When the bellows is installed, theeductor tube is removed.Caution: It is important that the bonnet be vented to theatmosphere.A bellows is added to the conventional valve to deal with any ofseveral situations:(1) Back pressure entering the valve through the valve outlet isexcessive or variable. If back pressure fluctuates with ±10%of a nominal value, a bellows is required.Vent,Do Not PlugIf a built up back pressure exceeds 10% of the set pressure orcold differential set pressure, a bellows must be used.(2) If the entering fluid is a slurry, highly viscous, or of a naturethat it can enter the critical clearances between the guides/disc holder, protect that area with a bellows.(3) If the fluid being handled is corrosive to the upper works ofthe valve, isolate the bonnet chamber through use of abellows.Conventional valves can be easily converted to a bellows designor vice versa through the use of retrofit kits.All Consolidated 1900-30 Series valves are balanced bellowsdesigns, meaning that they fully compensate for the effects ofback pressure.1900.4 | Dresser Consolidated ®