The 1900-30-UM Series valve includes the addition of a balanced bellows that is necessary to compensate for the effects of variable back pressure. By isolating the upper structure and allowing the use of less expensive materials, the bellows is also a costeffective solution in applications where the valve is exposed to highly viscous or corrosive fluids.
1900-UM-DA Series Soft Seat
The 1900-UM-DA Series soft seat contains an additional soft seal. This soft seat is the primary seal, and it allows the valve to remain leak free at 95 percent of set pressure over 100 psig (6.89 barg). A backup metal seat provides additional safety for firerelief applications when soft goods can be destroyed by high temperature exposure. The Consolidated 1900-UM Series soft seat is available for set pressures up to 6250 psig (430.92 barg). Some soft seats offered by other manufacturers are limited to 1500 psig (103,42 barg).