The Ins-and-Outs of Remanufactured Fisher® 95 Series Regulators

Remanufactured Fisher® 95 series regulators are direct-operated, downstream pressure-regulating devices for gasses, vapors, and clean, non-viscous fluids. Learn more in this video with Keith Angle, a process control engineer at Automation Service.

Their principle of operation is simply balancing the forces between the downstream pressure and the main spring. The fluid fills the area under the diaphragm and creates an upward force that counteracts the downward spring force.

Before the regulator is pressurized, the valve plug is held open by the main spring. As downstream pressure increases under the diaphragm, it lifts the diaphragm and compresses the main spring. This allows the plug to travel toward the orifice, restricting and ultimately shutting off the flow.
When demand increases, the pressure under the diaphragm is reduced and that allows the main spring to extend. It moves the plug away from the orifice, allowing flow. As the pressure increases, it lifts the main spring and restricts flow.

The 95 series are available with cast iron, carbon steel and stainless steel bodies designed with threaded or flanged process connections. There are basically two types of trim sets, a soft seat or a metal seat.

The metal seat provides a Class IV shutoff and the soft seat offers a tighter Class VI shutoff. The diaphragm material is typically the same as the plug.

For steam and other hotter services, the diaphragm and plug are typically SST.

For other fluids, like carbon dioxide or air, neoprene diaphragms and seats are preferred.

There are various body sizes and spring ranges available as well. If you have any questions or would like assistance with specifying a remanufactured regulator, give us a call at 800-325-4808. We’re here to help!