Principle Of Operation - Emerson MR95 Series Instruction Manual

MR95 Series - AD2000 Compliant
▲
WARNING
Failure to follow these instructions or
to properly install and maintain this
equipment could result in an explosion,
fire and/or chemical contamination
causing property damage and personal
injury or death.
Fisher™ regulators must be installed,
operated and maintained in accordance
with federal, state and local codes, rules
and regulations and Emerson Process
Management Regulator Technologies,
Inc. (Emerson) instructions.
If the regulator vents gas or a leak
develops in the system, service to
the unit may be required. Failure
to correct trouble could result in a
hazardous condition.
Installation, operation and maintenance
procedures performed by unqualified
personnel may result in improper
adjustment and unsafe operation. Either
condition may result in equipment
damage or personal injury. Only a
qualified person shall install or service
the MR95 Series regulator.
Introduction
Scope of the Manual
This manual provides instructions for the installation,
adjustment, maintenance and parts ordering for
MR95 Series pressure regulators. These regulators
are usually shipped separately for line or panel
mounting or installed on other equipment. Instructions
and parts lists for other equipment are found in
separate manuals.
6
Product Description
The MR95 Series pressure reducing and differential
pressure regulators are suitable for multiple fluid
mediums including liquid, gas, air and steam services.
Typical applications include use in but not limited to
wash tanks, small heaters, fuel and oil lines, air supply
systems, test fixtures and sterilizers.
Types MR95H, MR95HP and MR95HT regulators
are direct-operated pressure reducing regulators for
pressure control requiring constant outlet pressures
between 0.34 and 27.6 bar / 5 to 400 psig.
See Tables 1 through 6 for detailed breakdown of the
various construction offerings. Typical MR95 Series
regulators are shown in Figure 1

Principle of Operation

Types MR95H, MR95HP and MR95HT (see Figure 2)
are direct-operated regulators and use spring force to
regulate outlet pressure.
Downstream pressure is registered either internally
through the body or externally through a control
line to the underside of the diaphragm. When the
downstream pressure is at or above the set pressure,
the disk is held against the orifice and restricting
flow through the regulator. When demand increases,
downstream pressure drops slightly allowing the spring
to extend, moving the stem down and the disk away
from the orifice. This allows fluid flow through the body
to the downstream system.