Accumulator (Optional) - Emerson Bettis EHO Installation And Operation Manual

Installation and Operation Manual
Part Number: VA001-507-32, Rev. 1
2.8

Accumulator (Optional)

2.8.1
The Bettis EHO Actuator may be equipped with an accumulator to enable manual
operation of the actuator if there is a loss of electrical power. Accumulators always
have the nitrogen pressure drained for shipping (except for Thermal Compensating
Accumulator see 2.3.4).
NOTE:
When using this procedure, refer to the Bettis EHO Actuator General Arrangement
drawing and Hydraulic Schematic for the unit being worked on. (Schematic below is for
illustration only.)
WARNING:
This unit contains high-pressure hydraulic fluid and nitrogen gas. Exercise caution when
performing any type of maintenance. Wear proper safety attire and required personal
protective equipment, including safety glasses.
2.8.2
NOTE:
The Adaptor is tapped with a 1/4-NPTF thread.
NOTE:
For temperatures, which do not appear on the graph, the formula to calculate the
pre-charge pressure shown on the General Arrangement Picture Assembly should be
used.
Installation
Introduction
Accumulator Pre-charge
a. Locate Isolation Valve (F) (Nitrogen Blow Down and Fill) for the
Customer Nitrogen Fill Connection, called out on the General
Arrangement Drawing and Hydraulic Schematic (see illustration below).
b. Close the Isolation Valve (F) and remove the pipe plug from the adaptor.
c. Ensure 3-way Isolation Valve (D) is turned fully counterclockwise.
d. Slowly open Isolation Valve (Accumulator drain) (E) and drain all the
fluid back to the reservoir.
e. Connect a nitrogen supply to the Customer Nitrogen Fill Connection at
Isolation Valve (F).
f. Open the Isolation Valve (F) (Nitrogen Blow Down and Fill) and
charge the Accumulator, to the pre-charge pressure as specified by
the Pressure versus Temperature Graph on the General Arrangement
Drawing.
Section 2: Installation
August 2016
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