Flexflo 887 Series Surge Reliever Manual | 1
Copyright 2020 Baker Hughes Company. All rights reserved.
Scope
This manual provides instructions for installing, operating,
maitianing and determining the Jacket Pressure Set Point
(JPSP) for all sizes of Flexflo surge relievers.
Product Description
The Flexflo Surge Reliever consists of a slotted metal Core over
which a flexible rubber tube is installed. Tubes each have a
maximum allowable differential pressure rating, based on ASME
Class ratings, and they are molded in a number of different rubber
compounds to meet different applications. The Core has two sets
of openings or slots arranged around the outer circumference of
the Core. The inlet slots are separated from the outlet slots by a
metal barrier. The volume enclosed by the Body sleeve and the
outside surface of the Liner is a pressure chamber known as the
Jacket space. A ported metal Liner is located around the Tube
and prevents over expansion of the Tube. The volume between
the tube and the Liner is known as the Annular volume. The
Jacket and the Annular volume are connected by the ports in the
Liner, and together make up the Total Volume, which is charged
with compressed, dry gas (not with liquid).
Principles of Operation
(Refer to Figure 1 to identify parts).
When the inlet pipeline pressure (upstream of the Surge
Reliever) plus the added pressure required to over come
the Tube material’s natural resistance to expand (the Tube’s
Minimum Differential pressure or DF Minimum) exceeds the
Jacket Pressure Set Point of the Flexflo Surge Reliever, the
Flexflo will start to open and start to relieve the line pressure
upstream of the Flexflo Surge Reliever.
Table Of Contents
Product Description ..................................................................................................................1
Surge Reliever Markings...........................................................................................................1
Principles of Operation .............................................................................................................1
Installation ..................................................................................................................................2
Set Jacket Pressure Set Point ..................................................................................................4
Tube Differential Pressure ........................................................................................................5
Field Assembly and Disassembly ............................................................................................6
Product Support ........................................................................................................................10
Field Disassembly and Reassembly Tables ............................................................................11
Flow
Liner
Tube
Annular
Volume
Jacket Volume
Short Length
is Down-
stream End
Body Sleeve
Jacket at Loading Port
Surge Reliever Markings
Figure 1 - Partial Cutaway of Flexflo Surge Reliever
When the pressure at the inlet of the exceeds the Jacket
Pressure Set Point pressure by the Tube’s DF Minimum
pressure, the valve will start to open. Fluid at the inlet will be
directed up through the upstream slots in the Core, between
the inner surface of the Tube and around the outside surface
of the Core’s Barrier, down into the downstream slots into the
downstream surge line. Minor surges may be absorbed by just
the action of the Tube expanding slightly relieving line pressure
without releasing fluid from the upstream pipeline. Reaction time
for the Surge Reliever is very rapid, in the range of milliseconds.
The additional volume of compressible gas in the Jacket space
allows rapid expansion of the Tube.
Note: Temperature variations will cause the Jacket pressure
to vary. See temperature changes Page 2.
