Fisher Manuals & Guides: Fisher SS-264 Thrust Washer/ Semi-Finished Blank vs. Finished Machine (IM Supplement) Manuals & Guides

Instruction Manual Supplement

D104190X012

SS-264 Thrust Washer

October 2017

Fisher™ SS-264 Thrust Washer;
Semi-Finished Blank vs. Finished Machined

Overview

The SS-264 valve body assembly contains a thrust washer (PN GE50801Xxxx) that is machined-to-fit from a blank
semi-finished part (PN GE48568Xxxx), for each unique valve assembly. If the semi-finished blank is installed during the
valve assembly process, internal surfaces and parts may be irreversibly damaged. These instructions cover how to
store the blank part and subsequently machine the finished part from the blank. For all other information regarding
the SS-264 rotary control valve refer to the SS-264 instruction manual (D103565X012
your Emerson sales office

These instructions are applicable to both inventories and first-time builds at Fisher facilities as well as spare parts
inventories for replacement/refurbishment at AP1000 customer plant facilities.

or Local Business Partner.

CAUTION

), available at Fisher.com or from

This Instruction Manual Supplement must remain with the blank at all times during storage.

Storage - Thrust Washer Blank

The blank will be stored in a cardboard box with this instruction manual supplement until a finished thrust washer is
needed. The blank can be identified by the words ‘THRUST WASHER BLANK – DO NOT INSTALL IN VALVE UNTIL
MACHINED’ which are laser etched on a surface of the blank. The blank OD and ID are at their final dimensions; only
the thickness needs to be machined.

Procedure to Calculate Thrust Washer Thickness

When a thrust washer is called for in a valve body assembly, certain component part dimensions are needed to be able
to calculate the final machined thickness. This thickness is based on existing dimensions of the body, bonnet, ball and
drive bearing of the unique valve assembly for which it is intended to be installed in. Once the calculation is completed
and a thrust washer is machined to final thickness, it can only be used in that valve assembly, due to its’ unique fit with
existing parts.

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SS-264 Thrust Washer

October 2017

Instruction Manual Supplement

D104190X012

1. Record the piece serial numbers and dimension values BE, AM, C, and G in table 1. See the images on the following
pages for measurement locations. If the parts are new or unworn (original build), the dimensions can be taken from
part inspection documentation taken during part production. However, if the valve is undergoing refurbishment,
the parts may be worn and original inspection values will not be valid. Measure dimensions carefully in the field.

2. Calculate the thrust washer thickness, DIM A, by subtracting AM, C, and G from BE.

3. Record DIM A in table 1, and retain this work instruction with appropriate engineering plant records as evidence the
thrust washer calculation was completed.

4. Machine the thrust washer thickness to DIM A, as calculated in table 1. Thickness tolerance is ± 0.001 inches;
face-to-face parallelism is 0.002 inches; a 32 Ra surface finish on both sides applies.

5. The finished thrust washer is now complete and ready for installation.

Table 1. Calculation to Find Thrust Washer Final Thickness Value

Part Description Part Number Dimension Measured Value Piece Serial Number

Valve Body GE48000XXXX BE
Bonnet GE48043XXXX AM
Drive Bearing GE46775XXXX C
Ball GE46770XXXX G

Dim A = BE-AM-C-G

NOTE

The parts measured as well as the finished thrust washer must remain together until assembled. The thrust washer
thickness is now unique to that particular assembly.

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