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2nd
1st
Actuator Type
87 Spring Diaphragm
Air to Close
88 Spring Diaphragm
Air to Open
1. Introduction
The following instructions should be thoroughly reviewed
and understood prior to installing, operating or performing
maintenance on this equipment. Throughout the text, safety
and/or caution notes will appear and must be strictly adhered to,
otherwise, serious injury or equipment malfunction could result.
Baker Hughes has a highly skilled After Sales Department
available for start-up, maintenance and repair of our valves and
component parts.
Arrangements for this service can be made through your local
Baker Hughes's representative or sales department. When
performing maintenance use only Masoneilan
parts. Parts are obtainable through your local representative or
spare parts department. When ordering parts, always include
Model and Serial Number of the unit being repaired.
2. General
These installation and maintenance instructions apply to all sizes
and ratings of the 21000 Series control valves regardless of the
type of trim used.
21000 Series single ported top guided control valves are designed
with built in versatility making them well-suited to handle a wide
variety of process applications.
Standard construction offers a contoured plug (21100 Series)
with a threaded seat ring or a quick change seat ring. The heavy
top plug guiding provides maximum support to ensure plug
stability.
A series of reduced area trim is available to provide wide flow
range capabilities in all valve sizes.
Tight Shutoff Class IV leakage is standard. Optional constructions
(one of which is the 21600 Series soft seat plug) meet IEC 534-4
and ANSI/FCI 70.2 Class V and Vl requirements.
An optional Low Emission LE
compliance with the fugitive emission containment requirements.
Replacing the conventional plug with the single stage Lo-dB
design (21700 Series) provides excellent noise attenuation or
anti-cavitation performance.
2 | Baker Hughes
1st
Body
Plug Type
Series
0. Undefined
21
1. Contoured
6. Soft Seat
7. Single Stage
Lo-dB/
Cavitation
Containment
8. Double Stage
Cavitation
Containment
9. Double Stage
Lo-dB
™
replacement
Packing is available to assure
™
2nd
3rd
4th
Flow
Characteristics
0. Undefined
1. Linear
2. Equal
Percentage
3. Modified
Percent
Figure 1 – Numbering System
The 21800 Series double stage anti-cavitation valve is derived
from the 21700 single stage anti-cavitation valve through a
modification to the cage and plug. Substitution of the standard
cage with an anti-cavitation cage permits the pressure drop to be
split between the two stages efficiently.
The 21900 Series double stage Lo-dB valve is also derived from
the 21700 single stage Lo-dB valve through a modification to
the cage and plug. Substitution of the standard cage, with a Lo-
dB cage permits the pressure drop to be split between the two
stages efficiently.
In the 21800/21900 Series designs, enlargement of the plug
head up to the cage diameter permits simultaneous throttling of
the plug Cv and the cage Cv. It also provides optimum allocation
of the pressure drop between the two stages along the entire
plug travel.
Recommended spare parts required for maintenance are listed
in the Parts Reference table on page 17. The model number,
size, rating and serial number of the valve are shown on the
identification tag located on the actuator. Refer to Figure 1 for the
21000 series numbering system.
3. Unpacking
Care must be exercised when unpacking the valve to prevent
damage to the accessories and component parts. Contact the
local Baker Hughes Sales office or Service Center with any
issues or problems. Be sure to note the valve model number and
serial number in all correspondence.
4. lnstallation
4.1 Piping Cleanliness
Before installing the valve in the line, clean piping and valve of
all foreign material such as welding chips, scale, oil, grease or
dirt. Gasket surfaces should be thoroughly cleaned to ensure
leak-proof joints.
4.2 Isolation Bypass Valve
To allow for in-line inspection, maintenance or removal of the
valve without service interruption, provide a manually operated
Copyright 2023 Baker Hughes Company. All rights reserved.
5th
6th
Optional
Configuration
Seat Type
0. Undefined
A Angle Body
BS Bellows
4. Quick Change
5. Threaded
Seal
EB Extension
Bonnet
C Cryogenic
Extension
Bonnet
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