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Watts
Plumbing

Model # 1788 Official Watts 1/2" water pressure reducing valve

Here are the diagrams and repair parts for Official Watts 1788 1/2" water pressure reducing valve, as well as links to manuals and error code tables, if available.

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Not all parts are shown on the diagrams—those parts are labeled NI, for “not illustrated”.

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Error Codes

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ALL PARTS
Showing 10 of 45 parts  |
Plate 135B66-M2
#9B

Replacement parts diagram

Plate

Part #135B66-M2

The manufacturer no longer makes this part, and there's no substitute part

Union Nut 35B140
#21B

Replacement parts diagram

Union nut

Part #35B140

The manufacturer no longer makes this part, and there's no substitute part

Lock Washer 174C46
#8

Replacement parts diagram

Lock washer

Part #174C46

The manufacturer no longer makes this part, and there's no substitute part

Disc Holder 50B47
#15A

Replacement parts diagram

Disc holder

Part #50B47

The manufacturer no longer makes this part, and there's no substitute part

Strainer 4500A77
#20B

Replacement parts diagram

Strainer

Part #4500A77

The manufacturer no longer makes this part, and there's no substitute part

Stem & Seal SA-50B27
#11A

Replacement parts diagram

Stem & seal

Part #SA-50B27

The manufacturer no longer makes this part, and there's no substitute part

Spring 124
#5A

Replacement parts diagram

Spring

Part #124

The manufacturer no longer makes this part, and there's no substitute part

Union Tailpc 135C139
#23C

Replacement parts diagram

Union tailpc

Part #135C139

The manufacturer no longer makes this part, and there's no substitute part

Strain Plug 18Y2
#19A

Replacement parts diagram

Strain plug

Part #18Y2

The manufacturer no longer makes this part, and there's no substitute part

Service Kit 5B

#NI

All parts diagram

Service kit

Part #5B

The manufacturer no longer makes this part, and there's no substitute part

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