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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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Model diagram and schematic

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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

Strain Plug 18Y2
#19A

Replacement parts diagram

Strain plug

Part #18Y2

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

Adjustment Nut 30B33
#2

Replacement parts diagram

Adjustment nut

Part #30B33

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

Union Tailpc 135B139
#23B

Replacement parts diagram

Union tailpc

Part #135B139

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

Gasket 1-1/8X1-3/8
#16B

Replacement parts diagram

Gasket

Part #1-1/8X1-3/8

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

Disc Washer 25B60
#13

Replacement parts diagram

Disc washer

Part #25B60

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

Union Nut 35A140
#21A

Replacement parts diagram

Union nut

Part #35A140

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

Union Seal 35C103
#22C

Replacement parts diagram

Union seal

Part #35C103

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

Service Kit 5C

#NI

All parts diagram

Service kit

Part #5C

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

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