PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

77321003Valve,safety Relief

Emerson Automation Solutions Final Control Us Lp Div Navy Product Team · NSN 4820-01-434-6660 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-434-6660 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-434-6660. Primary manufacturer part number: 77321003.
Features
  • Valve,safety Relief — FSC 4820
  • Flow Control Device: DISK
  • Raised Face Nominal Diameter: 2.000 INCHES FIRST END IN
  • Disk Loading Method: SPRING
  • Valve Operation Method: AUTOMATIC
  • Flange Shape: ROUND WITH HOLES ALL ENDS
  • Nominal Outside Diameter: 0.500 INCHES SECOND END IN
  • Bolt Hole Nominal Diameter: 0.625 INCHES ALL ENDS IN
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Rubber Seat construction
General Description

The Valve,safety Relief, cataloged under National Stock Number 4820-01-434-6660, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Emerson Automation Solutions Final Control Us Lp Div Navy Product Team. Government technical data includes 29 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 4 commercial cross-references from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 9 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-01-434-6660
Primary Part Number77321003
Item NameValve,safety Relief
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerEmerson Automation Solutions Final Control Us Lp Div Navy Product Team
StatusACTIVE
Flow Control DeviceDISK
Raised Face Nominal Diameter2.000 INCHES FIRST END IN
Disk Loading MethodSPRING
Valve Operation MethodAUTOMATIC
Flange ShapeROUND WITH HOLES ALL ENDS
Nominal Outside Diameter0.500 INCHES SECOND END IN
Bolt Hole Nominal Diameter0.625 INCHES ALL ENDS IN
MaterialRUBBER SEAT
Second Connection Face to Centerline Distance4.250 INCHES IN
Nominal Thickness0.562 INCHES FIRST END IN
First Connection Face to Centerline Distance4.000 INCHES IN
Connection TypeFLANGE ALL ENDS
Bolt Circle Nominal Diameter2.375 INCHES SECOND END IN
Valve Size1.000 INCHES IN
MaterialSTEEL COMP 316 FLOW CONTROL DEVICE
Raised Face Nominal Diameter1.375 INCHES SECOND END IN
Maximum Operating Temp500.0 FAHRENHEIT SINGLE RESPONSE DEGF
Nominal Thickness0.438 INCHES SECOND END IN
Adjustable Pressure Range+56.0 TO 77.0 POUNDS PER SQUARE INCH LBS
MaterialSTEEL COMP 416 STEM
Bolt Hole Quantity4 ALL ENDS
Nominal Outside Diameter1.000 INCHES FIRST END IN
Media for Which DesignedFUEL/OIL, HYDROCARBON SINGLE RESPONSE
Style DesignatorANGLE FLANGED ENDS
Valve Discharge Flow Rate18.0 GALLONS PER MINUTE
Operating Pressure1500.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Raised Face Nominal Height0.062 INCHES ALL ENDS IN
Bolt Circle Nominal Diameter3.125 INCHES FIRST END IN
MaterialSTEEL COMP 316 BODY
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 9
4820-01-434-5344122598 INTERCHANGEABLE
Disk,valve
Emerson Automation Solutions Final Control Us Lp Div Navy Product Team
4820-01-434-5345122584 INTERCHANGEABLE
Guide,valve Stem
Emerson Automation Solutions Final Control Us Lp Div Navy Product Team
4820-01-434-5348122599 INTERCHANGEABLE
Retainer,disk,valve
Emerson Automation Solutions Final Control Us Lp Div Navy Product Team
4820-01-434-5488123760 INTERCHANGEABLE
Stem,fluid Valve
Emerson Automation Solutions Final Control Us Lp Div Navy Product Team
4820-01-434-6129S75376 INTERCHANGEABLE
Base Assembly,relief Valve
Emerson Automation Solutions Final Control Us Lp Div Navy Product Team
4820-01-434-6632121555 INTERCHANGEABLE
Disk,valve
Emerson Automation Solutions Final Control Us Lp Div Navy Product Team
4820-01-434-6636121393 INTERCHANGEABLE
Guide,valve Stem
Emerson Automation Solutions Final Control Us Lp Div Navy Product Team
4820-01-434-7948123365 INTERCHANGEABLE
Stem,fluid Valve
Emerson Automation Solutions Final Control Us Lp Div Navy Product Team
4820-01-434-7968121556 INTERCHANGEABLE
Retainer,disk,valve
Emerson Automation Solutions Final Control Us Lp Div Navy Product Team
Cross-Reference Index
Part NumberManufacturer
77321003 PRIMARY Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA)
DS-G-74893 ASSY 77321003 Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA)
DS-G-74893 Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA)
9512101D0050 0100 56T77PSI Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA)
Related Parts
4820-01-434-5344INTERCHANGEABLE
DISK,VALVE
122598
4820-01-434-5345INTERCHANGEABLE
GUIDE,VALVE STEM
122584
4820-01-434-5348INTERCHANGEABLE
RETAINER,DISK,VALVE
122599
4820-01-434-5488INTERCHANGEABLE
STEM,FLUID VALVE
123760
4820-01-434-6129INTERCHANGEABLE
BASE ASSEMBLY,RELIEF VALVE
S75376
4820-01-434-6632INTERCHANGEABLE
DISK,VALVE
121555
4820-01-434-6636INTERCHANGEABLE
GUIDE,VALVE STEM
121393
4820-01-434-7948INTERCHANGEABLE
STEM,FLUID VALVE
123365
4820-01-434-7968INTERCHANGEABLE
RETAINER,DISK,VALVE
121556

Frequently Asked Questions

What is NSN 4820-01-434-6660?

NSN 4820-01-434-6660 is a Valve,safety Relief, manufactured by Emerson Automation Solutions Final Control Us Lp Div Navy Product Team, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-434-6660?

NSN 4820-01-434-6660 has 4 cross-referenced part numbers: 77321003 (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team), DS-G-74893 ASSY 77321003 (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team), DS-G-74893 (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team), 9512101D0050 0100 56T77PSI (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team).

What NSN replaces 4820-01-434-6660?

There are 9 known substitutes for 4820-01-434-6660: 4820-01-434-5344, 4820-01-434-5345, 4820-01-434-5348 and 6 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 77321003?

Key specifications for 77321003: Flow Control Device: DISK; Raised Face Nominal Diameter: 2.000 INCHES FIRST END IN; Disk Loading Method: SPRING; Valve Operation Method: AUTOMATIC. 30 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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