PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

6F3256Valve,restrictor Check

Crissair Inc Div Esco Technologies · NSN 4820-01-181-5766 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-181-5766 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-181-5766. Primary manufacturer part number: 6F3256.
Features
  • Valve,restrictor Check — FSC 4820
  • Valve Operation Method: AUTOMATIC
  • Connection Type: THREADED EXTERNAL TUBE ALL ENDS
  • Nominal Thread Size: 0.562 INCHES FIRST END IN
  • Thread Series Designator: UNIFIED NATIONAL JOINT FINE (UNJF) FIRST END
  • Flow Control Device: POPPET
  • Thread Class: 3A FIRST END A
  • Style Designator: STRAIGHT THRU
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Steel Body construction
General Description

The Valve,restrictor Check, cataloged under National Stock Number 4820-01-181-5766, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Crissair Inc Div Esco Technologies. Government technical data includes 10 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 7 commercial cross-references from 3 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-01-181-5766
Primary Part Number6F3256
Item NameValve,restrictor Check
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerCrissair Inc Div Esco Technologies
StatusACTIVE
Valve Operation MethodAUTOMATIC
Connection TypeTHREADED EXTERNAL TUBE ALL ENDS
Nominal Thread Size0.562 INCHES FIRST END IN
Thread Series DesignatorUNIFIED NATIONAL JOINT FINE (UNJF) FIRST END
Flow Control DevicePOPPET
Thread Class3A FIRST END A
Style DesignatorSTRAIGHT THRU
Thread DirectionRIGHT-HAND FIRST END
Disk Loading MethodSPRING
MaterialSTEEL BODY
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
8110-00-030-7780 INTERCHANGEABLE
Drum,shipping and Storage
3110-00-100-61861-2BALLGRADE2 INTERCHANGEABLE
Ball,bearing
Skf Usa Inc.
2520-00-225-1445B3160 INTERCHANGEABLE
Piston,clutch
Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic
5930-00-507-83245590 INTERCHANGEABLE
Switch,toggle
Cole Hersee Company
5355-00-951-052623625-1 INTERCHANGEABLE
Adjuster,meter Pointer
Drs Signal Solutions, Inc.
4820-01-013-14799R3302 INTERCHANGEABLE
Valve,restrictor Check
Crissair Inc Div Esco Technologies
4820-01-114-58455590-147 INTERCHANGEABLE
Valve,restrictor Check
The Boeing Company Div Defense
5307-01-190-3901 INTERCHANGEABLE
Stud
6130-01-253-751228625-1 INTERCHANGEABLE
Inverter,power,static
L3 Technologies, Inc. Div Communication Systems-West
5998-01-378-808208757-60055 INTERCHANGEABLE
Circuit Card Assembly
Aerobase Group Inc
Cross-Reference Index
Part NumberManufacturer
5590-151 The Boeing Company Div Defense (USA)
6F3256 PRIMARY Crissair Inc Div Esco Technologies (USA)
236251 The Boeing Company Div Defense (USA)
5590 The Boeing Company Div Defense (USA)
B3160 PRIMARY Preece Inc Decca Valves Div (USA)
A254615 The Boeing Company Div Defense (USA)
286251 The Boeing Company Div Defense (USA)
Related Parts
8110-00-030-7780INTERCHANGEABLE
DRUM,SHIPPING AND STORAGE
3110-00-100-6186INTERCHANGEABLE
BALL,BEARING
1-2BALLGRADE2
2520-00-225-1445INTERCHANGEABLE
PISTON,CLUTCH
B3160
5930-00-507-8324INTERCHANGEABLE
SWITCH,TOGGLE
5590
5355-00-951-0526INTERCHANGEABLE
ADJUSTER,METER POINTER
23625-1
4820-01-013-1479INTERCHANGEABLE
VALVE,RESTRICTOR CHECK
9R3302
4820-01-114-5845INTERCHANGEABLE
VALVE,RESTRICTOR CHECK
5590-147
5307-01-190-3901INTERCHANGEABLE
STUD
6130-01-253-7512INTERCHANGEABLE
INVERTER,POWER,STATIC
28625-1
5998-01-378-8082INTERCHANGEABLE
CIRCUIT CARD ASSEMBLY
08757-60055
5310-01-478-4756INTERCHANGEABLE
NUT,SELF-LOCKING,HEXAGON
5590
6515-01-507-1861INTERCHANGEABLE
SAW,STERNUM
5590

Frequently Asked Questions

What is NSN 4820-01-181-5766?

NSN 4820-01-181-5766 is a Valve,restrictor Check, manufactured by Crissair Inc Div Esco Technologies, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-181-5766?

NSN 4820-01-181-5766 has 7 cross-referenced part numbers: 5590-151 (The Boeing Company Div Defense), 6F3256 (Crissair Inc Div Esco Technologies), 236251 (The Boeing Company Div Defense), 5590 (The Boeing Company Div Defense), B3160 (Preece Inc Decca Valves Div) and 2 more.

What NSN replaces 4820-01-181-5766?

There are 12 known substitutes for 4820-01-181-5766: 8110-00-030-7780, 3110-00-100-6186, 2520-00-225-1445 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 6F3256?

Key specifications for 6F3256: Valve Operation Method: AUTOMATIC; Connection Type: THREADED EXTERNAL TUBE ALL ENDS; Nominal Thread Size: 0.562 INCHES FIRST END IN; Thread Series Designator: UNIFIED NATIONAL JOINT FINE (UNJF) FIRST END. 10 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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