PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

26M77-100 ITEM 31Disk Retainer and Throttling Ski

Electric Boat Corporation Div General Dynamics Electric Boat · NSN 4820-01-159-7777 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-159-7777 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-159-7777. Primary manufacturer part number: 26M77-100 ITEM 31.
Features
  • Disk Retainer and Throttling Ski — FSC 4820
  • General Characteristics Item Description: NICKEL COPPER ALLOY,QQ-N-281;SIZE 3.000 IN.;OD 2.778 IN. NOMINAL;HEIGHT 3.250 IN. NOMINAL;ONE HOLE 0.172 IN. DIA,AND 0.531 IN. DEEP,0.812 IN. FROM CENTER IN
  • 4 verified cross-references
  • Primary manufacturer: Electric Boat Corporation Div General Dynamics Electric Boat
Applications
  • Flow control in piping systems
  • Water treatment infrastructure
  • Industrial process control
General Description

The Disk Retainer and Throttling Ski, cataloged under National Stock Number 4820-01-159-7777, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Electric Boat Corporation Div General Dynamics Electric Boat. Government technical data includes 1 verified specification, sourced from the Federal Logistics Information System (FLIS). This item has 4 commercial cross-references from 2 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
NSN4820-01-159-7777
Primary Part Number26M77-100 ITEM 31
Item NameDisk Retainer and Throttling Ski
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerElectric Boat Corporation Div General Dynamics Electric Boat
StatusACTIVE
General Characteristics Item DescriptionNICKEL COPPER ALLOY,QQ-N-281;SIZE 3.000 IN.;OD 2.778 IN. NOMINAL;HEIGHT 3.250 IN. NOMINAL;ONE HOLE 0.172 IN. DIA,AND 0.531 IN. DEEP,0.812 IN. FROM CENTER IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
4820-00-900-234426M77-100 ITEM 19 INTERCHANGEABLE
Disk,valve
Naval Ship Systems Command
4820-01-092-034326M77-100 ITEM 21 INTERCHANGEABLE
Retainer,disk,valve
Naval Ship Systems Command
4820-01-121-29032620-920X12 PIECE 53 3IN INTERCHANGEABLE
Adapter,splined,globe Valve
Hydro-Aire Aerospace Corp
4320-01-148-830526M77-100 ITEM90 INTERCHANGEABLE
Ring,wearing
Electric Boat Corporation Div General Dynamics Electric Boat
4820-01-151-380826M77-100 ITEM 94 INTERCHANGEABLE
Guide,valve Stem
Electric Boat Corporation Div General Dynamics Electric Boat
4820-01-160-160426M77-100 ITEM 93 INTERCHANGEABLE
Guide,valve Stem
Electric Boat Corporation Div General Dynamics Electric Boat
4820-01-161-093226M77-100 PIECE 18 INTERCHANGEABLE
Seat,valve
Electric Boat Corporation Div General Dynamics Electric Boat
4820-01-161-519026M77-100 PIECE 20 INTERCHANGEABLE
Disk,valve
Electric Boat Corporation Div General Dynamics Electric Boat
3020-01-190-616326M77-100 PIECE 55 4IN INTERCHANGEABLE
Gear,bevel
Electric Boat Corporation Div General Dynamics Electric Boat
5340-01-199-808326M77-100 ITEM 70 INTERCHANGEABLE
Plunger,detent
Electric Boat Corporation Div General Dynamics Electric Boat
Cross-Reference Index
Part NumberManufacturer
845-2445066 Naval Ship Systems Command (USA)
26M77-100 Electric Boat Corporation Div General Dynamics Electric Boat (USA)
26M77-100 ITEM 31 PRIMARY Electric Boat Corporation Div General Dynamics Electric Boat (USA)
845-2445066 ITEM 31 PRIMARY Naval Ship Systems Command (USA)
Related Parts
4820-00-900-2344INTERCHANGEABLE
DISK,VALVE
26M77-100 ITEM 19
4820-01-092-0343INTERCHANGEABLE
RETAINER,DISK,VALVE
26M77-100 ITEM 21
4820-01-121-2903INTERCHANGEABLE
ADAPTER,SPLINED,GLOBE VALVE
2620-920X12 PIECE 53 3IN
4320-01-148-8305INTERCHANGEABLE
RING,WEARING
26M77-100 ITEM90
4820-01-151-3808INTERCHANGEABLE
GUIDE,VALVE STEM
26M77-100 ITEM 94
4820-01-160-1604INTERCHANGEABLE
GUIDE,VALVE STEM
26M77-100 ITEM 93
4820-01-161-0932INTERCHANGEABLE
SEAT,VALVE
26M77-100 PIECE 18
4820-01-161-5190INTERCHANGEABLE
DISK,VALVE
26M77-100 PIECE 20
3020-01-190-6163INTERCHANGEABLE
GEAR,BEVEL
26M77-100 PIECE 55 4IN
5340-01-199-8083INTERCHANGEABLE
PLUNGER,DETENT
26M77-100 ITEM 70
3020-01-212-0328INTERCHANGEABLE
GEAR SET,BEVEL,MATCHED
845-2445066 ITEM 55,66
4820-01-216-9271INTERCHANGEABLE
DISK STEM RING,VALV
26N77-100 ITEM 28

Frequently Asked Questions

What is NSN 4820-01-159-7777?

NSN 4820-01-159-7777 is a Disk Retainer and Throttling Ski, manufactured by Electric Boat Corporation Div General Dynamics Electric Boat, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-159-7777?

NSN 4820-01-159-7777 has 4 cross-referenced part numbers: 845-2445066 (Naval Ship Systems Command), 26M77-100 (Electric Boat Corporation Div General Dynamics Electric Boat), 26M77-100 ITEM 31 (Electric Boat Corporation Div General Dynamics Electric Boat), 845-2445066 ITEM 31 (Naval Ship Systems Command).

What NSN replaces 4820-01-159-7777?

There are 12 known substitutes for 4820-01-159-7777: 4820-00-900-2344, 4820-01-092-0343, 4820-01-121-2903 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 26M77-100 ITEM 31?

Key specifications for 26M77-100 ITEM 31: General Characteristics Item Description: NICKEL COPPER ALLOY,QQ-N-281;SIZE 3.000 IN.;OD 2.778 IN. NOMINAL;HEIGHT 3.250 IN. NOMINAL;ONE HOLE 0.172 IN. DIA,AND 0.531 IN. DEEP,0.812 IN. FROM CENTER IN. 1 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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