PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

101-521Diaphragm,seal Pump

Ontic Engineering & Manufacturing, Inc Dba Ontic Us · NSN 4320-01-042-9733 · FSC 4320 · No Item Name Available
Verified by PartsTable
NSN 4320-01-042-9733 — this item is cataloged by the U.S. Government under National Stock Number 4320-01-042-9733. Primary manufacturer part number: 101-521.
Features
  • Diaphragm,seal Pump — FSC 4320
  • 3 verified cross-references
  • Primary manufacturer: Ontic Engineering & Manufacturing, Inc Dba Ontic Us
Applications
  • Fluid transfer and circulation
  • Cooling system maintenance
  • Industrial process pumping
  • Fluid containment and leak prevention
  • Pressure boundary maintenance
General Description

The Diaphragm,seal Pump, cataloged under National Stock Number 4320-01-042-9733, is classified within Federal Supply Class 4320 (No Item Name Available) of the Pumps and Compressors group. The primary manufacturer of record is Ontic Engineering & Manufacturing, Inc Dba Ontic Us. This item has 3 commercial cross-references from 3 manufacturers, enabling identification through both NSN and commercial part number lookups. 4 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4320-01-042-9733
Primary Part Number101-521
Item NameDiaphragm,seal Pump
FSC / FSG4320 / 43 — No Item Name Available
ManufacturerOntic Engineering & Manufacturing, Inc Dba Ontic Us
StatusACTIVE
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 4
6320-00-312-7348 INTERCHANGEABLE
Indicator,ship's Order
3020-00-431-9256118289 INTERCHANGEABLE
Gear,spur
Kearfott Corporation Div Guidance and Navigation Division
5935-00-438-9561CJ80-9 INTERCHANGEABLE
Connector,plug,electrical
Trompeter Electronics, Inc.
5998-01-254-8390 INTERCHANGEABLE
Circuit Card Assembly
Cross-Reference Index
Part NumberManufacturer
101-521 PRIMARY Ontic Engineering & Manufacturing, Inc Dba Ontic Us (USA)
101-521 Donallco Inc (USA)
101-521 Hamilton Sundstrand Corporation (USA)
Related Parts
6320-00-312-7348INTERCHANGEABLE
INDICATOR,SHIP'S ORDER
3020-00-431-9256INTERCHANGEABLE
GEAR,SPUR
118289
5935-00-438-9561INTERCHANGEABLE
CONNECTOR,PLUG,ELECTRICAL
CJ80-9
5998-01-254-8390INTERCHANGEABLE
CIRCUIT CARD ASSEMBLY

Frequently Asked Questions

What is NSN 4320-01-042-9733?

NSN 4320-01-042-9733 is a Diaphragm,seal Pump, manufactured by Ontic Engineering & Manufacturing, Inc Dba Ontic Us, classified under FSC 4320 (No Item Name Available). Status: active.

What are the part numbers for NSN 4320-01-042-9733?

NSN 4320-01-042-9733 has 3 cross-referenced part numbers: 101-521 (Ontic Engineering & Manufacturing, Inc Dba Ontic Us), 101-521 (Donallco Inc), 101-521 (Hamilton Sundstrand Corporation).

What NSN replaces 4320-01-042-9733?

There are 4 known substitutes for 4320-01-042-9733: 6320-00-312-7348, 3020-00-431-9256, 5935-00-438-9561 and 1 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 101-521?

Key specifications for 101-521: End Item Identification: 4320-00-702-0269YQ PUMP. 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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