PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

189305EPC30-35Diaphragm,actuator Valve,special

Babcock & Wilcox Companies, the Div Sales & Service · NSN 4820-01-077-9257 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-01-077-9257 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-077-9257. Primary manufacturer part number: 189305EPC30-35.
Features
  • Diaphragm,actuator Valve,special — FSC 4820
  • Criticality Code Justification: ZZZY
  • Reference Number Differentiating Characteristics: MATERIAL WILL BE IN ACCORDANCE WITH NAVICP MECH; ACTIVITY HX QUALITY CONTROL, MANUFACTURING AND TESTING SPECIFICATIONS.
  • 3 verified cross-references
  • Primary manufacturer: Babcock & Wilcox Companies, the Div Sales & Service
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
General Description

The Diaphragm,actuator Valve,special, cataloged under National Stock Number 4820-01-077-9257, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Babcock & Wilcox Companies, the Div Sales & Service. Government technical data includes 2 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 3 manufacturers, enabling identification through both NSN and commercial part number lookups. 1 verified substitute exists in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-01-077-9257
Primary Part Number189305EPC30-35
Item NameDiaphragm,actuator Valve,special
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerBabcock & Wilcox Companies, the Div Sales & Service
StatusACTIVE
Criticality Code JustificationZZZY
Reference Number Differentiating CharacteristicsMATERIAL WILL BE IN ACCORDANCE WITH NAVICP MECH; ACTIVITY HX QUALITY CONTROL, MANUFACTURING AND TESTING SPECIFICATIONS.
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 1
4470-00-297-8568 INTERCHANGEABLE
Diaphragm,manway Seal
Cross-Reference Index
Part NumberManufacturer
189305EPC30-35 Babcock & Wilcox Companies, the Div Sales & Service (USA)
172C9316PC1 Bechtel Technical Services Inc Machinery Apparatus Opn (USA)
495846 PT 275177 Curtiss-Wright Controls, Inc. Div Actuation Division (USA)
Related Parts
4470-00-297-8568INTERCHANGEABLE
DIAPHRAGM,MANWAY SEAL

Frequently Asked Questions

What is NSN 4820-01-077-9257?

NSN 4820-01-077-9257 is a Diaphragm,actuator Valve,special, manufactured by Babcock & Wilcox Companies, the Div Sales & Service, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-01-077-9257?

NSN 4820-01-077-9257 has 3 cross-referenced part numbers: 189305EPC30-35 (Babcock & Wilcox Companies, the Div Sales & Service), 172C9316PC1 (Bechtel Technical Services Inc Machinery Apparatus Opn), 495846 PT 275177 (Curtiss-Wright Controls, Inc. Div Actuation Division).

What NSN replaces 4820-01-077-9257?

There is 1 known substitute for 4820-01-077-9257: 4470-00-297-8568. Verify interchangeability with system specifications before substitution.

What are the specifications of 189305EPC30-35?

Key specifications for 189305EPC30-35: Criticality Code Justification: ZZZY; Reference Number Differentiating Characteristics: MATERIAL WILL BE IN ACCORDANCE WITH NAVICP MECH; ACTIVITY HX QUALITY CONTROL, MANUFACTURING AND TESTING SPECIFICATIONS.. 2 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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