PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

500-HP-18-MTest Stand,compressed Gas Cylind

Hydro-Test Products, Inc. Dba Hydro-Test Products Inc · NSN 6635-00-334-7421 · FSC 6635 · No Item Name Available
Verified by PartsTable
NSN 6635-00-334-7421 — this item is cataloged by the U.S. Government under National Stock Number 6635-00-334-7421. Primary manufacturer part number: 500-HP-18-M.
Features
  • Test Stand,compressed Gas Cylind — FSC 6635
  • Drive Type: SINGLE HEAD
  • Maximum Generator Diameter Accommodated: 18.000 INCHES IN
  • Driving Motor Transmission: NOT INCLUDED
  • Mounting Type: FLOOR
  • 7 verified cross-references
  • Primary manufacturer: Hydro-Test Products, Inc. Dba Hydro-Test Products Inc
Applications
  • Industrial maintenance and repair
  • Government and military logistics
  • Equipment overhaul and refurbishment
General Description

The Test Stand,compressed Gas Cylind, cataloged under National Stock Number 6635-00-334-7421, is classified within Federal Supply Class 6635 (No Item Name Available) of the Instruments and Laboratory Equipment group. The primary manufacturer of record is Hydro-Test Products, Inc. Dba Hydro-Test Products Inc. Government technical data includes 4 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 7 commercial cross-references from 5 manufacturers, enabling identification through both NSN and commercial part number lookups. 7 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN6635-00-334-7421
Primary Part Number500-HP-18-M
Item NameTest Stand,compressed Gas Cylind
FSC / FSG6635 / 66 — No Item Name Available
ManufacturerHydro-Test Products, Inc. Dba Hydro-Test Products Inc
StatusCANCELLED
Drive TypeSINGLE HEAD
Maximum Generator Diameter Accommodated18.000 INCHES IN
Driving Motor TransmissionNOT INCLUDED
Mounting TypeFLOOR
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 7
5999-00-025-637974068 INTERCHANGEABLE
Connector-Switch
L-3 Communications Westwood Corporation Dba Nmp Division Div L3 Westwood Corporation
5360-00-072-6734120472 INTERCHANGEABLE
Spring,helical,extension
Michael Reese Research Foundation
3110-00-100-060055437 INTERCHANGEABLE
Cup,tapered Roller Bearing
The Timken Corporation
6635-00-181-2458 INTERCHANGEABLE
Test Stand,compressed Gas Cylind
5133-00-228-135314750 INTERCHANGEABLE
Drill,twist
Viking Drill & Tool, Inc.
5325-00-436-140374068 INTERCHANGEABLE
Ring,retaining
Textron Lycoming Inc Williamsport Plant
4730-01-239-248574068 INTERCHANGEABLE
Tee,tube
Werfen Usa Llc
Cross-Reference Index
Part NumberManufacturer
500-HP-18-M PRIMARY Hydro-Test Products, Inc. Dba Hydro-Test Products Inc (USA)
107-323 Cryogenic Equipment Inc (USA)
6635-2830-5000 Defense Supply Center Richmond Industrial Plant Equipment /dla/ (USA)
74068 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
MILS4068 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
500-520 PRIMARY Hydro-Test Products, Inc. Dba Hydro-Test Products Inc (USA)
107-323 Kidde-Fenwal, Llc (USA)
Related Parts
5999-00-025-6379INTERCHANGEABLE
CONNECTOR-SWITCH
74068
5360-00-072-6734INTERCHANGEABLE
SPRING,HELICAL,EXTENSION
120472
3110-00-100-0600INTERCHANGEABLE
CUP,TAPERED ROLLER BEARING
55437
6635-00-181-2458INTERCHANGEABLE
TEST STAND,COMPRESSED GAS CYLIND
5133-00-228-1353INTERCHANGEABLE
DRILL,TWIST
14750
5325-00-436-1403INTERCHANGEABLE
RING,RETAINING
74068
4730-01-239-2485INTERCHANGEABLE
TEE,TUBE
74068

Frequently Asked Questions

What is NSN 6635-00-334-7421?

NSN 6635-00-334-7421 is a Test Stand,compressed Gas Cylind, manufactured by Hydro-Test Products, Inc. Dba Hydro-Test Products Inc, classified under FSC 6635 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 6635-00-334-7421?

NSN 6635-00-334-7421 has 7 cross-referenced part numbers: 500-HP-18-M (Hydro-Test Products, Inc. Dba Hydro-Test Products Inc), 107-323 (Cryogenic Equipment Inc), 6635-2830-5000 (Defense Supply Center Richmond Industrial Plant Equipment /dla/), 74068 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), MILS4068 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M) and 2 more.

What NSN replaces 6635-00-334-7421?

There are 7 known substitutes for 6635-00-334-7421: 5999-00-025-6379, 5360-00-072-6734, 3110-00-100-0600 and 4 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 500-HP-18-M?

Key specifications for 500-HP-18-M: Drive Type: SINGLE HEAD; Special Features: 8000 PSI TEST CAPACITY; AIR OPERATED TEST PUMP; SOFT SEATED INLET/OUTLET CHECK VALVES; 8 AND ONE-HALF IN. DIA. CALIBRATED TEST GAGE; 8000 PSI CALIBRATED TEST CYLINDER; 18 IN. DIA. BY 72IN. TALL WATER JACKET; 6 INDIVIDUALLY VALVED MANIFOLDED BURETTES,SIZES: 0-12.5 CC, 0-25 CC, 0-50 CC,0-125 CC,0- 250 CC,0-360 CC; D JACKET,PRESSURIZED INTERNALLY TO SPECIFIEDTEST PRESSURE V OLUMETRIC EXPANSION MEAS URED VIA WATER DISPLACED INTO CALIBRATED BURETTE. ELASTIC EXPANSIONS CALCULATED FROM MEASURED TOTAL AND PERMANENT VOLUMETRIC IN; Maximum Generator Diameter Accommodated: 18.000 INCHES IN; Driving Motor Transmission: NOT INCLUDED. 5 total characteristics are documented in the Federal Logistics Information System.

Is NSN 6635-00-334-7421 still in active supply?

NSN 6635-00-334-7421 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

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