Harris · Electronic Components
H421
VALVE,RESTRICTOR CHECK — NSN 4820-00-173-7379
Part NumberH421
ManufacturerHarris
AvailabilityAvailable to order — request a quote
Specifications
NSN4820-00-173-7379 (NSN)
Federal Item NameVALVE,RESTRICTOR CHECK
MaterialSTEEL CORROSION RESISTING OVERALL
Nominal Thread Size0.750 INCHES FIRST END; 0.562 INCHES SECOND END
Connection TypeTHREADED EXTERNAL TUBE FIRST END; THREADED EXTERNAL TUBE SECOND END
Seat Angle12.0 DEGREES FIRST END; 12.0 DEGREES SECOND END
Thread Class3A SECOND END; 3A FIRST END
Operating Pressure3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE
Surface TreatmentPASSIVATE
Thread Series DesignatorUNF SECOND END; UNF FIRST END
Flow Control DevicePOPPET
Connection StyleFLARELESS SECOND END; FLARELESS FIRST END
Federal Supply Class4820 — Valves, Nonpowered
RH Electronics, Inc. — independent stocking distributor since 1982.
Every shipment inspected on receipt · ISO 9001:2015 · ANSI/ESD S20.20 · ERAI member since 1998 · GIDEP participant
Every shipment inspected on receipt · ISO 9001:2015 · ANSI/ESD S20.20 · ERAI member since 1998 · GIDEP participant
Frequently asked
Is H421 available?
We can source H421 even if it isn't in our active stock list. As an independent distributor we reach inventory outside the franchise channel — including hard-to-find and obsolete parts. Send us a quote request.
Is H421 by Harris obsolete or end-of-life?
We specialize in obsolete, end-of-life, and discontinued components. If H421 has been discontinued, we can often source remaining stock or qualified alternates. Contact us with your quantity and target date.
How does RH Electronics verify parts like H421?
Every incoming shipment is inspected under our ISO 9001:2015 quality system — documentation, markings, and construction checked against known-good references. For deeper analysis, we direct work through accredited independent labs. We've been an ERAI member since 1998 and a GIDEP participant.
Can you find a cross-reference or alternate for H421?
Yes. Our team reads part numbers the way they were designed — decoding family, speed, temperature grade, package, and reliability level — to identify acceptable alternates when the exact part isn't available. Submit a quote request and we'll advise.