Product reference / DONGLI

Shear-pin pressure relief valves

Two sizes. Documented from actual samples.

Compare 2″ and 3″ sample photographs and nameplate records.

2-inch 21050, photographed assembly

21050 / DONGLI

2″ Shear-pin relief valve

5,000 psi · nameplate max. WP

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3-inch 30550, photographed assembly

30550 / DONGLI

3″ Shear-pin relief valve

5,000 psi · nameplate max. WP

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Side by side

Compare the records

Recorded item2″ / 210503″ / 30550
Nominal size2″3″
Nameplate part no.2105030550
Nameplate max. working pressure5,000 psi5,000 psi
Nameplate max. temperature250 °F250 °F
Photo-annotated unit weight12.5 kg33 kg

Sizes were supplied by the user. Pressure and temperature are from photographed nameplates; weights are photo annotations and have not been independently measured. Images are fitted individually and are not to a common scale. Confirm connections, threads, shear pins and operating duty separately.

Reference library / original PDF

Original references. Check against the actual valve.

These two OTECO English-language publications were supplied as references for model and component identification. Their materials, certifications, pressure configurations and part conditions do not automatically apply to the DONGLI samples and do not establish brand authorization or interchange.

EB-003 pages 3–4 describe the conditions for nominal relief pressures and specified shear pins. Confirm the actual configuration, duty and controlled technical documents before selection.

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Part atlas

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Callouts

Crankshafts & bearingsrecords 55 Connecting rodsrecords 18 Crossheads, wrist pins & guidesrecords 31 Packing, seals & gasketsrecords 115 Pony & piston rodsrecords 47 Cylinder linersrecords 107 Pistons, cups & plungersrecords 104 Fluid-end modules & chambersrecords 52 Valves, seats & springsrecords 140 Valve & cylinder coversrecords 38 Relief valves & dischargerecords 21

Relief valves & discharge

21 catalogue records2 with a part number6 part types

Reference brands named in records

  • DONGLI2

Identification only; not OEM authorization or fitment.

Browse all Safety / Relief Valve records (5)
Generic schematic of a reciprocating piston pump, drawn for navigation only: not to scale and not taken from any manufacturer’s drawing. Callouts group our catalogue records by their catalogued part type; they do not indicate that any record fits a particular pump. Fitment, specifications and availability are confirmed case by case against the original part number and manual. 728 of 944 catalogue records are grouped on this drawing; the other 216 (general pump parts, kits, tools and similar) are in the full parts directory. Full parts directory

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