Relief Valve, Part No. D41P-30UU, NSN 4820-01-249-9964: Global Buyer's Guide to Diaphragm & Relief Valve Parts
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Relief Valve, Part No. D41P-30UU, NSN 4820-01-249-9964 is a pressure/flow control component in the diaphragm-and-relief-valve family, used to relieve excess pressure and regulate water or fluid flow in flushometer valves and similar assemblies. Buyers should confirm the OEM part number, the NSN, and the host valve series before ordering.
What is a relief valve, and what does NSN 4820-01-249-9964 identify?
A relief valve is a safety and control device that opens to relieve excess pressure or to regulate flow within a system, protecting downstream components and maintaining consistent operation. In commercial plumbing and fluid handling, relief valve parts work alongside diaphragms inside flushometer valves to control the flush cycle.
The NSN (National Stock Number) 4820-01-249-9964 is a 13-digit logistics identifier used across government, defense, and industrial supply chains to specify a unique valve component. The 4820 federal supply class covers valves and valve assemblies, so an NSN search is often the fastest way to confirm you are ordering the correct interchangeable part.
Part No. D41P-30UU is the manufacturer part number associated with this relief valve. When sourcing, always cross-check the MPN against the NSN and the host equipment to avoid a mismatch. Brands such as SLOAN and AMTC VALVE are common in this category, and 3G Electric supplies diaphragm and relief valve parts across multiple OEM lines.
How does a diaphragm and relief valve assembly work?
Inside a flushometer valve, a diaphragm separates the upper and lower chambers. When the handle or sensor is actuated, the relief valve lifts, equalizing pressure and allowing water to flow through the diaphragm assembly for the flush cycle.
When the cycle completes, the relief valve reseats and the diaphragm returns to its closed position, stopping flow. A worn diaphragm or a sticking relief valve is the most common cause of a running or weak flush, which is why these parts are replaced together.
This same pressure-relief principle applies beyond plumbing: relief valves protect pumps, compressors, and process lines by venting excess pressure before it damages seals, gauges, or downstream equipment.
Spec table: relief valve and diaphragm part attributes
| Attribute | Value / Range | Notes |
|---|---|---|
| Manufacturer part number | D41P-30UU | Verify against host valve |
| NSN | 4820-01-249-9964 | Federal supply class 4820 (valves) |
| Component type | Relief valve / diaphragm assembly part | Used in flushometer and fluid systems |
| Flush rating (compatible assemblies) | 1.28 gpf to 3.5 gpf | Match to host fixture rating |
| Typical supply voltage (sensor valves) | 6 VDC to 24 VDC | Confirm at point of use |
| AC supply context | 50 Hz / 60 Hz | State frequency for export builds |
| Currency for quoting | USD | Export documentation available |
Which relief valve type suits your application?
Relief valve and diaphragm parts fall into a few practical families. Choosing the right one depends on the host equipment, the media, and the duty cycle.
- Flushometer diaphragm and relief valve assemblies — for commercial toilets and urinals; matched to gpf ratings such as 1.28 gpf or 3.5 gpf.
- Guide assemblies — control the relief valve travel inside G2-series and similar flush valves.
- Pressure relief valves for fluid/pump systems — protect pumps and process lines from overpressure.
- Sprayer and finishing-system relief/repair parts — restore function in industrial painting equipment.
In Worldwide markets, the same valve body may be supplied with different voltage or frequency options for sensor-operated models, so always confirm the electrical variant alongside the mechanical part number.
Selection criteria: how to choose the right relief valve part
- Confirm the MPN and NSN. Match D41P-30UU and NSN 4820-01-249-9964 exactly, then verify the host valve series.
- Match the flush or pressure rating. Use the fixture's gpf rating (e.g. 1.28 gpf, 3.5 gpf) or the system's pressure setpoint.
- Check the media and environment. Water quality, temperature, and chemical exposure affect diaphragm and seal life.
- Confirm the electrical variant. For sensor valves, verify 6–24 VDC and whether the site runs 50 Hz or 60 Hz AC supply.
- Assess duty cycle. High-traffic commercial restrooms need more frequent inspection and replacement intervals.
- Plan for spares. Multi-packs reduce downtime on large sites with many identical valves.
Product comparison: compatible diaphragm and relief valve parts
The table below compares representative diaphragm and relief valve parts available from 3G Electric, arranged from single-fixture repair parts to multi-pack maintenance kits.
| Product | Type | Rating / Spec | Best for |
|---|---|---|---|
| SLOAN Diaphragm Assembly for Regal Series Urinal Flush Valves | Diaphragm assembly (includes disc) | Regal® series urinal valves | Single urinal repair |
| SLOAN Diaphragm Assembly for Royal Series 1.28 gpf Toilets | Diaphragm + relief valve components | 1.28 gpf | High-efficiency toilet repair |
| SLOAN Guide Assembly for G2 Series Flush Valves, 6-Pack | Guide assembly (relief valve control) | 3.5 gpf, 6-pack | Multi-unit maintenance |
| 3M Spray Gun Rebuild Kit for Paint Sprayers | Composite repair kit | Exterior replacement parts | Finishing-system restoration |
| 3M Spray Gun Pressure Whip, 7 1/4 in | Composite pressure whip | 7 1/4 in length | Pump-to-gun fluid delivery |
Step up the ladder when you are maintaining multiple fixtures: a single diaphragm assembly suits one repair, while a 6-pack guide assembly is more economical for facilities with many identical valves. For finishing systems, move from individual parts to a full rebuild kit when several components are worn.
Why source relief valve parts from 3G Electric?
3G Electric stocks 130+ products across related categories and brings 35+ years of experience interpreting customer demand and delivering genuine industrial equipment, parts, and supplies. We supply across 14 industrial departments — machining, electrical, power transmission, material handling, plumbing, HVAC & refrigeration, pneumatics, hydraulics, pumps, instrumentation, test & measurement, welding, lighting, and combustion/burner systems — and we supply far more than is listed.
Our specialist depth in combustion, pumps, and controls means we can help you verify a part number, confirm a cross-reference, and get the right answer rather than simply filling an order. We ship worldwide with export documentation experience and incoterms-neutral supply, quoting in USD.
Frequently asked questions
How do I confirm Relief Valve Part No. D41P-30UU is the right part?
Match the manufacturer part number D41P-30UU and NSN 4820-01-249-9964 against your host valve's documentation, then confirm the valve series and flush or pressure rating. If the cross-reference is unclear, contact 3G Electric for verification before ordering.
What does NSN 4820-01-249-9964 mean?
It is a 13-digit National Stock Number in federal supply class 4820, which covers valves and valve assemblies. The NSN uniquely identifies the relief valve component for government, defense, and industrial procurement, and is used alongside the manufacturer part number.
Where can I buy relief valve and diaphragm parts in Worldwide?
3G Electric supplies diaphragm and relief valve parts worldwide, including SLOAN-compatible assemblies and 3M finishing-system parts. We quote in USD, handle export documentation, and support international delivery — contact us for current availability and lead times.
What is the difference between a diaphragm assembly and a relief valve?
A diaphragm assembly is the flexible membrane that separates chambers and controls flow in a flushometer valve. The relief valve is the smaller component that lifts to equalize pressure and initiate the flush. They are often replaced together because both wear at similar rates.
Do sensor-operated relief valves need 50 Hz or 60 Hz supply?
Sensor flush valves typically run on low-voltage DC (commonly 6–24 VDC), so mains frequency matters mainly for the power supply or adapter. For export builds, confirm whether the site uses 50 Hz or 60 Hz AC and specify the matching supply variant.
How long does worldwide delivery take?
Lead time depends on stock status and destination. In-stock items ship quickly with export documentation prepared for international delivery; special-order or cross-referenced parts may take longer. Contact 3G Electric for a specific lead-time estimate for your location.
Key takeaways
- Relief Valve Part No. D41P-30UU, NSN 4820-01-249-9964 is a diaphragm/relief valve component for flushometer and fluid systems — always verify MPN and NSN together.
- Match the flush rating (1.28 gpf to 3.5 gpf) or pressure setpoint to your host equipment.
- For sensor valves, confirm the DC voltage (6–24 VDC) and whether the site runs 50 Hz or 60 Hz AC.
- Multi-pack guide and diaphragm assemblies reduce downtime on high-traffic sites.
- 3G Electric supplies worldwide with 35+ years of experience, USD quoting, and export documentation support.
Ready to order or need sizing help? Contact 3G Electric for quotes, cross-reference verification, and technical support on Relief Valve Part No. D41P-30UU, NSN 4820-01-249-9964 and compatible diaphragm and relief valve parts.
