Valve selection is critical for safe fluid system design and maintenance. The industry-standard STAMPED methodology provides a systematic framework for optimal valve specification across seven parameters:

S - Size: Valve dimension directly determines flow capacity via the **flow coefficient (Cv)** – measuring US gallons per minute at 1 psi pressure drop (60°F). Example: A ½" ball valve typically achieves Cv 7.5 with minimal flow restriction, while an identically sized needle valve may deliver only Cv 2.1 due to its restrictive design. Size selection must align with required flow rates and permissible pressure drop.

T - Temperature: Material performance depends entirely on **temperature rating** boundaries. Both media temperature and operating environment affect integrity: high temperatures degrade material strength (reducing pressure ratings), while thermal cycling accelerates wear. Verify all wetted materials withstand your operating range.

A - Application: Match valve type to primary function:

- Rapid flow isolation → Ball/plug valves  

- Unidirectional flow → Check valves  

- Precision flow control → Needle/bellows valves  

- Overpressure protection → Relief/safety valves  

Correct application matching prevents premature failure.

M - Media Compatibility: Substance properties dictate material selection:

- Inert gases require standard metallurgy  

- Corrosive media demand corrosion-resistant alloys  

- Hazardous fluids necessitate metal seals/diaphragms  

Always validate chemical compatibility against industry charts to prevent stress corrosion cracking.

P - Pressure: Analyze three critical aspects:

1. Maximum system pressure (worst-case scenario)  

2. Operating pressure (standard conditions)  

3. Pressure differential (ΔP) (upstream-downstream difference)  

Higher pressures/ΔP require robust materials and accelerate component wear. Note pressure-temperature interdependence.

E - End Connections: Compatibility with existing infrastructure is non-negotiable. Ensure leak-tight integration through:

- Matching thread standards (NPT, BSPP)  

- Compliant flange ratings (ASME, DIN)  

- Correct tube fitting types (compression, weld)  

Connection mismatches cause systemic integrity failures.

D - Delivery: Evaluate supply chain capability:  

- Technical specification compliance  

- Documentation accuracy  

- Lead time reliability  

- Engineering support capacity  

Supplier performance directly impacts system uptime and safety.