1. General Introduction
Samson 3251 globe control valve with size 1/2" to 20", pressure rating ANSI Class 150 to 2500, standard material Cast Carbon Steel, Stainless Steel, applicable for temperature range -196 to 550℃, which is mainly for process engineering applications with high industrial requirements.
Once the medium flows through the valve in the direction from entrance, the valve plug determines the cross-sectional area of flow. Bellows seal can be selected for enhancing the leakage function and a flow divider can be equipped for noise reduction. Depending on how the springs are arranged in the pneumatic actuator, there are two fail safe actions available once supply air fails; fail close which actuator stem extends enable to close valve, or fail open which actuator stem retracts enable to open the valve.
2. Technical data for Samson 3251 globe control valve
Material | Cast steel A216 WCC | Cast steel A217 WC6 | Cast stainless steel A351 CF8M |
Valve size and pressure rating | NPS ½ to 12 in Class 150 to 2500 NPS 14 in Class 150 to 600 NPS 16 to 20 in Class 150 to 1500 | ||
Type of connection | Flanges, butted Welding ends | ||
Seat-plug seal | Metal seal, Soft seal, High-performance metal seal | ||
Characteristic | Equal percentage, Linear, Quick opening | ||
Rangeability | 50:1 | ||
Temperature ranges in °C | |||
Body without insulating section | –10 to +220℃ · Up to 350℃ with high-temperature packing | ||
Body with Insulating section or bellows seal | –29 to +425℃ | –29 to +500℃ | –196 to +550℃ |
Valve plug with Metal seal | –196 to +550℃ | ||
Valve plug with Soft seal | –196 to +220℃ | ||
Valve plug balanced with PTFE ring | –50 to +220℃ | ||
Valve plug balanced with graphite ring | 220 to 500℃ | ||
Leakage class according to ANSI/FCI 70‑2 | |||
Valve plug with Metal seal | Standard: IV High-performance metal seal: V | ||
Valve plug with Soft seal | VI | ||
Valve plug with balanced Metal seal | With PTFE ring (standard): IV High-performance metal seal: V With graphite ring: IV | ||
3. Material Table for Samson 3251 globe control valve
Valve body | Cast steel A216 WCC | Cast steel A217 WC6 | Cast stainless steel A351 CF8M |
Valve bonnet | A216 WCC/A 105 | A217 WC6/A 182 F12 Cl.2 | A351 CF8M/A 182 F316 |
Seat and plug with metal seal | 410-2/1.4008 | 316 L/CF3M | |
Seal ring for Soft seal | PTFE with 15 % glass fiber | ||
Seal ring for Pressure balancing | PTFE with carbon · Graphite | ||
Guide bushings | 1.4112 | 2.4610 | |
Packing | V-ring packing: PTFE with carbon, spring: 302 or high-temperature packing | ||
Body gasket | Graphite seal on metal core | ||
Insulating section | A216 WCC/A 105 | A217 WC6/A 182 F12 Cl.2 | A351 CF8M/A 182 F316 |
Metal bellows | 1.4571 | ||
Heating jacket | A240 316L | ||
4. Typical dimension drawings for Samson 3251 globe control valve
