| 1 | Define the Service Duty | A flanged globe valve uses a valve body with integral or bolted flanges for connection to a piping system. Its internal seat and disc are arranged to regulate or stop flow. | When the handwheel or actuator moves the stem, the disc travels toward or away from the seat. Partial disc movement changes the flow passage and allows throttling. | - Fluid type and chemical compatibility
- Normal, minimum, and maximum flow rate
- Operating temperature and pressure
- Required shutoff and control function
| Benefit: Suitable for reliable isolation and flow regulation.
Limitation: It is generally not the lowest-resistance choice for fully open flow. |
| 2 | Select the Correct Flow Direction | Globe valves commonly use a body passage that changes direction around the seat. Standard, angle, and Y-pattern bodies are available for different piping layouts and pressure-drop requirements. | Flow direction affects the pressure acting on the disc. Correct installation helps reduce unstable disc movement, seat damage, and excessive operating force. | - Check the flow-direction arrow on the valve body
- Confirm whether the valve is intended for flow over or under the disc
- Consider horizontal or vertical pipe orientation
- Review drainability and access for maintenance
| Benefit: Correct direction can improve control stability and service life.
Limitation: Incorrect orientation may increase torque and wear. |
| 3 | Match Pressure and Temperature Ratings | The pressure boundary includes the body, bonnet, stem, disc, seat, gasket, and bolting. Flange dimensions and pressure classes must be compatible with the piping system. | Internal pressure loads the body and closure components, while temperature changes affect material strength, gasket performance, and thermal expansion. | - Required nominal size and flange standard
- Rated pressure at the actual operating temperature
- Body, trim, gasket, and bolting materials
- Design pressure, design temperature, and test requirements
| Benefit: Proper rating supports pressure-boundary integrity.
Limitation: The allowable pressure may decrease as temperature rises. |
| 4 | Choose Materials for the Medium | Common body materials include carbon steel, stainless steel, and other engineered alloys. Internal trim materials may differ from the body to address wear, corrosion, or erosion. | The disc and seat repeatedly contact each other during operation. Material compatibility helps maintain sealing performance and limits corrosion, galling, and erosion. | - Fluid corrosiveness, toxicity, and cleanliness
- Presence of solids, particles, or droplets
- Chlorides, oxygen, hydrogen, or other reactive constituents
- Potential for galvanic corrosion between dissimilar metals
| Benefit: Correct material selection improves durability and leakage resistance.
Limitation: Higher-alloy materials can increase cost and procurement time. |
| 5 | Check the Required Flow Capacity | Globe valves have a defined flow path and a movable disc. Their capacity is commonly evaluated using a flow coefficient such as Cv or an equivalent coefficient specified by the project. | Pressure loss results from changes in flow direction and restriction around the disc and seat. Throttling positions create greater resistance than the fully open position. | - Required flow rate and allowable pressure drop
- Fluid density, viscosity, and vapor pressure
- Expected valve opening during normal operation
- Risk of cavitation, flashing, noise, or vibration
| Benefit: Good sizing provides stable and controllable flow.
Limitation: Oversizing can reduce control resolution; undersizing can cause excessive velocity and pressure loss. |
| 6 | Select the Appropriate Actuation Method | A globe valve may be operated by a handwheel, gearbox, pneumatic actuator, electric actuator, or hydraulic actuator. The stem may use a rising-stem arrangement that shows valve position visually. | The actuator applies linear force or thrust to move the stem and disc. The required force depends on differential pressure, seat load, packing friction, and operating temperature. | - Manual or automated operation requirement
- Required closing time and control accuracy
- Available power or instrument-air supply
- Fail-open, fail-closed, or fail-in-place requirement
- Maximum allowable stem thrust and torque
| Benefit: Actuation can support remote control and process automation.
Limitation: Actuators require correct sizing, commissioning, and maintenance. |
| 7 | Verify Flange, Sealing, and Maintenance Details | Flanged ends use bolts and a gasket to join the valve to matching pipe flanges. The bonnet, packing system, seat, and disc must also be accessible and suitable for the maintenance plan. | The flange gasket provides static sealing at the pipe connection, while stem packing limits leakage around the moving stem. The disc-to-seat interface provides internal shutoff. | - Flange facing, dimensions, drilling, and bolt compatibility
- Gasket type, material, thickness, and surface condition
- Face-to-face dimension and installation clearance
- Seat leakage requirement and applicable inspection standard
- Availability of replacement packing and internal parts
| Benefit: Correct connection details reduce installation and leakage problems.
Limitation: Flanged valves need more space and more installation work than some compact end connections. |
