A cast steel globe valve is a linear-motion valve used for shutoff and flow regulation in industrial piping systems. Unlike a gate valve, a globe valve is designed to control flow by moving its disc toward or away from the seat. This makes it a common choice for applications where throttling, reliable shutoff, and controlled flow are important.
For industrial projects, selecting the right globe valve is not simply a matter of choosing a body material. The valve should be specified according to pressure, temperature, fluid properties, pressure drop, trim requirements, end connection, applicable standards, and inspection requirements.
What Is a Cast Steel Globe Valve?
A cast steel globe valve is a globe valve with a cast steel pressure-containing body and bonnet. The valve uses a movable disc and stationary seat to control the flow of fluid.
When the handwheel or actuator moves the stem upward, the disc lifts away from the seat and opens the flow passage. When the stem moves downward, the disc approaches the seat and restricts or stops flow.
The main components normally include:
- Body
- Bonnet
- Disc
- Stem
- Seat
- Backseat
- Gland and packing
- Handwheel or actuator
- Bolting
- Gasket
For higher-pressure or higher-temperature applications, the construction and material selection become especially important because the body, bonnet, stem, seat and packing all have to remain compatible with the service conditions.
How Does a Cast Steel Globe Valve Work?
A globe valve controls flow through the linear movement of its disc.
The basic operating sequence is straightforward:
Valve open: The disc is lifted away from the seat, allowing fluid to pass.
Throttling: The disc is positioned between fully open and fully closed to regulate flow.
Valve closed: The disc presses against the seat to stop the flow.
The internal flow path of a globe valve creates more pressure drop than a typical full-port gate valve. The trade-off is better control over flow.
This is why globe valves are commonly selected for throttling and regulating duties where the additional pressure loss is acceptable.
cast steel globe valve Technical parameters
| Item | Common options |
|---|---|
| Nominal size | NPS 2 and larger, depending on design |
| Pressure class | Class 150, 300, 600, 900, 1500, 2500 |
| Body materials | WCB, WCC, LCB, WC6, WC9, CF8M and other grades |
| Bonnet | Bolted bonnet or pressure-seal design, depending on applicable specification |
| Body pattern | Z-type, Y-type, angle |
| End connections | RF, RTJ, BW, depending on design and standard |
| Operation | Handwheel, gear, pneumatic, electric or hydraulic actuator |
| Trim | 13Cr, stainless steel, alloy steel, hardfaced and other project-specific options |
Actual size and pressure availability should be confirmed against the valve manufacturer's design and the applicable project specification.
Main external dimensions of cast steel gate valve
|
Size |
DN |
15 |
20 |
25 |
32 |
40 |
50 |
65 |
80 |
100 |
125 |
150 |
200 |
250 |
300 |
350 |
400 |
|
L |
mm |
130 |
150 |
160 |
180 |
200 |
230 |
290 |
310 |
350 |
400 |
480 |
600 |
650 |
750 |
850 |
950 |
|
H |
mm |
200 |
243 |
253 |
280 |
312 |
321 |
325 |
355 |
415 |
460 |
510 |
700 |
975 |
1115 |
1250 |
1380 |
|
W |
mm |
120 |
140 |
160 |
160 |
200 |
200 |
240 |
240 |
280 |
320 |
360 |
560 |
600 |
700 |
800 |
900 |
|
Weight |
kg |
5 |
6.5 |
7 |
13.5 |
16 |
32 |
45 |
60 |
80 |
107 |
134 |
268 |
449 |
663 |
750 |
1170 |
Cast Steel Globe Valve Design
Common globe valve body configurations include:
Z-Type Globe Valve
The Z-type, or standard pattern, is widely used for general industrial service. The flow path changes direction inside the body, which provides good throttling characteristics but also creates a relatively high pressure drop.
Y-Type Globe Valve
A Y-pattern globe valve provides a more streamlined flow path than a standard Z-pattern design. It can reduce pressure loss and is often considered for higher-pressure-drop or more demanding services.
Angle Globe Valve
An angle globe valve changes the flow direction by approximately 90 degrees within the valve body. It can simplify piping layouts and may be useful where the valve is installed at a change in piping direction.
The appropriate body pattern should be selected according to the process conditions, available space, pressure drop, and project specification.
End Connections
Common end configurations include:
RF Flanged Ends
Raised-face flanges are widely used for general industrial piping. The flange dimensions and pressure class should match the applicable piping standard and project requirements.
RTJ Ends
Ring-type joint connections are commonly used in higher-pressure services where the piping specification calls for RTJ sealing.
Butt-Welding Ends
Butt-welding ends provide a welded connection between the valve and piping. They are frequently used in high-pressure and high-temperature process systems.
The end connection should always be specified together with the pressure class and applicable dimensional standard.
Cast Steel Globe Valve Features
- Simple structure: simpler than a gate valve, easier to manufacture and maintain.
- Reliable sealing: the sealing surface is less prone to wear and scratching because there is no relative sliding between the disc and the seat during opening and closing; this gives good sealing performance and a long service life.
- Compact height: the disc stroke is smaller, so the valve height is less than that of a gate valve of the same size, but the structural length is longer.
- Higher torque: opening and closing torque is larger, requiring more effort and a longer actuation time.
- Higher fluid resistance: the tortuous medium passage inside the body creates higher fluid resistance and higher power consumption - the price paid for its precise throttling capability.
- One-way flow: the medium can flow in only one direction and cannot be reversed. When the nominal pressure is up to 16 MPa, co-current flow is generally adopted, with the medium flowing upward from below the disc; when the nominal pressure is 20 MPa or above, counter-current flow is adopted, with the medium flowing downward from above the disc, to increase the sealing performance.
When fully open, the valve disc is frequently eroded.
Cast Steel Globe Valve Applications
- Petrochemical industry: controlling the transport of crude oil, natural gas and chemical products, preventing leaks and accidents.
- Power industry: regulating water and steam flow in boiler feedwater systems and steam pipelines.
- Metallurgical industry: handling high-temperature or corrosive media while ensuring pipeline safety.
- Water treatment: controlling fluid flow in urban water supply and sewage treatment.
Quality Inspection and Testing
For B2B valve procurement, testing and documentation are just as important as the valve body material.
Depending on the purchase specification, inspection may include:
Hydrostatic Shell Test
Checks the pressure boundary for leakage and structural integrity under the specified test conditions.
Seat Leakage Test
Checks the sealing performance of the valve seat.
Backseat Test
Where applicable, the backseat arrangement can be tested according to the applicable standard and specification.
Dimensional Inspection
Important dimensions may include:
Face-to-face length
End-to-end dimensions
Flange dimensions
Bore dimensions
Stem dimensions
Overall height
Material Verification
Material certificates should be checked against the purchase order and applicable material specifications. PMI may also be required for selected alloy or stainless-steel components.
NDE
Depending on the valve material, design and project requirements, NDE may include:
Radiographic testing
Ultrasonic testing
Magnetic particle testing
Liquid penetrant testing
Not every valve requires every NDE method. The inspection plan should be agreed before production.
cast steel globe valve factory
Our engineering team can review your specification and help confirm the appropriate cast steel globe valve configuration, testing requirements and documentation before quotation.
FAQ
What is a cast steel globe valve used for?
A cast steel globe valve is mainly used for flow regulation, throttling and shutoff in industrial piping. It is commonly used in steam, oil, gas, petrochemical, chemical and power-generation systems.
Is a globe valve suitable for throttling?
Yes. Globe valves are generally well suited to throttling because the disc position can be adjusted progressively to control flow. However, the pressure drop and potential erosion should be evaluated for severe throttling service.
What is the most common material for a cast steel globe valve?
ASTM A216 WCB is one of the most common cast carbon steel body materials for industrial globe valves. Other materials such as LCB, WC6, WC9 and CF8M may be selected for low-temperature, high-temperature or corrosive service.
What is API 623?
API 623 is an API standard for steel globe valves with flanged and butt-welding ends and bolted bonnets. It is commonly referenced in petroleum, petrochemical and related industrial applications.
What is the difference between API 623 and ASME B16.34?
API 623 specifically addresses steel globe valves, while ASME B16.34 covers broader requirements for applicable flanged, threaded and welding-end valves, including pressure-temperature ratings, materials, dimensions, testing and marking.
Is WCB suitable for high-temperature service?
WCB can be used for many general industrial services, but suitability depends on the actual pressure-temperature condition and applicable material rating. For higher-temperature applications, alloy steel grades such as WC6 or WC9 may be considered.
What is the difference between a globe valve and a gate valve?
A globe valve is generally preferred for throttling and flow regulation, while a gate valve is mainly used for isolation. Globe valves normally produce more pressure drop, whereas gate valves can provide a relatively low-resistance flow path when fully open.