1/2″-1500LB-RF Double Block Y Pattern Globe Valve
Description
Technical Data Sheet
Product: Double Block Y-Pattern Globe Valve
Model / Size: 1/2″ – 1500LB – RF
Configuration: Two Y-pattern globe valves welded into a single integrated body assembly
1. Product Description
This valve consists of two Y-pattern globe valves welded together to form a compact, single-unit double block isolation assembly. The Y-pattern design offers lower flow resistance compared to standard globe valves, while the double block configuration provides two independent sealing barriers. This assembly is ideal for applications requiring positive isolation, such as instrument impulse lines, high-pressure bypass loops, and critical process isolation where safety and leak-tightness are paramount. Each valve operates independently, allowing for testing, bleeding, or venting between the two blocks.
2. Basic Parameters
| Item | Parameter |
|---|---|
| Nominal Size | 1/2 inch (DN 15) per valve; assembly size based on common inlet/outlet |
| Pressure Class | Class 1500LB (equivalent to PN 260 bar) |
| End Connections | RF (Raised Face Flanges) – inlet and outlet flanges |
| Configuration | Two Y-pattern globe valves welded body-to-body |
| Structure Type | Outside Screw & Yoke (OS&Y), Y-pattern (angled stem, 45° or similar) |
| Operation | Each valve independently operated (handwheels or levers) |
3. Design Standards
| Item | Standard |
|---|---|
| Design & Manufacture | API 602 (Compact steel gate, globe, and check valves) – applicable for individual valve design; assembly per manufacturer’s standard |
| Pressure-Temperature Rating | ASME B16.34 |
| Flange Dimensions | ASME B16.5 (RF flanges) |
| Face-to-Face Dimensions | Manufacturer’s standard (assembly length) |
| Inspection & Testing | API 598 (or ISO 5208); double block isolation tested per API 6D / customer specification |
| Welding | Body-to-body weld per ASME Section IX |
4. Bill of Materials (Typical Configuration)
| Part Name | Material (Typical Options) | Remarks |
|---|---|---|
| Valve Bodies (x2) | A105 (carbon steel) / A182 F316 (stainless steel) / F22 (Cr-Mo) | Welded together to form integral assembly |
| Disc (x2) | A105 + hardfacing / F316 + hardfacing | Stellite 6 or 21 hardfacing |
| Seat (x2) | Integral body seat with hardfacing | Stellite 6 overlay |
| Stem (x2) | A182 F6a (13Cr) / F316 / F304 | Precipitation hardened or austenitic SS |
| Bonnet (x2) | Same material as body | Bolted bonnet with gasket |
| Packing (x2) | Flexible graphite with anti-extrusion rings | Low-emission packing system |
| Handwheel (x2) | Carbon steel / Ductile iron | Independent operation |
| Flange Ends | RF flanges per ASME B16.5 | Inlet and outlet |
5. Dimensions & Weight (Reference)
| Item | Value |
|---|---|
| Overall Length (End-to-End) | Approx. 200 ~ 250 mm (manufacturer dependent) |
| Overall Height | Approx. 250 ~ 300 mm (including handwheels) |
| Flange Size | 1/2″ RF flanges per ASME B16.5 Class 1500 |
| Handwheel Diameter (each) | Approx. 100 ~ 120 mm |
| Approx. Weight | 10 ~ 16 kg (depending on material) |
Note: Dimensions and weights are typical values for welded double block Y-pattern globe valves and may vary by manufacturer.
6. Operating Conditions
| Item | Parameter |
|---|---|
| Suitable Media | High-pressure steam, water, oil, gas, hydrocarbons, corrosive fluids |
| Temperature Range (Carbon Steel) | -29°C ~ 425°C |
| Temperature Range (Alloy Steel) | -29°C ~ 538°C |
| Temperature Range (Stainless Steel) | -196°C ~ 538°C |
| Max. Allowable Pressure | Approx. 26.0 MPa (260 bar) at ambient temperature (38°C) |
7. Testing & Inspection
| Test | Requirement |
|---|---|
| Shell Strength Test (each valve) | 1.5 times rated pressure; no leakage |
| High-Pressure Seat Test (each valve) | 1.1 times rated pressure; no visible leakage |
| Low-Pressure Pneumatic Test (each valve) | 0.6 MPa compressed air; seat leakage within allowable limits |
| Double Block Isolation Test | Both valves closed; pressure applied between blocks; no pressure rise or leakage observed (per API 6D or customer requirement) |
| Body-to-Body Weld Examination | 100% visual inspection; optional PT or RT per specification |
| Operational Test | Full stroke cycling of each valve under rated differential pressure |
8. Features & Benefits
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Double Block Isolation: Two independent globe valves in one assembly provide positive shut-off with the ability to test, vent, or monitor the cavity between blocks.
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Compact Design: Welded integration eliminates separate piping connections between valves, reducing potential leak paths and installation space.
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Y-Pattern Flow Path: Lower pressure drop compared to standard globe valves; ideal for high-flow applications requiring throttling or isolation.
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Independent Operation: Each valve can be operated separately, allowing sequential opening/closing and intermediate cavity access.
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High Pressure Capability: Class 1500 rating suitable for high-pressure systems in refineries, power plants, and chemical facilities.
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Fugitive Emission Compliance: Stem packing can be designed to meet ISO 15848 or TA-Luft requirements.
9. Important Notes
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Operation Sequence: When used as a double block assembly, typically the upstream valve is opened first and closed last to protect the downstream valve from full system pressure.
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Cavity Between Valves: A bleed or vent port can be added (optional) to relieve pressure trapped between the two blocks before maintenance.
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Installation Orientation: Valve assembly is typically installed with handwheels accessible; orientation may affect cavity access.
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Welded Construction: The body-to-body weld is permanent; do not attempt to disassemble or modify the weld joint.
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Flow Direction: Each Y-pattern valve has a preferred flow direction (usually indicated by arrow on body). Ensure correct orientation of the assembly relative to system flow.
If you require specific details such as NACE MR0175 certification, fugitive emission testing, or a custom bleed port arrangement, please let me know and I can supplement the data sheet accordingly.
